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Sample records for pyroelectric infrared detectors

  1. Effect of space exposure on pyroelectric infrared detectors (A0135)

    Science.gov (United States)

    Robertson, J. B.; Clark, I. O.; Crouch, R. K.

    1984-01-01

    The effects of long-duration space exposure and launch environment on the performance of pyroelectric detectors which is important for the prediction of performance degradation, setting exposure limits, or determining shielding requirements was investigated. Air pollution monitoring and thermal mapping of the Earth, which includes the remote sensing of aerosols and limb scanning infrared radiometer projects, requires photodetection in the 6- to 20 micro m region of the spectrum. Pyroelectric detectors can detect radiation in the 1- to 100 micro m region while operating at room temperature. This makes tahe pyroelectric detector a prime candidate to fill the thermal infrared detector requirements.

  2. Infrared Responsivity of a Pyroelectric Detector with a Single-Wall Carbon Nanotube Coating

    Energy Technology Data Exchange (ETDEWEB)

    Theocharous, E.; Engtrakul, C.; Dillon, A. C.; Lehman, J.

    2008-08-01

    The performance of a 10 mm diameter pyroelectric detector coated with a single-wall carbon nanotube (SWCNT) was evaluated in the 0.8 to 20 {micro}m wavelength range. The relative spectral responsivity of this detector exhibits significant fluctuations over the wavelength range examined. This is consistent with independent absorbance measurements, which show that SWCNTs exhibit selective absorption bands in the visible and near-infrared. The performance of the detector in terms of noise equivalent power and detectivity in wavelength regions of high coating absorptivity was comparable with gold-black-coated pyroelectric detectors based on 50 {micro}m thick LiTaO{sub 3} crystals. The response of this detector was shown to be nonlinear for DC equivalent photocurrents >10{sup -9} A, and its spatial uniformity of response was comparable with other pyroelectric detectors utilizing gold-black coatings. The nonuniform spectral responsivity exhibited by the SWCNT-coated detector is expected to severely restrict the use of SWCNTs as black coatings for thermal detectors. However, the deposition of SWCNT coatings on a pyroelectric crystal followed by the study of the prominence of the spectral features in the relative spectral responsivity of the resultant pyroelectric detectors is shown to provide an effective method for quantifying the impurity content in SWCNT samples.

  3. True differential pyroelectric infrared detector with improved D* test results with analysis

    Science.gov (United States)

    Doctor, Alan

    2016-10-01

    Pyroelectric infrared detectors are used in many commercial and industrial applications. Typically these devices have been "single ended" and thus any electronic perturbation from a non-detector related noise source such as line frequency interference or microprocessor clock and other sources of electronic noise can be coupled onto the detector's output signal. We have solved this problem by employing a rather unique connection which also provides an increase in the signal to noise of any pyroelectric detector by a factor of the square root of 2 or by about 1.41 times greater than devices not utilizing this connection. Many devices using this connection have been built, fully tested and the data analyzed which provide a true differential or double ended output and the increase in D* as predicted. This scheme will work with any pyroelectric material (LTO, DLATGS, PLZT, PVDF etc.) with current or voltage mode impedance conversion and configurations such as parallel or series with and without temperature fluctuation compensation and of course with standard single elements. This talk will present this data and conclusions regarding the approach.

  4. Characterization of a Polymer-Based MEMS Pyroelectric Infrared Detector

    Science.gov (United States)

    2007-03-01

    engineered protein in hydrogels tailors stimuli-responsive characteristics.” Nature, vol 4, pp 298 – 302, Apr 2005. [8] Brott, Lawrence L...CR Detector Pre- amp Φe (t) 38 three regimes can be seen in Figure 14, which represents the voltage reponsivity...detector needs amplification, using one of the two circuits shown in Figure 19 or 20. In lieu of this circuit, a voltage pre- amp was used

  5. Potassium dihydrogen phosphate and potassium tantalate niobate pyroelectric materials and far-infrared detectors

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, H. B. [Lawrence Berkeley Lab., CA (United States); [California Univ., Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

    1993-10-01

    This thesis discusses characterization of two ferroelectric materials and the fabrication of bolometers. Potassium tantalate niobate (KTN) and potassium dihydrogen phosphate (KDP) are chosen because they can be optimized for operation near 100K. Chap. 2 reviews the physics underlying pyroelectric materials and its subclass of ferroelectric materials. Aspects of pyroelectric detection are discussed in Chap. 3 including measurement circuit, noise sources, and effects of materials properties on pyroelectric response. Chap. 4 discusses materials selection and specific characteristics of KTN and KDP; Chap. 5 describes materials preparation; and Chap. 6 presents detector configuration and a thermal analysis of the pyroelectric detector. Electrical techniques used to characterize the materials and devices and results are discussed in Chap. 7 followed by conclusions on feasibility of KDP and KTN pyroelectric detectors in Chap. 8.

  6. 3D-Printing of inverted pyramid suspending architecture for pyroelectric infrared detectors with inhibited microphonic effect

    Science.gov (United States)

    Xu, Qing; Zhao, Xiangyong; Li, Xiaobing; Deng, Hao; Yan, Hong; Yang, Linrong; Di, Wenning; Luo, Haosu; Neumann, Norbert

    2016-05-01

    A sensitive chip with ultralow dielectric loss based on Mn doped PMNT (71/29) has been proposed for high-end pyroelectric devices. The dielectric loss at 1 kHz is 0.005%, one order lower than the minimum value reported so far. The detective figure of merit (Fd) is up to 92.6 × 10-5 Pa-1/2 at 1 kHz and 53.5 × 10-5 Pa-1/2 at 10 Hz, respectively. In addition, an inverted pyramid suspending architecture for supporting the sensitive chip has been designed and manufactured by 3D printing technology. The combination of this sensitive chip and the proposed suspending architecture largely enhances the performance of the pyroelectric detectors. The responsivity and specific detectivity are 669,811 V/W and 3.32 × 109 cm Hz1/2/W at 10 Hz, respectively, 1.9 times and 1.5 times higher than those of the highest values in literature. Furthermore, the microphonic effect can be largely inhibited according to the theoretical and experimental analysis. This architecture will have promising applications in high-end and stable pyroelectric infrared detectors.

  7. Evaluation of dome-input geometry for pyroelectric detectors

    Science.gov (United States)

    Zeng, J.; Hanssen, L. M.; Eppeldauer, G. P.

    2013-06-01

    Dome-input pyroelectric radiometers with different black coatings were developed to extend the spectral responsivity scale from near infrared (NIR) to 20 μm. The reflective dome with shiny gold-coating has been known to be an efficient light trap to enhance the detector absorptance and to minimize spectral responsivity variation. The enhancement of spectral responsivity using reflective dome relies on optical characterization of black coating on detector, reflectance of dome reflector, and input aperture dimension, etc. We report a comparison of spectral responsivity of dome-input pyroelectric radiometers measured with/without dome-trap from 2.4 μm to 14 μm using the Infrared Spectral Comparator Facility (IRSCF) at NIST. The results show 4 % to 8 % gain of responsivity for two dome-input pyroelectric detectors, with reduced structure of spectral responsivity. The uncertainty of dome-input pyroelectric radiometer calibrations is approximately 2 % (k = 2).

  8. Design of the Monocular Pyroelectric Infrared Detector%一种热释电红外探测器的单目设计

    Institute of Scientific and Technical Information of China (English)

    崔永俊; 贾磊; 王希鹏; 赵秀梅; 薛志勇; 杜文略

    2016-01-01

    To solve the problems of high false alarm rate, low sensitivity and unable to locate intrusion targets and other issues in ordinary pyroelectric infrared detection technology, the design based on compound eye structure is proposed for pyroelectric infrared detector. Combining the advantages of pyroelectric infrared detection, including good concealment, stable performance, environmental adaptability, large viewing angle of compound eye, small size and high sensitivity, the charge signal on pyroelectric material is converted into voltage signal, and output after filtering and amplifying. Experiments show that the monocular of the designed pyroelectric infrared detector can detect intrusion target within fifteen meters, and output pulse level as an alarm signal.%为解决普通热释电的红外探测技术误报率高、敏感度低且不能对入侵目标进行定位等问题,提出了一种基于热释电红外探测器的复眼结构的设计.结合热释电红外探测隐蔽性好、性能稳定、环境适应能力强、复眼视场角大、体积小且灵敏度高等优势,将热释材料上的电荷信号转换为电压信号,经滤波、放大后输出.通过实验表明,采用该热释电红外探测器的单目可以检测到15 m内的入侵目标,并输出脉冲电平作为报警信号.

  9. 大电流宽频带热释电红外探测器优化设计%Optimization Design of Large current broadband pyroelectric infrared detector

    Institute of Scientific and Technical Information of China (English)

    王芳; 杨桂勇; 宋艳; 颜延志; 马春旺

    2011-01-01

    本文提出了一种大电流宽频带的热释电红外探测器的优化设计方法.在分析热释电输出电压响应的基础上,结合热辐射探测的特点,提出了新的仿真模型,实际电路与仿真数据基本吻合.通过采用双极型结型场效应管(BJFET)和改变热释电时间常数等方法解决了热释电前置放大器输出信号弱和通频带窄的关键问题.%This paper presents a large current broadband pyroelectric infrared detector optimal design method. The analysis of the pyroelectric response of the output voltage based on the combination of the characteristics of thermal radiation detection, put forword a new simulation model, and the actual circuit is basically consistent with simulation data. Through using bipolar JFET (BJFET) and changing the time constant and so on, we will improve the low - output and narrow bands which were the key issues of pyroelectric preamplifier.

  10. 热释电红外探测器PZT晶片粘接质量控制%Quality Control of the PZT Wafer Bonding in Pyroelectric Infrared Detector

    Institute of Scientific and Technical Information of China (English)

    黄江平; 冯江敏; 王羽; 苏玉辉; 信思树; 李玉英

    2013-01-01

    热释电红外探测器芯片研制中,晶片粘接是芯片研制中的关键工艺之一。本文详细论述了粘接胶的选择依据及晶片粘接质量控制。确定了适合器件研制的粘接胶和粘胶工艺流程。对粘接中出现的问题及解决办法进行了讨论。研制出了完全能满足器件工艺要求的热释电探测器PZT晶片。%The wafer bonding is one of the key technologies in pyroelectric infrared detector chip development. This paper discusses the selection basis of bonding glue and quality control of wafer bonding in details, also determines the adhesive glue and the technology suitable for detector development, and analyzes the problems and the resolution method in the course of wafer bonding. The PZT wafer that can fully meet the technology requirements of pyroelectric detector is provided.

  11. Responsivity Calibration of Pyroelectric Terahertz Detectors

    CERN Document Server

    Berry, Christopher W; Jarrahi, Mona

    2014-01-01

    There has been a significant advancement in terahertz radiation sources in the past decade, making milliwatt terahertz power levels accessible in both continuous-wave and pulsed operation. Such high-power terahertz radiation sources circumvent the need for cryogenic-cooled terahertz detectors such as semiconductor bolometers and necessitate the need for new types of calibrated, room-temperature terahertz detectors. Among various types of room-temperature terahertz detectors, pyroelectric detectors are one of the most widely used detectors, which can offer wide dynamic range, broad detection bandwidth, and high sensitivity levels. In this article, we describe the calibration process of a commercially available pyroelectric detector (Spectrum Detector, Inc, SPI-A-65 THz), which incorporates a 5 mm diameter LiTaO3 detector with an organic terahertz absorber coating.

  12. 基于弛豫铁电单晶的红外热释电探测器研究%Pyroelectric infrared detector with relax-based ferroelectric single crystals

    Institute of Scientific and Technical Information of China (English)

    马学亮; 邵秀梅; 于月华; 李言谨

    2012-01-01

    研究了新型热释电材料驰豫铁电单晶(1-x)Pb(Mg1/3Nbz/a)O3-xPbTiO3(PMNT)的低损伤减薄工艺、电极成型和耦合封装等关键技术,研制了基于PMNT的单元热释电探测器。对减薄后约30um晶片材料性能的测试分析表明,部分样品的热释电系数约为9.0×10^-4C/m^2K,无明显衰减。采用低噪声电路提取单元探测器的微弱热释电电流,对所研制的单元探测器性能进行了测试分析。%PMNT single crystal is a novel pyroelectric material with superior pyroelectric performance. The fabrication of pyroelectirc infrared detectors based on PMNT single crystal, including lapping and polishing of the crystal, metallization and assembly,is carried out. The pyroelectric coefficient of PMNT chip with thickness of 30 um is measured and the results indicate that the pyroelectric coefficients of some chips are 9.0 × 10^-4 C/m2K, similar to that of the PMNT single crystal with thickness of 500 um. Weak pyroelectric current is extracted by a low-noise circuit, and the performance of the fabricated detector is tested and analyzed.

  13. Fabrication and Properties of the Multi-layer Pyroelectric Thin Film Infrared Detectors%复合热释电薄膜红外探测器的制备和性能测试

    Institute of Scientific and Technical Information of China (English)

    王三红; 吴小清; 姚熹

    2001-01-01

    为解决热释电薄膜红外探测器中的热损失问题,引入了复合热释电薄膜的概念.它利用多孔二氧化硅具有的低热导率特点,有效地减少了热量从热释电层向衬底的热扩散.利用溶胶-凝胶和金属有机物热分解等工艺制备的复合热释电薄膜红外探测器,在温度为420K、频率为10Hz时,电压响应率约为1400V/W,探测器的星探测率D(420,10,2)为9.3×107cm.Hz1/2/W.%In order to reduce the thermal dissipation from the pyroelectric film to the substrate and meet the needs of integration with silicon, the multi-layer pyroelectric thin film (MPTF) was introduced. It is mainly composed of pyroelectric sensitive layer-lead titanate, thermal isolating layer-porous silicon dioxide film, and the buffer layer-dense silicon dioxide film. A pyroelectric measuring system was built to measure the infrared response of the detector. The voltage response and the specific detectivity of the detector were also given.

  14. Abnormal Activity Detection Using Pyroelectric Infrared Sensors

    Directory of Open Access Journals (Sweden)

    Xiaomu Luo

    2016-06-01

    Full Text Available Healthy aging is one of the most important social issues. In this paper, we propose a method for abnormal activity detection without any manual labeling of the training samples. By leveraging the Field of View (FOV modulation, the spatio-temporal characteristic of human activity is encoded into low-dimension data stream generated by the ceiling-mounted Pyroelectric Infrared (PIR sensors. The similarity between normal training samples are measured based on Kullback-Leibler (KL divergence of each pair of them. The natural clustering of normal activities is discovered through a self-tuning spectral clustering algorithm with unsupervised model selection on the eigenvectors of a modified similarity matrix. Hidden Markov Models (HMMs are employed to model each cluster of normal activities and form feature vectors. One-Class Support Vector Machines (OSVMs are used to profile the normal activities and detect abnormal activities. To validate the efficacy of our method, we conducted experiments in real indoor environments. The encouraging results show that our method is able to detect abnormal activities given only the normal training samples, which aims to avoid the laborious and inconsistent data labeling process.

  15. Abnormal Activity Detection Using Pyroelectric Infrared Sensors.

    Science.gov (United States)

    Luo, Xiaomu; Tan, Huoyuan; Guan, Qiuju; Liu, Tong; Zhuo, Hankz Hankui; Shen, Baihua

    2016-06-03

    Healthy aging is one of the most important social issues. In this paper, we propose a method for abnormal activity detection without any manual labeling of the training samples. By leveraging the Field of View (FOV) modulation, the spatio-temporal characteristic of human activity is encoded into low-dimension data stream generated by the ceiling-mounted Pyroelectric Infrared (PIR) sensors. The similarity between normal training samples are measured based on Kullback-Leibler (KL) divergence of each pair of them. The natural clustering of normal activities is discovered through a self-tuning spectral clustering algorithm with unsupervised model selection on the eigenvectors of a modified similarity matrix. Hidden Markov Models (HMMs) are employed to model each cluster of normal activities and form feature vectors. One-Class Support Vector Machines (OSVMs) are used to profile the normal activities and detect abnormal activities. To validate the efficacy of our method, we conducted experiments in real indoor environments. The encouraging results show that our method is able to detect abnormal activities given only the normal training samples, which aims to avoid the laborious and inconsistent data labeling process.

  16. Wireless intelligent alarm technology with pyroelectric infrared sensor

    Science.gov (United States)

    Chen, Xiao

    2009-07-01

    Aiming at the defects of monitoring conducted by man in the conventional practice, we study the passive intelligent automatic alarm technology based on the pyroelectric infrared sensor and wireless communication technology. The designed passive infrared wireless alarm is composed of pyroelectric infrared sensors, infrared special chip BISS0001 and their peripheral circuits. When someone enters into the detecting and monitoring range, the alarm will detect the infrared ray of the human radiation by the contactless form and detect the signals of circuit output. Then it translates them into low frequency signals relative with human sports speed, distance and direction, produce corresponding output signals through amplifying by the back state controller, switch on the work power of the wireless transmitting circuit and make it emit the alarm signals. The system enhances the monitoring level and effects and possesses many advantages such as wide detecting range, long detecting distance and high reliability.

  17. Pyroelectric materials as electronic pulse detectors of ultraheavy nuclei

    Science.gov (United States)

    Simpson, J. A.; Tuzzolino, A. J.

    1984-01-01

    The design and testing of ultraheavy-nucleus pulse detectors based on pyroelectric materials are reported, extending the preliminary findings of Tuzzolino (1983) and Simpson and Tuzzolino (1983). Uranium-ion beams of about 240 MeV/u are detected by a 39.5-micron-thick Si detector, degraded to about 175 MeV/u by Al absorbers, and then strike 700-micron-thick polyvinylidene fluoride or 1000-micron-thick LiTaO3 pyroelectric samples. Both detector systems are connected to a coincidence circuit via charge-sensitive preamplifiers, shaping amplifiers with 30-microsec effective time constants, and electronic discriminators. Sample spectra are shown, and the pulse heights measured are found to agree with theoretical calculations to within a factor of about 2. The response of the pyroelectric materials is found to be unaffected by exposure to about 10 Mrad of 2-7-MeV/u heavy ion radiation. With further study and improvement of the detection sensitivity, devices of this type could be applied to large-area space measurements of low ultraheavy-ion fluxes.

  18. Testing of InGaAs, microbolometer and pyroelectric detectors in support of the EarthCARE mission

    Science.gov (United States)

    Hopkinson, Gordon; Gomez Rojas, Luis; Skipper, Mark; Meynart, Roland

    2008-10-01

    A test programme for infrared detectors in support of the EarthCARE mission is discussed. Commercially available linear InGaAs arrays from XenICs, Belgium (cut-off wavelengths 1.7, 2.2 and 2.5 μm), 384 x 288 amorphous silicon microbolometer arrays from ULIS, France and un-windowed single element lithium tantalate pyroelectric detectors from Infratec, Germany have been studied in detail to assess their suitability for EarthCARE and to provide performance data to aid in the design of the flight instruments. Tests included radiation resistance (cobalt60 and 60 MeV protons plus a heavy ion latch-up test for the InGaAs and microbolometer arrays), dark signal, noise, output stability, linearity, crosstalk and spectral response. In addition, the pyroelectric detectors were tested for low microphony.

  19. Quantitative ultrasonic computed tomography using phase-insensitive pyroelectric detectors.

    Science.gov (United States)

    Zeqiri, Bajram; Baker, Christian; Alosa, Giuseppe; Wells, Peter N T; Liang, Hai-Dong

    2013-08-07

    The principle of using ultrasonic computed tomography (UCT) clinically for mapping tissue acoustic properties was suggested almost 40 years ago. Despite strong research activity, UCT been unable to rival its x-ray counterpart in terms of the ability to distinguish tissue pathologies. Conventional piezoelectric detectors deployed in UCT are termed phase-sensitive (PS) and it is well established that this property can lead to artefacts related to refraction and phase-cancellation that mask true tissue structure, particularly for reconstructions involving attenuation. Equally, it has long been known that phase-insensitive (PI) detectors are more immune to this effect, although sufficiently sensitive devices for clinical use have not been available. This paper explores the application of novel PI detectors to UCT. Their operating principle is based on exploiting the pyroelectric properties of the piezoelectric polymer polyvinylidene difluoride. An important detector performance characteristic which makes it particularly suited to UCT, is the lack of directionality of the PI response, relative to the PS detector mode of operation. The performance of the detectors is compared to conventional PS detection methods, for quantitatively assessing the attenuation distribution within various test objects, including a two-phase polyurethane phantom. UCT images are presented for a range of single detector apertures; tomographic reconstruction images being compared with the known structure of phantoms containing inserts as small as 3 mm, which were readily imaged. For larger diameter inserts (>10 mm), the transmitter-detector combination was able to establish the attenuation coefficient of the insert to within ±10% of values determined separately from plane-wave measurements on representative material plaques. The research has demonstrated that the new PI detectors are significantly less susceptible to refraction and phase-cancellation artefacts, generating realistic images in

  20. Graphene-based, mid-infrared, room-temperature pyroelectric bolometers with ultrahigh temperature coefficient of resistance

    CERN Document Server

    Sassi, U; Nanot, S; Bruna, M; Borini, S; Milana, S; De Fazio, D; Zhuang, Z; Lidorikis, E; Koppens, F H L; Ferrari, A C; Colli, A

    2016-01-01

    Graphene is ideally suited for photonic and optoelectronic applications, with a variety of photodetectors (PDs) in the visible, near-infrared (NIR), and THz reported to date, as well as thermal detectors in the mid-infrared (MIR). Here, we present a room temperature-MIR-PD where the pyroelectric response of a LiNbO3 crystal is transduced with high gain (up to 200) into resistivity modulation for graphene, leading to a temperature coefficient of resistance up to 900%/K, two orders of magnitude higher than the state of the art, for a device area of 300x300um2. This is achieved by fabricating a floating metallic structure that concentrates the charge generated by the pyroelectric substrate on the top-gate capacitor of the graphene channel. This allows us to resolve temperature variations down to 15umK at 1 Hz, paving the way for a new generation of detectors for MIR imaging and spectroscopy

  1. EMD-Based Symbolic Dynamic Analysis for the Recognition of Human and Nonhuman Pyroelectric Infrared Signals.

    Science.gov (United States)

    Zhao, Jiaduo; Gong, Weiguo; Tang, Yuzhen; Li, Weihong

    2016-01-20

    In this paper, we propose an effective human and nonhuman pyroelectric infrared (PIR) signal recognition method to reduce PIR detector false alarms. First, using the mathematical model of the PIR detector, we analyze the physical characteristics of the human and nonhuman PIR signals; second, based on the analysis results, we propose an empirical mode decomposition (EMD)-based symbolic dynamic analysis method for the recognition of human and nonhuman PIR signals. In the proposed method, first, we extract the detailed features of a PIR signal into five symbol sequences using an EMD-based symbolization method, then, we generate five feature descriptors for each PIR signal through constructing five probabilistic finite state automata with the symbol sequences. Finally, we use a weighted voting classification strategy to classify the PIR signals with their feature descriptors. Comparative experiments show that the proposed method can effectively classify the human and nonhuman PIR signals and reduce PIR detector's false alarms.

  2. Infrared detectors

    CERN Document Server

    Rogalski, Antonio

    2010-01-01

    This second edition is fully revised and reorganized, with new chapters concerning third generation and quantum dot detectors, THz detectors, cantilever and antenna coupled detectors, and information on radiometry and IR optics materials. Part IV concerning focal plane arrays is significantly expanded. This book, resembling an encyclopedia of IR detectors, is well illustrated and contains many original references … a really comprehensive book.-F. Sizov, Institute of Semiconductor Physics, National Academy of Sciences, Kiev, Ukraine

  3. EMD-Based Symbolic Dynamic Analysis for the Recognition of Human and Nonhuman Pyroelectric Infrared Signals

    Directory of Open Access Journals (Sweden)

    Jiaduo Zhao

    2016-01-01

    Full Text Available In this paper, we propose an effective human and nonhuman pyroelectric infrared (PIR signal recognition method to reduce PIR detector false alarms. First, using the mathematical model of the PIR detector, we analyze the physical characteristics of the human and nonhuman PIR signals; second, based on the analysis results, we propose an empirical mode decomposition (EMD-based symbolic dynamic analysis method for the recognition of human and nonhuman PIR signals. In the proposed method, first, we extract the detailed features of a PIR signal into five symbol sequences using an EMD-based symbolization method, then, we generate five feature descriptors for each PIR signal through constructing five probabilistic finite state automata with the symbol sequences. Finally, we use a weighted voting classification strategy to classify the PIR signals with their feature descriptors. Comparative experiments show that the proposed method can effectively classify the human and nonhuman PIR signals and reduce PIR detector’s false alarms.

  4. The development of potassium tantalate niobate thin films for satellite-based pyroelectric detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, Hilary B.B. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

    1997-05-01

    Potassium tantalate niobate (KTN) pyroelectric detectors are expected to provide detectivities, of 3.7 x 1011 cmHz 1/2W-1 for satellite-based infrared detection at 90 K. The background limited detectivity for a room-temperature thermal detector is 1.8 x 1010 cmHz1/2W-1 . KTN is a unique ferroelectric for this application because of the ability to tailor the temperature of its pyroelectric response by adjusting its ratio of tantalum to niobium. The ability to fabricate high quality KTN thin films on Si-based substrates is crucial to the development of KTN pyroelectric detectors. SixNymembranes created on the Si substrate will provide the weak thermal link necessary to reach background limited detectivities. The device dimensions obtainable by thin film processing are expected to increase the ferroelectric response by 20 times over bulk fabricated KTN detectors. In addition, microfabrication techniques allow for easier array development. This is the first reported attempt at growth of KTN films on Si-based substrates. Pure phase perovskite films were grown by pulsed laser deposition on SrRuO3/Pt/Ti/SixNy/Si and SrRuO3/SixNy/Si structures; room temperature dielectric permittivities for the KTN films were 290 and 2.5, respectively. The dielectric permittivity for bulk grown, single crystal KTN is ~380. In addition to depressed dielectric permittivities, no ferroelectric hysteresis was found between 80 and 300 K for either structure. RBS, AES, TEM and multi-frequency dielectric measurements were used to investigate the origin of this apparent lack of ferroelectricity. Other issues addressed by this dissertation include: the role of oxygen and target density during pulsed laser deposition of KTN thin films; the use of YBCO, LSC and Pt as direct contact bottom electrodes to the KTN films, and the adhesion of the bottom

  5. The development of potassium tantalate niobate thin films for satellite-based pyroelectric detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, H B.B. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

    1997-05-01

    Potassium tantalate niobate (KTN) pyroelectric detectors are expected to provide detectivities, of 3.7 x 10{sup 11} cmHz {sup {1/2}}W{sup {minus}1} for satellite-based infrared detection at 90 K. The background limited detectivity for a room-temperature thermal detector is 1.8 x 10{sup 10} cmHz{sup {1/2}}W{sup {minus}1}. KTN is a unique ferroelectric for this application because of the ability to tailor the temperature of its pyroelectric response by adjusting its ratio of tantalum to niobium. The ability to fabricate high quality KTN thin films on Si-based substrates is crucial to the development of KTN pyroelectric detectors. Si{sub x}N{sub y} membranes created on the Si substrate will provide the weak thermal link necessary to reach background limited detectivities. The device dimensions obtainable by thin film processing are expected to increase the ferroelectric response by 20 times over bulk fabricated KTN detectors. In addition, microfabrication techniques allow for easier array development. This is the first reported attempt at growth of KTN films on Si-based substrates. Pure phase perovskite films were grown by pulsed laser deposition on SrRuO{sub 3}/Pt/Ti/Si{sub x}N{sub y}/Si and SrRuO{sub 3}/Si{sub x}N{sub y}/Si structures; room temperature dielectric permittivities for the KTN films were 290 and 2.5, respectively. The dielectric permittivity for bulk grown, single crystal KTN is {approximately}380. In addition to depressed dielectric permittivities, no ferroelectric hysteresis was found between 80 and 300 K for either structure. RBS, AES, TEM and multi-frequency dielectric measurements were used to investigate the origin of this apparent lack of ferroelectricity. Other issues addressed by this dissertation include: the role of oxygen and target density during pulsed laser deposition of KTN thin films; the use of YBCO, LSC and Pt as direct contact bottom electrodes to the KTN films, and the adhesion of the bottom electrode layers to Si{sub x}N{sub y}/Si.

  6. Human Movement Detection and Identification Using Pyroelectric Infrared Sensors

    Directory of Open Access Journals (Sweden)

    Jaeseok Yun

    2014-05-01

    Full Text Available Pyroelectric infrared (PIR sensors are widely used as a presence trigger, but the analog output of PIR sensors depends on several other aspects, including the distance of the body from the PIR sensor, the direction and speed of movement, the body shape and gait. In this paper, we present an empirical study of human movement detection and identification using a set of PIR sensors. We have developed a data collection module having two pairs of PIR sensors orthogonally aligned and modified Fresnel lenses. We have placed three PIR-based modules in a hallway for monitoring people; one module on the ceiling; two modules on opposite walls facing each other. We have collected a data set from eight subjects when walking in three different conditions: two directions (back and forth, three distance intervals (close to one wall sensor, in the middle, close to the other wall sensor and three speed levels (slow, moderate, fast. We have used two types of feature sets: a raw data set and a reduced feature set composed of amplitude and time to peaks; and passage duration extracted from each PIR sensor. We have performed classification analysis with well-known machine learning algorithms, including instance-based learning and support vector machine. Our findings show that with the raw data set captured from a single PIR sensor of each of the three modules, we could achieve more than 92% accuracy in classifying the direction and speed of movement, the distance interval and identifying subjects. We could also achieve more than 94% accuracy in classifying the direction, speed and distance and identifying subjects using the reduced feature set extracted from two pairs of PIR sensors of each of the three modules.

  7. An infrared-driven flexible pyroelectric generator for non-contact energy harvester.

    Science.gov (United States)

    Zhao, Tingting; Jiang, Weitao; Liu, Hongzhong; Niu, Dong; Li, Xin; Liu, Weihua; Li, Xuan; Chen, Bangdao; Shi, Yongsheng; Yin, Lei; Lu, Bingheng

    2016-04-21

    In recent years, energy harvesting technologies, which can scavenge many kinds of energies from our living environment to power micro/nanodevices, have attracted increasing attention. However, remote energy transmission, flexibility and electric waveform controllability remain the key challenges for wireless power supply by an energy harvester. In this paper, we design a new infrared-driven non-contact pyroelectric generator for harvesting heat energy, which avoids direct contact between the pyroelectric generator and heat source and realizes remote energy transfer exploiting the photothermal and penetrability of infrared light. The output voltage (under the input impedance of 100 MOhm) and short-circuit current of the pyroelectric generator consisting of a CNT/PVDF/CNT layer (20 mm × 5 mm × 100 μm) can be as large as 1.2 V and 9 nA, respectively, under a 1.45 W cm(-2) near-infrared laser (808 nm). We also demonstrate the means by which the pyroelectric generator can modulate square waveforms with controllable periods through irradiation frequency, which is essential for signal sources and medical stimulators. The overshoot of square waveforms are in a range of 9.0%-13.1% with a rise time of 120 ms. The prepared pyroelectric generator can light a liquid crystal display (LCD) in a vacuum chamber from outside. This work paves the way for non-contact energy harvesting for some particular occasions where near-field energy control is not available.

  8. Development of pyroelectric neutron source for calibration of neutrino and dark matter detectors

    Science.gov (United States)

    Chepurnov, A. S.; Ionidi, V. Y.; Gromov, M. B.; Kirsanov, M. A.; Klyuyev, A. S.; Kubankin, A. S.; Oleinik, A. N.; Shchagin, A. V.; Vokhmyanina, K. A.

    2017-01-01

    The laboratory experimental setup for development of pyroelectric neutron generator for calibration of neutrino and dark matter detectors for direct search of Weakly Interacting Massive Particles (WIMP) has been developed. The setup allows providing and controlling the neutrons generation process realized during d-d nuclear fusion. It is shown that the neutrons with energy 2.45 MeV can be generated starting from a level of electric potential generated by pyroelectric crystal about 30 kV, in contrast to the typical neutron tubes which need the applied outer high voltage level about 100 kV.

  9. Infrared Detectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The end goal of this project is to develop proof-of-concept infrared detectors which can be integrated in future infrared instruments engaged in remote...

  10. Graphene-based mid-infrared room-temperature pyroelectric bolometers with ultrahigh temperature coefficient of resistance

    Science.gov (United States)

    Sassi, U.; Parret, R.; Nanot, S.; Bruna, M.; Borini, S.; De Fazio, D.; Zhao, Z.; Lidorikis, E.; Koppens, F.H.L.; Ferrari, A. C.; Colli, A.

    2017-01-01

    There is a growing number of applications demanding highly sensitive photodetectors in the mid-infrared. Thermal photodetectors, such as bolometers, have emerged as the technology of choice, because they do not need cooling. The performance of a bolometer is linked to its temperature coefficient of resistance (TCR, ∼2–4% K−1 for state-of-the-art materials). Graphene is ideally suited for optoelectronic applications, with a variety of reported photodetectors ranging from visible to THz frequencies. For the mid-infrared, graphene-based detectors with TCRs ∼4–11% K−1 have been demonstrated. Here we present an uncooled, mid-infrared photodetector, where the pyroelectric response of a LiNbO3 crystal is transduced with high gain (up to 200) into resistivity modulation for graphene. This is achieved by fabricating a floating metallic structure that concentrates the pyroelectric charge on the top-gate capacitor of the graphene channel, leading to TCRs up to 900% K−1, and the ability to resolve temperature variations down to 15 μK. PMID:28139766

  11. Bullet Design and Fabrication of Dual Mode Pyroelectric Sensor: High Sensitive Energymeter for Nd: YAG Laser and Detector for Chopped He-Ne Laser

    Directory of Open Access Journals (Sweden)

    S. SATAPATHY

    2008-05-01

    Full Text Available Pyroelectric sensor using TGS has been designed and fabricated which can be operated in laser energy meter mode as well as pyroelectric detector mode. The amplifying circuit configuration has very good signal to noise ratio, very high input impedance and low drift. The pyroelectric sensor has been tested using Q-switched Nd: YAG laser and chopped He-Ne laser. The sensitivity of pyroelectric sensor in energymeter mode is 421.7V/J and the voltage responsivity of the pyroelectric sensor is 3.27 V/W in detector mode.

  12. An infrared-driven flexible pyroelectric generator for non-contact energy harvester

    Science.gov (United States)

    Zhao, Tingting; Jiang, Weitao; Liu, Hongzhong; Niu, Dong; Li, Xin; Liu, Weihua; Li, Xuan; Chen, Bangdao; Shi, Yongsheng; Yin, Lei; Lu, Bingheng

    2016-04-01

    In recent years, energy harvesting technologies, which can scavenge many kinds of energies from our living environment to power micro/nanodevices, have attracted increasing attention. However, remote energy transmission, flexibility and electric waveform controllability remain the key challenges for wireless power supply by an energy harvester. In this paper, we design a new infrared-driven non-contact pyroelectric generator for harvesting heat energy, which avoids direct contact between the pyroelectric generator and heat source and realizes remote energy transfer exploiting the photothermal and penetrability of infrared light. The output voltage (under the input impedance of 100 MOhm) and short-circuit current of the pyroelectric generator consisting of a CNT/PVDF/CNT layer (20 mm × 5 mm × 100 μm) can be as large as 1.2 V and 9 nA, respectively, under a 1.45 W cm-2 near-infrared laser (808 nm). We also demonstrate the means by which the pyroelectric generator can modulate square waveforms with controllable periods through irradiation frequency, which is essential for signal sources and medical stimulators. The overshoot of square waveforms are in a range of 9.0%-13.1% with a rise time of 120 ms. The prepared pyroelectric generator can light a liquid crystal display (LCD) in a vacuum chamber from outside. This work paves the way for non-contact energy harvesting for some particular occasions where near-field energy control is not available.In recent years, energy harvesting technologies, which can scavenge many kinds of energies from our living environment to power micro/nanodevices, have attracted increasing attention. However, remote energy transmission, flexibility and electric waveform controllability remain the key challenges for wireless power supply by an energy harvester. In this paper, we design a new infrared-driven non-contact pyroelectric generator for harvesting heat energy, which avoids direct contact between the pyroelectric generator and heat

  13. A selective pyroelectric detector of millimeter-wave radiation with an ultrathin resonant meta-absorber

    Science.gov (United States)

    Paulish, A. G.; Kuznetsov, S. A.

    2016-11-01

    The results of experimental investigations of spectral and amplitude-frequency characteristics for a discrete wavelength-selective pyroelectric detector operating in the millimetric band are presented. The high spectral selectivity is attained due to integrating the detector with a resonant meta-absorber designed for a close-to-unity absorptivity at 140 GHz. It is demonstrated that the use of this meta-absorber provides an opportunity to construct small-sized and inexpensive multispectral polarization-sensitive systems for radiation detection in the range of millimeter and submillimeter waves.

  14. Photocapacitive MIS infrared detectors

    Science.gov (United States)

    Sher, A.; Lu, S. S.-M.; Moriarty, J. A.; Crouch, R. K.; Miller, W. E.

    1978-01-01

    A new class of room-temperature infrared detectors has been developed through use of metal-insulator-semiconductor (MIS) or metal-insulator-semiconductor-insulator-metal (MISIM) slabs. The detectors, which have been fabricated from Si, Ge and GaAs, rely for operation on the electrical capacitance variations induced by modulated incident radiation. The peak detectivity for a 1000-A Si MISIM detector is comparable to that of a conventional Si detector functioning in the photovoltaic mode. Optimization of the photocapacitive-mode detection sensitivity is discussed.

  15. Pyroelectricity Assisted Infrared-Laser Desorption Ionization (PAI-LDI) for Atmospheric Pressure Mass Spectrometry

    Science.gov (United States)

    Li, Yanyan; Ma, Xiaoxiao; Wei, Zhenwei; Gong, Xiaoyun; Yang, Chengdui; Zhang, Sichun; Zhang, Xinrong

    2015-08-01

    A new atmospheric pressure ionization method termed pyroelectricity-assisted infrared laser desorption ionization (PAI-LDI) was developed in this study. The pyroelectric material served as both sample target plate and enhancing ionization substrate, and an IR laser with wavelength of 1064 nm was employed to realize direct desorption and ionization of the analytes. The mass spectra of various compounds obtained on pyroelectric material were compared with those of other substrates. For the five standard substances tested in this work, LiNbO3 substrate produced the highest ion yield and the signal intensity was about 10 times higher than that when copper was used as substrate. For 1-adamantylamine, as low as 20 pg (132.2 fmol) was successfully detected. The active ingredient in (Compound Paracetamol and 1-Adamantylamine Hydrochloride Capsules), 1-adamantylamine, can be sensitively detected at an amount as low as 150 pg, when the medicine stock solution was diluted with urine. Monosaccharide and oligosaccharides in Allium Cepa L. juice was also successfully identified with PAI-LDI. The method did not require matrix-assisted external high voltage or other extra facility-assisted set-ups for desorption/ionization. This study suggested exciting application prospect of pyroelectric materials in matrix- and electricity-free atmospheric pressure mass spectrometry research.

  16. Materials preparation and fabrication of pyroelectric polymer/silicon MOSFET detector arrays. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bloomfield, P. [Drexel Univ., Philadelphia, PA (United States). Dept. of Materials Engineering

    1992-03-27

    The authors have delivered several 64-element linear arrays of pyroelectric elements fully integrated on silicon wafers with MOS readout devices. They have delivered detailed drawings of the linear arrays to LANL. They have processed a series of two inch wafers per submitted design. Each two inch wafer contains two 64 element arrays. After spin-coating copolymer onto the arrays, vacuum depositing the top electrodes, and polarizing the copolymer films so as to make them pyroelectrically active, each wafer was split in half. The authors developed a thicker oxide coating separating the extended gate electrode (beneath the polymer detector) from the silicon. This should reduce its parasitic capacitance and hence improve the S/N. They provided LANL three processed 64 element sensor arrays. Each array was affixed to a connector panel and selected solder pads of the common ground, the common source voltage supply connections, the 64 individual drain connections, and the 64 drain connections (for direct pyroelectric sensing response rather than the MOSFET action) were wire bonded to the connector panel solder pads. This entails (64 + 64 + 1 + 1) = 130 possible bond connections per 64 element array. This report now details the processing steps and the progress of the individual wafers as they were carried through from beginning to end.

  17. Tracking and Recognition of Multiple Human Targets Moving in a Wireless Pyroelectric Infrared Sensor Network

    Directory of Open Access Journals (Sweden)

    Ji Xiong

    2014-04-01

    Full Text Available With characteristics of low-cost and easy deployment, the distributed wireless pyroelectric infrared sensor network has attracted extensive interest, which aims to make it an alternate infrared video sensor in thermal biometric applications for tracking and identifying human targets. In these applications, effectively processing signals collected from sensors and extracting the features of different human targets has become crucial. This paper proposes the application of empirical mode decomposition and the Hilbert-Huang transform to extract features of moving human targets both in the time domain and the frequency domain. Moreover, the support vector machine is selected as the classifier. The experimental results demonstrate that by using this method the identification rates of multiple moving human targets are around 90%.

  18. Application of single-crystalline PMN-PT and PIN-PMN-PT in high-performance pyroelectric detectors.

    Science.gov (United States)

    Yu, Ping; Ji, Yadong; Neumann, Norbert; Lee, Sang-Goo; Luo, Hasou; Es-Souni, Mohammed

    2012-09-01

    The suitability for use in pyroelectric detectors of single-crystalline doped and undoped lead indium niobate-lead magnesium niobate-lead titanate was tested and compared with high-quality Mn-doped lead magnesium niobate-lead titanate and standard lithium tantalate. Pyroelectric and dielectric measurements confirmed an increased processing and operating temperature range because of the higher phase transitions of lead indium niobate-lead magnesium niobate-lead titanate. Pyroelectric coefficients of 705 to 770 μC/m(2)K were obtained with doped and undoped lead indium niobate-lead magnesium niobate-lead titanate, which are about 70% to 80% of the pyroelectric coefficient of lead magnesium niobate-lead titanate but 4 times higher than standard lithium tantalate. Manganese doping has been proved as a solution to decrease the dielectric loss of lead magnesium niobate-lead titanate and it also works well for lead indium niobate-lead magnesium niobate-lead titanate. An outstanding specific detectivity D* of about 1.1 · 10(9) cm·Hz(1/2)/W was achieved at a frequency of 2 Hz for Mn-doped lead magnesium niobate-based detectors.

  19. The flexoelectric effect associated size dependent pyroelectricity in solid dielectrics

    Directory of Open Access Journals (Sweden)

    Gang Bai

    2015-09-01

    Full Text Available A phenomenological thermodynamic theory is used to investigate the effect of strain gradient on the pyroelectric effect in centrosymmetric dielectric solids. Direct pyroelectricity can exist as external mechanical stress is applied to non-pyroelectric dielectrics with shapes such as truncated pyramids, due to elastic strain gradient induced flexoelectric polarization. Effective pyroelectric coefficient was analyzed in truncated pyramids. It is found to be controlled by size, ambient temperature, stress, and aspect ratio and depends mainly on temperature sensitivity of flexoelectric coefficient (TSFC and strain gradient of the truncated pyramids dielectric solids. These results show that the pyroelectric property of Ba0.67Sr0.33TiO3 above Tc similar to PZT and other lead-based ferroelectrics can be obtained. This feature might widely broaden the selection of materials for infrared detectors with preferable properties.

  20. The flexoelectric effect associated size dependent pyroelectricity in solid dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Gang, E-mail: baigang@njupt.edu.cn [Jiangsu Provincial Engineering Laboratory for RF Integration and Micropackaging and College of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023 (China); Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Liu, Zhiguo [Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Xie, Qiyun; Guo, Yanyan; Li, Wei [Jiangsu Provincial Engineering Laboratory for RF Integration and Micropackaging and College of Electronic Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023 (China); Yan, Xiaobing [College of Electronic and information Engineering, Hebei University, Baoding 071002 (China)

    2015-09-15

    A phenomenological thermodynamic theory is used to investigate the effect of strain gradient on the pyroelectric effect in centrosymmetric dielectric solids. Direct pyroelectricity can exist as external mechanical stress is applied to non-pyroelectric dielectrics with shapes such as truncated pyramids, due to elastic strain gradient induced flexoelectric polarization. Effective pyroelectric coefficient was analyzed in truncated pyramids. It is found to be controlled by size, ambient temperature, stress, and aspect ratio and depends mainly on temperature sensitivity of flexoelectric coefficient (TSFC) and strain gradient of the truncated pyramids dielectric solids. These results show that the pyroelectric property of Ba{sub 0.67}Sr{sub 0.33}TiO{sub 3} above T{sub c} similar to PZT and other lead-based ferroelectrics can be obtained. This feature might widely broaden the selection of materials for infrared detectors with preferable properties.

  1. Pyroelectric detectors with integrated operational amplifier for high modulation frequencies; Pyroelektrische Detektoren mit integriertem Operationsverstaerker fuer hohe Modulationsfrequenzen

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, N.; Saenze, H.; Heinze, M. [InfraTec GmbH Dresden (Germany)

    2006-02-01

    In order to use the advantages of the current mode operation a pyroelectric detector family with integrated transimpedance amplifier (TIA) was developed particularly for modulation frequencies up to the kHz range with a simplified external circuitry for new application fields, e.g. absorption spectroscopy using quantum-cascade-laser. The essential advantages of the TIA arise from the small electrical time constant {tau}{sub E} and the short-circuiting of the pyroelectric element. A flat amplitude response up to some kHz was aimed at for a sufficiently high response of 7500 V/W, appr., also at high modulation frequencies. This can be achieved through a electrical time constant of 1 ms or less and a wide bandwidth of the op amp. The article describes in detail how these demands were accomplished and which compromises had to be accepted. (orig.)

  2. FT-infrared and pyroelectric studies on calix[8]arene Langmuir-Blodgett films

    CERN Document Server

    Oliviere, P A R

    2001-01-01

    that the remaining acid groups form either facing dimers with the amine or sideways dimers between themselves. The spectra do not change with temperature. This demonstrates that the films are thermally stable. Additionally, this invariance shows that the pyroelectric activity in these films does not arise from a change in the proton transfer as has been previously postulated. Theoretical calculations undertaken predict that the source of the dipole change required for the level of pyroelectric activity seen is likely to be a change in distance between the acid and amine groups. Further observations, quantitatively examined by curve fitting techniques, show that the greater the number of proton-transferred pairs, the lower the pyroelectric coefficient. Thus, only the temperature-dependent separation of the acid and amine pairs which have not undergone proton transfer is responsible for the pyroelectric activity in these systems. Pyroelectric activity is exhibited by materials which possess a spontaneous temper...

  3. Design of Pyroelectric Infrared Alarm System%热释电红外报警系统设计

    Institute of Scientific and Technical Information of China (English)

    尚小燕; 姜旭; 武继安

    2012-01-01

    Based on the working principle of pyroelectric infrared sensor,the passive pyroelectric infrared alarm system is designed for safety of residence house to detect whether outsiders enter or not.This system was made of pyroelectric infrared sensor,Fresnel lens and monitoring circuits.Infrared signal processor BISS0001 was chosen,amplifying and filtering circuits and infrared signal processing circuit were designed on basis of the concealment of infrared,then the voice chip was utilized to simulate alarm voice for warning thieves and burglars.After many experiments,it represented that the system has sensitive response,high anti-interference ability and safe and reliable performance.%基于热释电红外传感器的工作原理,设计了一种被动式热释电红外报警器。主要用于家居安全,探测有无外人闯入。该系统由热释电红外传感器、菲涅尔透镜和监控电路组成。系统把红外线的隐蔽性很好地应用于电路中,选用了新一代红外信号处理器BISS0001,设计了放大滤波电路,红外信号处理电路,并加入语音芯片,模拟警笛声音,达到防盗目的。经多次实验,该系统反应灵敏,抗干扰能力强,安全可靠。

  4. Formation of the domain structure in CLN under the pyroelectric field induced by pulse infrared laser heating

    Energy Technology Data Exchange (ETDEWEB)

    Shur, V. Ya.; Kosobokov, M. S.; Mingaliev, E. A.; Karpov, V. R. [Institute of Natural Sciences, Ural Federal University, Ekaterinburg, 620000 (Russian Federation)

    2015-10-15

    The evolution of the self-assembled quasi-regular micro- and nanodomain structures after pulse infrared laser irradiation in congruent lithium niobate crystal was studied by in situ optical observation. Several scenarios of domain kinetics represented covering of the irradiated zone by nets of the separated domain chains and rays have been revealed. The time dependence of the total domain length was analyzed in terms of modified Kolmogorov-Avrami theory. The domain structure evolution was attributed to the action of pyroelectric field appeared during cooling. The time dependence of the spatial distribution of the pyroelectric field during pulse laser heating and subsequent cooling was calculated by finite element method. The results of computer simulation allowed us to explain the experimental results and can be used for creation of tailored domain structures thus opening the new abilities of the submicron-scale domain engineering in ferroelectrics.

  5. Formation of the domain structure in CLN under the pyroelectric field induced by pulse infrared laser heating

    Directory of Open Access Journals (Sweden)

    V. Ya. Shur

    2015-10-01

    Full Text Available The evolution of the self-assembled quasi-regular micro- and nanodomain structures after pulse infrared laser irradiation in congruent lithium niobate crystal was studied by in situ optical observation. Several scenarios of domain kinetics represented covering of the irradiated zone by nets of the separated domain chains and rays have been revealed. The time dependence of the total domain length was analyzed in terms of modified Kolmogorov-Avrami theory. The domain structure evolution was attributed to the action of pyroelectric field appeared during cooling. The time dependence of the spatial distribution of the pyroelectric field during pulse laser heating and subsequent cooling was calculated by finite element method. The results of computer simulation allowed us to explain the experimental results and can be used for creation of tailored domain structures thus opening the new abilities of the submicron-scale domain engineering in ferroelectrics.

  6. Infrared detectors for space applications

    Science.gov (United States)

    Fick, Wolfgang; Gassmann, Kai Uwe; Haas, Luis-Dieter; Haiml, Markus; Hanna, Stefan; Hübner, Dominique; Höhnemann, Holger; Nothaft, Hans-Peter; Thöt, Richard

    2013-12-01

    The motivation and intended benefits for the use of infrared (IR) detectors for space applications are highlighted. The actual status of state-of-the-art IR detectors for space applications is presented based on some of AIM's currently ongoing focal plane detector module developments covering the spectral range from the short-wavelength IR (SWIR) to the long-wavelength IR (LWIR) and very long-wavelength IR (VLWIR), where both imaging and spectroscopy applications will be addressed. In particular, the integrated detector cooler assemblies for a mid-wavelength IR (MWIR) push-broom imaging satellite mission, for the German hyperspectral satellite mission EnMAP and the IR detectors for the Sentinel 3 SLSTR will be elaborated. Additionally, dedicated detector modules for LWIR/VLWIR sounding, providing the possibility to have two different PVs driven by one ROIC, will be addressed.

  7. DUAL-BAND INFRARED DETECTORS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    As the infrared technology continues to advance, there is a growing demand for multispectral detectors for advanced IR systems with better target discrimination and identification. Both HgCdTe detectors and quantum well GaAs/AlGaAs photodetectors offer wavelength flexibility from medium wavelength to very long wavelength and multicolor capability in these regions. The main challenges facing all multicolor devices are more complicated device structtures, thicker and multilayer material growth, and more difficult device fabrication, especially when the array size gets larger and pixel size gets smaller. In the paper recent progress in development of two-color HgCdTe photodiodes and quantum well infrared photodetectors is presented.More attention is devoted to HgCdTe detectors. The two-color detector arrays are based upon an n-P-N (the capital letters mean the materials with larger bandgap energy) HgCdTe triple layer heterojunction design. Vertically stacking the two p-n junctions permits incorporation of both detectros into a single pixel. Both sequential mode and simultaneous mode detectors are fabricated. The mode of detection is determined by the fabrication process of the multilayer materials.Also the performances of stacked multicolor QWIPs detectors are presented. For multicolor arrays, QWIP's narrow band spectrum is an advantage, resulting in low spectral crosstalk. The major challenge for QWIP is developing broadband or multicolor optical coupling structures that permit efficient absorption of all required spectral bands.

  8. Infrared-transparent microstrip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, M. [Instituto de Fisica de Cantabria (IFCA), Ed. Juan Jorda, E-39005 Santander (Spain)], E-mail: Marcos.Fernandez@cern.ch; Duarte, J.; Gonzalez, J.; Heinemeyer, S.; Jaramillo, R.; Lopez, A.; Martinez, C.; Ruiz, A.; Vila, I. [Instituto de Fisica de Cantabria (IFCA), Ed. Juan Jorda, E-39005 Santander (Spain); Cabruja, E.; Lozano, M.; Pellegrini, G. [Centro Nacional de Microelectronica CNM-IMB, Campus Universidad Autonoma Barcelona, 08193 Bellaterra, Barcelona (Spain)

    2009-01-01

    The two main limiting factors in the accuracy of an optomechanical position monitoring system based on laser sources and photosensors are mechanical transfer between the monitored imaging sensors to the active particle tracking elements and non-straight propagation of the reference laser lines. Laser based alignment systems of Si trackers that use their own tracking detectors as photosensors are not affected by the first factor. Improving the transmittance of Si to infrared beams certainly minimizes the second one. Simulation of the passage of a light beam through a real microstrip detector and analysis of first measurements of samples are presented in this paper.

  9. Infrared detectors for Earth observation

    Science.gov (United States)

    Barnes, K.; Davis, R. P.; Knowles, P.; Shorrocks, N.

    2016-05-01

    IASI (Infrared Atmospheric Sounding Interferometer), developed by CNES and launched since 2006 on the Metop satellites, is established as a major source of data for atmospheric science and weather prediction. The next generation - IASI NG - is a French national contribution to the Eumetsat Polar System Second Generation on board of the Metop second generation satellites and is under development by Airbus Defence and Space for CNES. The mission aim is to achieve twice the performance of the original IASI instrument in terms of sensitivity and spectral resolution. In turn, this places very demanding requirements on the infrared detectors for the new instrument. Selex ES in Southampton has been selected for the development of the infrared detector set for the IASI-NG instruments. The wide spectral range, 3.6 to 15.5 microns, is covered in four bands, each served by a dedicated detector design, with a common 4 x 4 array format of 1.3 mm square macropixels. Three of the bands up to 8.7 microns employ photovoltaic MCT (mercury cadmium telluride) technology and the very long wave band employs photoconductive MCT, in common with the approach taken between Airbus and Selex ES for the SEVIRI instrument on Second Generation Meteosat. For the photovoltaic detectors, the MCT crystal growth of heterojunction photodiodes is by the MOVPE technique (metal organic vapour phase epitaxy). Novel approaches have been taken to hardening the photovoltaic macropixels against localised crystal defects, and integrating transimpedance amplifiers for each macropixel into a full-custom silicon read out chip, which incorporates radiation hard design.

  10. Light-Triggered Pyroelectric Nanogenerator Based on a pn-Junction for Self-Powered Near-Infrared Photosensing.

    Science.gov (United States)

    Wang, Xingfu; Dai, Yejing; Liu, Ruiyuan; He, Xu; Li, Shuti; Wang, Zhong Lin

    2017-08-22

    A nanogenerator, as a self-powered system, can operate without an external power supply for energy harvesting, signal processing, and active sensing. Here, near-infrared (NIR) photothermal triggered pyroelectric nanogenerators based on pn-junctions are demonstrated in a p-Si/n-ZnO nanowire (NW) heterostructure for self-powered NIR photosensing. The pyroelectric-polarization potential (pyro-potential) induced within wurtzite ZnO NWs couples with the built-in electric field of the pn-junction. At the moment of turning on or off the NIR illumination, external current flow is induced by the time-varying internal electric field of the pn-heterostructure, which enables a bias-free operation of the photodetectors (PDs). The NIR PD exhibits a high on/off photocurrent ratio up to 10(7) and a fast photoresponse component with a rise time of 15 μs and a fall time of 21 μs. This work provides an unconventional strategy to achieve active NIR sensing, which may find promising applications in biological imaging, optoelectronic communications, and optothermal detections.

  11. Development of an infrared detector: Quantum well infrared photodetector

    Institute of Scientific and Technical Information of China (English)

    LU Wei; LI Ling; ZHENG HongLou; XU WenLan; XIONG DaYuan

    2009-01-01

    The progress in the quantum well infrared photo-detector (QWIP) based on quantum confinement in semiconductor in recent 10 years has been reviewed. The differences between QWlP and the HgCdTe (HCT) infrared detector as well as their compensation are analyzed. The outlook for near-future trends in QWIP technologies is also presented.

  12. Development of an infrared detector: Quantum well infrared photodetector

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The progress in the quantum well infrared photo-detector (QWIP) based on quantum confinement in semiconductor in recent 10 years has been reviewed. The differences between QWIP and the HgCdTe (HCT) infrared detector as well as their compensation are analyzed. The outlook for near-future trends in QWIP technologies is also presented.

  13. 动态下红外热释电传感器的目标定位方法%New target location method based on dynamic pyroelectric infrared sensor

    Institute of Scientific and Technical Information of China (English)

    孙乔; 杨卫; 于海洋; 刘俊

    2012-01-01

    In order to improve detection sensitivity of the pyroelectric sensor and broaden the scope of traditional use of the sensor, a new applied method based on dynamic pyroelectric infrared sensor was presented in this paper, which can find the body target and coordinates. This method greatly expanded the detection range of pyroelectric infrared sensor, which could accurately determine the direction of the target according to the waveform, deduce the distance from experience. A pyroelectric infrared sensor was used as a detector in this system, innovatively use of infrared lens to replace the traditional Fresnel lenses. MCU recorded the original infrared waveform of the measurement area(if the environment keeped changeless in a long time the waveform would have a certain basic rules); once the body target walked into the measurement area, it would lead to changes of the original law, and the microcontroller would obtain direction, distance and other results according to the use of inter-frame difference method. With the traditional use of pyroelectric sensor, the method had some new feathures such as fast response, detection sensitivity, wide detection range, direction measure and distance measure. It significantly broadens the use scope of the pyroelectric sensor, and further strengthens its application in security and smart home system.%为了提高热释电传感器的探测灵敏度,拓宽其传统使用范围,提出了一种动态下热释电传感器发现人体目标并测向测距的新型使用方法.该方法大大扩展了热释电传感器的探测范围,根据波形能准确判定目标的方向,利用经验值推断出人体的目标距离.该系统采用热释电红外传感器作为探测器,创新运用红外透镜代替传统用法中的菲涅耳透镜,在步进电机的匀速带动下,单片机记录测量区域的原始红外波形(在环境基本不变且没有目标进入的情况下,波形具有一定规律且基本保持不变);目标进入测

  14. High-Quality Continuous-Wave Imaging with a 2.53 THz Optical Pumped Terahertz Laser and a Pyroelectric Detector

    Institute of Scientific and Technical Information of China (English)

    BING Pi-Bin; YAO Jian-Quan; XU De-Gang; XU Xiao-Yan; LI Zhong-Yang

    2010-01-01

    @@ A CW terahertz(THz)transmission imaging system is demonstrated and a high-quality THz image can be obtained using a pyroelectric detector.The factors that affect the imaging quality,such as the THz wavelength,spot size on the sample surface,step length of the motor,and frequency of the chopper,are theoretically and experimentally investigated.The experimental results show that the maximum resolution of the THz image can reach 0.4mm with the THz wavelength of 118.8μm.the spot size of 1.8 mm and the step length of 0.25mm.

  15. Pyroelectric characteristics of thin PbTiO3 and la-modified PbTiO3 films on platinum films for infrared sensors

    Science.gov (United States)

    Deb, K. K.; Tamagawa, T.; di, Y.; Gui, G.; Halpern, B. L.; Schmitt, J. J.

    2001-02-01

    In this work, we grew lead titanate (PbTiO3) and La-modified PbTiO3 thin films on platinized silicon (Si(100)) substrates under controlled substrate temperature and ambient by a modified jet-vapor deposition (JVD) process described in this paper. The x-ray diffraction patterns obtained from these films showed a single-phase perovskite structure. We examined locally homogeneity and thickness of these films through the comparative use of laser Raman spectroscopy. We also collected Raman and x-ray data on pure PbTiO3, as well as prepared lead zirconate titanate (PZT) (54/46), and PZT (50/50) films using the JVD process. This paper discusses the temperature variations of the pyroelectric and dielectric properties of three compositions of La-modified PbTiO3 films containing 5.2% to 15% of La, respectively, with a view toward studying the effect of La in place of Pb on these electrical properties. We detected significant pyroelectric currents on all three La-modified PbTiO3 films before performing poling treatments, and observed pyroelectric coefficeints as high as 84 nC/cm2·°C in the poled La-doped PbTiO3 films containing 5.2% La. The pyroelectric coefficient and dielectric constant varied significantly with La content. We compared the calculated figures of merit, which were based on the measured physical properties, with pure PbTiO3 as well as PZT and lead lanthanide zirconate titanate (PLZT) films. These properties just described illustrate that these films would be suitable for IR detectors.

  16. Infrared microcalorimetric spectroscopy using uncooled thermal detectors

    Energy Technology Data Exchange (ETDEWEB)

    Datskos, P.G. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics and Astronomy]|[Oak Ridge National Lab., TN (United States); Rajic, S.; Datskou, I.; Egert, C.M. [Oak Ridge National Lab., TN (United States)

    1997-10-01

    The authors have investigated a novel infrared microcalorimetric spectroscopy technique that can be used to detect the presence of trace amounts of target molecules. The chemical detection is accomplished by obtaining the infrared photothermal spectra of molecules absorbed on the surface of an uncooled thermal detector. Traditional gravimetric based chemical detectors (surface acoustic waves, quartz crystal microbalances) require highly selective coatings to achieve chemical specificity. In contrast, infrared microcalorimetric based detection requires only moderately specific coatings since the specificity is a consequence of the photothermal spectrum. They have obtained infrared photothermal spectra for trace concentrations of chemical analytes including diisopropyl methylphosphonate (DIMP), 2-mercaptoethanol and trinitrotoluene (TNT) over the wavelength region2.5 to 14.5 {micro}m. They found that in the wavelength region 2.5 to 14.5 {micro}m DIMP exhibits two strong photothermal peaks. The photothermal spectra of 2-mercaptoethanol and TNT exhibit a number of peaks in the wavelength region 2.5 to 14.5 {micro}m and the photothermal peaks for 2-mercaptoethanol are in excellent agreement with infrared absorption peaks present in its IR spectrum. The photothermal response of chemical detectors based on microcalorimetric spectroscopy has been found to vary reproducibly and sensitively as a consequence of adsorption of small number of molecules on a detector surface followed by photon irradiation and can be used for improved chemical characterization.

  17. The Design of Outdoor Passive Infrared Detector%户外被动红外探测器的设计

    Institute of Scientific and Technical Information of China (English)

    谢白玉

    2013-01-01

    This paper introduced the structure theory and application circuit of a passive-type pyroelectric infrared detector. This circuit possesses certain practical application value. The core part of this type control circuit is pyroelectric infrared sensor,which mainly uses its infrared radiation and infrared detection characteristic. This circuit uses the hidden nature of infrared to the warning systems. Thus,it realizes the function of burglar alarm and achieves the purpose of security protection.%本文主要介绍了一种被动式红外探测器的结构原理及其应用电路,此电路具有一定的实际应用价值。该类型控制电路的核心器件为热释电红外传感器,并且主要利用了它的红外辐射和红外探测的特性。这种电路把红外线的隐蔽性很好地应用于报警系统之中,从而实现了防盗报警功能,达到了安全防护之目的。

  18. Ferroelectric infrared detector and method

    Science.gov (United States)

    Lashley, Jason Charles; Opeil, Cyril P.; Smith, James Lawrence

    2010-03-30

    An apparatus and method are provided for sensing infrared radiation. The apparatus includes a sensor element that is positioned in a magnetic field during operation to ensure a .lamda. shaped relationship between specific heat and temperature adjacent the Curie temperature of the ferroelectric material comprising the sensor element. The apparatus is operated by inducing a magnetic field on the ferroelectric material to reduce surface charge on the element during its operation.

  19. Dielectric and Pyroelectric Characteristics of the Infrared Sensitive(Pb_(1-x)Sr_x)TiO_3 Ceramics

    Institute of Scientific and Technical Information of China (English)

    WANG Maoxiang; SHU Qing; MU Zhichun; JIAN Yuliang

    2009-01-01

    PST ferroelectric ceramics were fabricated successfully by a two-step method,i e first,PbTiO_3 and SrTiO_3 were sintered respectively,then mixed and sintered together.The process and characteristics of PST ferroelectric ceramics were introduced and researched.Their dielectric and pyroelectric characteristics are as follows dielectric constant 10~4 order,low dielectric loss(lower than 3.0%in the working frequency range of 1-1 000 kHz),saturation polarization intensity 10~(―1)C/m~2 order,and pyroelectric coefficient 10~(―3)C/m~2·K order.

  20. Ge photocapacitive MIS infrared detectors

    Science.gov (United States)

    Binari, S. C.; Miller, W. E.; Tsuo, Y. H.; Miller, W. E.

    1979-01-01

    An undoped Ge photocapacitive detector is reported which has peak normalized detectivities at wavelengh 1.4 microns and chopping frequencies 13-1000 Hz of 9 x 10 to the 12th, 4 x 10 to the 9th cm Hz to the 1/2th/W operating respectively at temperatures 77, 195, and 295 K. The observed temperature, spectral, and frequency response of the signal and noise are explained in terms of the measured space charge and interface state properties of the device.

  1. Two-color infrared detector

    Science.gov (United States)

    Klem, John F; Kim, Jin K

    2014-05-13

    A two-color detector includes a first absorber layer. The first absorber layer exhibits a first valence band energy characterized by a first valence band energy function. A barrier layer adjoins the first absorber layer at a first interface. The barrier layer exhibits a second valence band energy characterized by a second valence band energy function. The barrier layer also adjoins a second absorber layer at a second interface. The second absorber layer exhibits a third valence band energy characterized by a third valence band energy function. The first and second valence band energy functions are substantially functionally or physically continuous at the first interface and the second and third valence band energy functions are substantially functionally or physically continuous at the second interface.

  2. Fusion of Multiple Pyroelectric Characteristics for Human Body Identification

    Directory of Open Access Journals (Sweden)

    Wanchun Zhou

    2014-12-01

    Full Text Available Due to instability and poor identification ability of single pyroelectric infrared (PIR detector for human target identification, this paper proposes a new approach to fuse the information collected from multiple PIR sensors for human identification. Firstly, Fast Fourier Transform (FFT, Short Time Fourier Transform (STFT, Wavelet Transform (WT and Wavelet Packet Transform (WPT are adopted to extract features of the human body, which can be achieved by single PIR sensor. Then, we apply Principal Component Analysis (PCA and Support Vector Machine (SVM to reduce the characteristic dimensions and to classify the human targets, respectively. Finally, Fuzzy Comprehensive Evaluation (FCE is utilized to fuse recognition results from multiple PIR sensors to finalize human identification. The pyroelectric characteristics under scenarios with different people and/or different paths are analyzed by various experiments, and the recognition results with/without fusion procedure are also shown and compared. The experimental results demonstrate our scheme has improved efficiency for human identification.

  3. The SNAP near infrared detectors

    Energy Technology Data Exchange (ETDEWEB)

    Tarle, G.; Akerlof, C.; Aldering, G.; Amanullah, R.; Astier, P.; Barrelet, E.; Bebek, C.; Bergstrom, L.; Bercovitz, J.; Bernstein, G.; Bester, M.; Bonissent, A.; Bower, C.; Carithers, W.; Commins, E.D.; Day, C.; Deustua, S.; DiGennaro, R.; Ealet, Anne; Ellis, R.S.; Eriksson, M.; Fruchter, A.; Genat, J.-F.; Goldhaber, G.; Goobar, A.; Groom, D.; Harris, S.; Harvey, P.; Heetderks, H.; Holland, S.; Huterer, D.; Karcher, A.; Kim, A.; Kolbe, W.; Krieger, B.; Lafever, R.; Lamoureux, J.; Lampton, M.; Levi, M.E.; Levin, D.; Linder, E.; Loken, S.; Malina, R.; Massey, R.; Miguel, R.; McKay, T.; McKee, S.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Nugent, P.; Oluseyi, H.; Pain, R.; Palaio, N.; Pankow, D.; Perlmutter, S.; Pratt, R.; Prieto, E.; Refregier, A.; Rhodes, J.; Robinson, K.; Roe, N.; Sholl, M.; Schubnell, M.; Smadja, G.; Smoot, G.; Spadafora, A.; Tomasch, A.; von der Lippe, H.; Vincent, R.; Walder, J.; Wang, G.

    2002-07-29

    The SuperNova/Acceleration Probe (SNAP) will measure precisely the cosmological expansion history over both the acceleration and deceleration epochs and thereby constrain the nature of the dark energy that dominates our universe today. The SNAP focal plane contains equal areas of optical CCDs and NIR sensors and an integral field spectrograph. Having over 150 million pixels and a field-of-view of 0.34 square degrees, the SNAP NIR system will be the largest yet constructed. With sensitivity in the range 0.9-1.7 {micro}m, it will detect Type Ia supernovae between z = 1 and 1.7 and will provide follow-up precision photometry for all supernovae. HgCdTe technology, with a cut-off tuned to 1.7 {micro}m, will permit passive cooling at 140 K while maintaining noise below zodiacal levels. By dithering to remove the effects of intrapixel variations and by careful attention to other instrumental effects, we expect to control relative photometric accuracy below a few hundredths of a magnitude. Because SNAP continuously revisits the same fields we will be able to achieve outstanding statistical precision on the photometry of reference stars in these fields, allowing precise monitoring of our detectors. The capabilities of the NIR system for broadening the science reach of SNAP are discussed.

  4. Spectral responsivity calibrations of two types of pyroelectric radiometers using three different methods

    Science.gov (United States)

    Zeng, J.; Eppeldauer, G. P.; Hanssen, L. M.; Podobedov, V. B.

    2012-06-01

    Spectral responsivity calibrations of two different types of pyroelectric radiometers have been made in the infrared region up to 14 μm in power mode using three different calibration facilities at NIST. One pyroelectric radiometer is a temperature-controlled low noise-equivalent-power (NEP) single-element pyroelectric radiometer with an active area of 5 mm in diameter. The other radiometer is a prototype using the same type of pyroeletric detector with dome-input optics, which was designed to increase absorptance and to minimize spectral structures to obtain a constant spectral responsivity. Three calibration facilities at NIST were used to conduct direct and indirect responsivity calibrations tied to absolute scales in the infrared spectral regime. We report the calibration results for the single-element pyroelectric radiometer using a new Infrared Spectral Comparator Facility (IRSCF) for direct calibration. Also, a combined method using the Fourier Transform Infrared Spectrophotometry (FTIS) facility and single wavelength laser tie-points are described to calibrated standard detectors with an indirect approach. For the dome-input pyroelectric radiometer, the results obtained from another direct calibration method using a circular variable filter (CVF) spectrometer and the FTIS are also presented. The inter-comparison of different calibration methods enables us to improve the responsivity uncertainty performed by the different facilities. For both radiometers, consistent results of the spectral power responsivity have been obtained applying different methods from 1.5 μm to 14 μm with responsivity uncertainties between 1 % and 2 % (k = 2). Relevant characterization results, such as spatial uniformity, linearity, and angular dependence of responsivity, are shown. Validation of the spectral responsivity calibrations, uncertainty sources, and improvements for each method will also be discussed.

  5. 热释电探测器PZT晶片制备工艺研究%Study on Fabrication of Pyroelectric Detector PZT Wafer

    Institute of Scientific and Technical Information of China (English)

    黄江平; 王羽; 袁俊; 王学森; 郭雨航; 余瑞云

    2013-01-01

      This paper introduces the study of pyroelectric detector PZT wafer and the theory basis of choice of lead zirconate titanate(PZT)as sensitive element material. It also describes polishing and grinding theory. Factors affecting the polishing quality are analyzed in detail. The crystal surfaces polished by several different polishing liquid are analyzed by SEM, and SEM photos, surface roughness analysis and crystal surface morphology were gained. The best polishing material was determined. Through the combination of theory and practice, the pyroelectric detector wafer which could meet the technological requirements was got.%  介绍了热释电探测器PZT晶片制备工艺及选择锆钛酸铅(PZT)陶瓷材料制作敏感元的理论依据,阐述了晶片磨抛理论,对磨抛质量影响因素进行了细致分析。对比了几种抛光液对晶片表面的抛光效果,并进行了扫描电镜和表面粗糙度分析,得到了抛光后晶片表面的扫描电子显微镜(SEM)照片和晶片表面形态,确定了最佳抛光材料。通过理论和实践的结合,研制出了完全能满足器件工艺要求的热释电探测器晶片。

  6. Research on Spectral Response of an Infrared Detector%红外探测器光谱响应测量研究

    Institute of Scientific and Technical Information of China (English)

    陈亚卓; 秦玉伟

    2013-01-01

    A spectral response system for infrared detector is designed.The principle of the system is also analyzed.The spectral response experiment of the pyroelectricity detector is performed with different temperature and frequency The experiment result shows that the response of the pyroelectricity detector to infrared radiation is different,but the change trend curve of the voltage is similar.The theory of the infrared detector is thereby verified.The system has high measurement accuracy and stability,which can suppress the disturbance signal effectively and improve the signal-to-noise ratio of the system.%设计了一个红外探测器的光谱响应测试系统,并对系统原理进行了分析.对不同温度和频率情况下的热释电探测器进行光谱响应实验.实验结果表明,热释电探测器对红外辐射信号的响应不同,但电压变化曲线的趋势基本一致,从而验证了红外探测器光谱响应理论.该设计能有效抑制系统的干扰信号,提高信噪比,具有测量精度高、稳定性好的优点.

  7. Diagnosis of high-repetition-rate pulse laser with pyroelectric detector%基于热释电探测器的重频脉冲激光诊断

    Institute of Scientific and Technical Information of China (English)

    张磊; 邵碧波; 杨鹏翎; 王振宝; 闫燕

    2011-01-01

    Based on the working principles of a pyroelectric detector, the transient response of the detector to the pulse laser is researched. The model of pyroelectric detector is built, and the response in practical application is simulated according to the parameters of materials and structures. Signal process circuits which are suitable for a high-repetition-rate pulse laser are designed. Finally', a number of the repetition frequency laser radiation experiments on the pyroelectric detector are carried out. The experiments on frequency response and pulse width of the detector are completed, and the feasibility of applying the pyroelectric detector to the energy measurement of the high-repetition-rate and narrow pulse laser is verified.%摘以热释电探测器的工作原理为基础,研究了热释电探测器对重频脉冲激光的瞬态响应特性,建立了热释电探测器对单脉冲激光辐照响应的工作模型,分析了影响探测器频率特性的主要因素。根据材料和结构参数模拟计算了实际应用中的响应模型。设计了信号检测电路并对其进行计算仿事。完成了探测器的频率响应、脉宽响应等实验测量,验证了热释电探测器用于高重频、窄脉冲激光能量测量的可行性。

  8. HgCdTe barrier infrared detectors

    Science.gov (United States)

    Kopytko, M.; Rogalski, A.

    2016-05-01

    In the last decade, new strategies to achieve high-operating temperature (HOT) detectors have been proposed, including barrier structures such as nBn devices, unipolar barrier photodiodes, and multistage (cascade) infrared detectors. The ability to tune the positions of the conduction and valence band edges independently in a broken-gap type-II superlattices is especially helpful in the design of unipolar barriers. This idea has been also implemented in HgCdTe ternary material system. However, the implementation of this detector structure in HgCdTe material system is not straightforward due to the existence of a valence band discontinuity (barrier) at the absorber-barrier interface. In this paper we present status of HgCdTe barrier detectors with emphasis on technological progress in fabrication of MOCVD-grown HgCdTe barrier detectors achieved recently at the Institute of Applied Physics, Military University of Technology. Their performance is comparable with state-of-the-art of HgCdTe photodiodes. From the perspective of device fabrication their important technological advantage results from less stringent surface passivation requirements and tolerance to threading dislocations.

  9. Infrared SWAP detectors: pushing the limits

    Science.gov (United States)

    Reibel, Yann; Taalat, R.; Brunner, A.; Rubaldo, L.; Augey, T.; Kerlain, A.; Péré-Laperne, N.; Manissadjian, A.; Gravrand, O.; Castelein, P.; Destéfanis, G.

    2015-06-01

    The growing demand for compact and low consumption infrared cooled detectors is driven by different products segments. Hand Held Thermal Imagers, UAV, small gimbals are some of them. End users are requiring devices easy to use with fast cool down time, excellent portability, low acoustic noise with no trade-offs in reliability and performance. These requirements are pushing the technology developments toward constant innovations on detectors, coolers, read out circuits and proximity electronic boards. In this paper we are discussing the different figures of merit and highlighting the challenges for the different components. An update on the developments of HOT technology for most advanced pixel pitch will be presented. Very compact products are driving the developments for innovative coolers and cryogenic solutions. A low power compact architecture is a must for electronic boards to optimize the overall system power consumption. Finally a look to the future requirements for further shrink will be addressed.

  10. APPROACH TO SYNTHESIS OF PASSIVE INFRARED DETECTORS BASED ON QUASI-POINT MODEL OF QUALIFIED INTRUDER

    Directory of Open Access Journals (Sweden)

    I. V. Bilizhenko

    2017-01-01

    Full Text Available Subject of Research. The paper deals with synthesis of passive infra red (PIR detectors with enhanced detection capability of qualified intruder who uses different types of detection countermeasures: the choice of specific movement direction and disguise in infrared band. Methods. We propose an approach based on quasi-point model of qualified intruder. It includes: separation of model priority parameters, formation of partial detection patterns adapted to those parameters and multi channel signal processing. Main Results. Quasi-pointmodel of qualified intruder consisting of different fragments was suggested. Power density difference was used for model parameters estimation. Criteria were formulated for detection pattern parameters choice on the basis of model parameters. Pyroelectric sensor with nine sensitive elements was applied for increasing the signal information content. Multi-channel processing with multiple partial detection patterns was proposed optimized for detection of intruder's specific movement direction. Practical Relevance. Developed functional device diagram can be realized both by hardware and software and is applicable as one of detection channels for dual technology passive infrared and microwave detectors.

  11. Single-Band and Dual-Band Infrared Detectors

    Science.gov (United States)

    Ting, David Z. (Inventor); Gunapala, Sarath D. (Inventor); Soibel, Alexander (Inventor); Nguyen, Jean (Inventor); Khoshakhlagh, Arezou (Inventor)

    2017-01-01

    Bias-switchable dual-band infrared detectors and methods of manufacturing such detectors are provided. The infrared detectors are based on a back-to-back heterojunction diode design, where the detector structure consists of, sequentially, a top contact layer, a unipolar hole barrier layer, an absorber layer, a unipolar electron barrier, a second absorber, a second unipolar hole barrier, and a bottom contact layer. In addition, by substantially reducing the width of one of the absorber layers, a single-band infrared detector can also be formed.

  12. Gerard Kuiper and the Infrared Detector

    Science.gov (United States)

    Sears, Derek

    2013-10-01

    The life and contributions of Gerard Kuiper have been documented by Dale Cruikshank in his National Academy of Sciences biography. I will argue that particularly important in this eventful life was Kuiper's war time experiences. Kuiper's wartime role evolved as the war unfolded, but towards the end he was charged by the US military with reporting German progress with war-related technologies and the activities of scientists under Nazi control. He interviewed a great many scientists, including his own PhD mentor (Ejnar Hertzsprung), and when Kuiper was the only person available, he interviewed concentration-camp victims. He carried briefing sheets that identified the technologies being sought by the allies and the major fraction of these involved infrared equipment. He sent back to the USA boxes of documents, and large amounts of equipment, and he stressed to the military his interest in these for his own research. It seems very likely that in this way an effective PbS infrared detector, so critical to Kuiper's career and the future of planetary science, came to the USA and to Robert Cashman's laboratory at Northwestern University. As the war was winding down, Cashman and Kuiper worked together to develop a practical infrared spectrometer for astronomical use. Within months, Kuiper discovered the C02 atmospheres on Mars and Venus.

  13. 新型热释电材料及其在红外探测器中的应用%Novel pyroelectric materials and their applications in high performance infrared devices

    Institute of Scientific and Technical Information of China (English)

    刘林华; 罗豪甦; 吴啸; 赵祥永; 方家熊; 李言瑾; 邵秀梅; 景为平

    2011-01-01

    以(1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3{PMNT[(1-x)/x}为代表的大尺寸、高质量弛豫铁电单晶具有非常高的热释电系数、探测优值和较低的热扩散系数,其综合热释电性能远优于传统的热释电材料.概述了PMNT[(1-x)/x]单晶、掺锰PMNT(74/26)单晶和0.42Pb(In1/2Nb1/2)O3-0.3Pb(Mg1/3NB2/3)O3-0.28PbTiO3[PIMNT(42/30/28)]单晶的介电性能、铁电性能和热释电性能.掺杂后PMNT(74/26)单晶的介电损耗降低到0.0005,探测优值提高到40.2×10-5Pa-1/2,是目前所有三方四方相变温度(TRT)高于90℃的本征热释电材料中最高的.高居里温度PIMNT(42/30/28)单晶的TRT达到152℃,且具有较高的探测优值(10.2×10-5Pa-1/2),将在更宽温度范围内得到广泛的应用.制作了基于掺锰PMNT(74/26)单晶的单元探头,其比探测率D*达到1.07×109cmHz1/2W-1,是目前商用LiTaO3探测器的两倍,器件性能满足实用要求.%The large-size, high-quality relaxor-based ferroelectric single crystals represented by(1-x)Pb (Mg1/3Nb2/3) O3-xPbTiO3 {PMNT [(1-x)/x] } perform very high pyroelectric coefficient, detectivity figures of merit and relatively low thermal diffusivity, which makes its comprehensive pyroelectric properties far superior to the traditional pyroelectric materials. The dielectric, ferroelectric and pyroelectric properties of the PMNT [(1-x)/x], Mn-doped PMNT (74/26) and 0.42Pb(In1/2Nb1/2)O3-0.3Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 [PIMNT(42/30/28)] single crystals were overviewed. The dielectric loss of Mn-doped PMNT(74/26) crystals was declined to 0.0005, and the detectivity figures of merit was enhanced to 40.2×10-5 Pa-1/2, which was the highest value so far reported among intrinsic pyroelectric materials with TRr higher than 90 ℃. HighCurie-temperature PIMNT (42/30/28) crystals with TRT of 152 ℃, employed relatively high detectivity figures of merit (10.2×l0-5 Pa-1/2), would be widely used in a wider temperature range. The specific detectivity of infrared detector based

  14. Pyroelectric Infrared Detectors Designed%热释电红外报警器的设计

    Institute of Scientific and Technical Information of China (English)

    吕璠

    2009-01-01

    以热释电红外元件作为传感器组成的电子防盗系统,正在得到越来越广泛的应用.本文就热释电红外报警器的工作原理、安装要求和应用中存在的优缺点进行了筒述.

  15. The Design of Outdoor Passive Infrared Detector Alarm%户外被动红外探测器的设计

    Institute of Scientific and Technical Information of China (English)

    谢白玉

    2013-01-01

    This paper introduced the structure theory and application circuit of a passive-type pyroelectric infrared de-tector. This circuit has certain practical application value. The core part of this type control circuit is pyroelectric infrared sensor,which mainly uses its infrared radiation and infrared detection characteristic. This circuit applicants the hidden nature of infrared to the warning systems. Thus,it realizes the function of burglar alarm and achieves the purpose of se-curity protection.%本文主要介绍了一种被动式红外探测器的结构原理及其应用电路,此电路具有一定的实际应用价值。该类型控制电路的核心器件为热释电红外传感器,并且主要利用了它的红外辐射和红外探测的特性。这种电路把红外线的隐蔽性很好地应用于报警系统之中,从而实现了防盗报警功能,达到了安全防护之目的。

  16. Stacked Metal Silicide/Silicon Far-Infrared Detectors

    Science.gov (United States)

    Maserjian, Joseph

    1988-01-01

    Selective doping of silicon in proposed metal silicide/silicon Schottky-barrier infrared photodetector increases maximum detectable wavelength. Stacking layers to form multiple Schottky barriers increases quantum efficiency of detector. Detectors of new type enhance capabilities of far-infrared imaging arrays. Grows by molecular-beam epitaxy on silicon waferscontaining very-large-scale integrated circuits. Imaging arrays of detectors made in monolithic units with image-preprocessing circuitry.

  17. Design of Readout Circuit for Pyroelectric Detector Based on Relaxor Ferroelectric Single Crystals%弛豫铁电单晶热释电探测器读出电路的设计

    Institute of Scientific and Technical Information of China (English)

    王将; 景为平

    2011-01-01

    Relaxor-based ferroelectric single crystals, such as (1- x)Pb(Mg1/3Nb2/3 )O3-xPbTiO3 (PMN-xPT, or PMNT) single crystals, exhibit large pyroelectric response, Iow thermal diffusivity and high temperature stability.To fabricate high performance infrared detectors with relaxor-based single crystals, the related readout circuit is investigated to increase signal-to-noise ratio, and 8 × 1 CMOS readout circuit is fabricated to gain very weak current.%以(1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3(PMN-xPT或PMNT)(PMN-xPT,或PMN-PT)为代表的弛豫铁电单晶具有非常高的热释电系数、比较低的热扩散系数、比较稳定的化学性能,是一种综合性能优异的热释电材料.利用弛豫铁电单晶可以制备出高性能的红外光传感器,针对用这种新型热释电材料制成的红外光传感器,研究了相关的读出电路,探索了抑制读出电路噪声的方法,研制出了8通道的微弱电流读取电路.

  18. 热释电红外传感器及其在人员计数系统中的应用%Pyroelectric infrared sensor and its application in people counting system

    Institute of Scientific and Technical Information of China (English)

    易金桥; 黄勇; 廖红华; 谭建军; 姜胜林

    2015-01-01

    People-counting systems for image acquisition are usually complicated and expensive. In this paper, with detailed analysis of the pyroelectric effect and infrared sensor, BISS0001 integrated signal processing chip were chosen to design an amplifier circuit for the RE200B pyroelectric infrared sensor, in order to study its output waveforms under various human movement states. A people-counting system was designed, with double pyroelectric infrared sensors as the signal acquisition unit and a Cortex-M3 microcontroller as the control core, and its main algorithms were researched. The experimental results demonstrate that different body movement states can be accurately characterized using the output waveforms of the RE200B pyroelectric infrared sensor and the movement directions can be precisely distinguished by the people-counting system based on double pyroelectric infrared sensors designed in this paper. Furthermore, the system realizes real-time counting, and can be applied to a wide range of areas including human body detection and counting.%针对图像采集人员计数系统复杂、价格昂贵等缺点,在分析热释电效应以及红外传感的基础上,采用BISS0001型信号处理专用集成芯片设计了基于RE200B热释电红外传感器的放大电路,研究其在不同人体运动状态下的输出波形;设计了以双热释电红外传感器为信号采集单元,以Cortex-M3单片机为控制核心的人员计数系统,并研究其主要算法。实验结果表明,RE200B型热释电红外传感器的输出波形能够准确表征人体的不同运动状态,基于双热释电红外传感器的人员计数系统能准确分辨人体的运动方向,并实时计数,可广泛应用于人体探测和人员计数等领域。

  19. Research of High Sensitivity Uncooled Infrared Detector Array

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Pingchuan [Huazhong University of Science and Technology, Wuhan 430074 (China); Zhang, Bo, E-mail: redmoon123456@126.com, E-mail: lhzyzb@126.com [Luohe Vocational Technology College, Luohe 462002 (China)

    2011-02-01

    The infrared thermal imaging technology has been widely used in military and civilian fields and the field of the infrared detection and infrared thermal imaging technology has been of concern for a long time. On infrared thermal imaging, its core components for the infrared focal plane arrays, how to develop a high sensitivity of the multi-focal plane infrared detector is a key issue. Although the Common focal plane array of quantum has high sensitivity, but it requires low temperature cooling work environment and led to complexity and high cost, difficult to compact. Conventional uncooled infrared focal plane array is contrast to the quantum focal plane arrays. Therefore, this article preceded by the uncooled infrared detector array to improve the wide temperature sensitivity in examining the feasibility PMN composite film, materials composition, structure design and preparation process technology.

  20. Multi-spectral black meta-infrared detectors (Conference Presentation)

    Science.gov (United States)

    Krishna, Sanjay

    2016-09-01

    There is an increased emphasis on obtaining imaging systems with on-demand spectro-polarimetric information at the pixel level. Meta-infrared detectors in which infrared detectors are combined with metamaterials are a promising way to realize this. The infrared region is appealing due to the low metallic loss, large penetration depth of the localized field and the larger feature sizes compared to the visible region. I will discuss approaches to realize multispectral detectors including our recent work on double metal meta-material design combined with Type II superlattices that have demonstrated enhanced quantum efficiency (collaboration with Padilla group at Duke University).

  1. Using quantum filters as edge detectors in infrared images

    Science.gov (United States)

    Bolaños Marín, Daniela

    2014-06-01

    Some new filters inspired in quantum models are used as edge detectors in infrared images. In this case, Bessel, Hermite and Morse filters will be applied to detect edges and fibrillar structures in infrared images. The edge detectors will be built by the Laplacian of the mentioned quantum filters. Furthermore, using curvature operators, curvature detectors and amplifiers of contrast will be constructed to analyze infrared images. The quantum filter prototyping will be done using computer algebra software, specifically Maple and its package, ImageTools. The quantum filters will be applied to infrared images using the technique of convolutions and blurred derivatives. It is expected that designed quantum filters will be useful for analysis and processing of infrared images. As future investigations, we propose to design plugins with the quantum filters that can be incorporated into the program ImageJ, which will facilitate the use of the quantum filters for the infrared image processing.

  2. Complementary Barrier Infrared Detector (CBIRD) with Double Tunnel Junction Contact and Quantum Dot Barrier Infrared Detector (QD-BIRD)

    Science.gov (United States)

    Ting, David Z.-Y; Soibel, Alexander; Khoshakhlagh, Arezou; Keo, Sam A.; Nguyen, Jean; Hoglund, Linda; Mumolo, Jason M.; Liu, John K.; Rafol, Sir B.; Hill, Cory J.; Gunapala, Sarath D.

    2012-01-01

    The InAs/GaSb type-II superlattice based complementary barrier infrared detector (CBIRD) has already demonstrated very good performance in long-wavelength infrared (LWIR) detection. In this work, we describe results on a modified CBIRD device that incorporates a double tunnel junction contact designed for robust device and focal plane array processing. The new device also exhibited reduced turn-on voltage. We also report results on the quantum dot barrier infrared detector (QD-BIRD). By incorporating self-assembled InSb quantum dots into the InAsSb absorber of the standard nBn detector structure, the QD-BIRD extend the detector cutoff wavelength from approximately 4.2 micrometers to 6 micrometers, allowing the coverage of the mid-wavelength infrared (MWIR) transmission window. The device has been observed to show infrared response at 225 K.

  3. Complementary Barrier Infrared Detector (CBIRD) with Double Tunnel Junction Contact and Quantum Dot Barrier Infrared Detector (QD-BIRD)

    Science.gov (United States)

    Ting, David Z.-Y; Soibel, Alexander; Khoshakhlagh, Arezou; Keo, Sam A.; Nguyen, Jean; Hoglund, Linda; Mumolo, Jason M.; Liu, John K.; Rafol, Sir B.; Hill, Cory J.; hide

    2012-01-01

    The InAs/GaSb type-II superlattice based complementary barrier infrared detector (CBIRD) has already demonstrated very good performance in long-wavelength infrared (LWIR) detection. In this work, we describe results on a modified CBIRD device that incorporates a double tunnel junction contact designed for robust device and focal plane array processing. The new device also exhibited reduced turn-on voltage. We also report results on the quantum dot barrier infrared detector (QD-BIRD). By incorporating self-assembled InSb quantum dots into the InAsSb absorber of the standard nBn detector structure, the QD-BIRD extend the detector cutoff wavelength from approximately 4.2 micrometers to 6 micrometers, allowing the coverage of the mid-wavelength infrared (MWIR) transmission window. The device has been observed to show infrared response at 225 K.

  4. Electronic detection of ultra-heavy nuclei by pyroelectric materials

    Science.gov (United States)

    Simpson, J. A.; Tuzzolino, A. J.

    1983-01-01

    A recent prediction by the authors that pyroelectric materials may be capable of detecting ultra-heavy nuclei has been confirmed. Charge pulse signals from pyroelectric crystals of lithium tantalate exposed to Au ions and a pulsed beam of Ni-58 ions, and from pyroelectric films of polyvinylidene fluoride exposed to a pulsed beam of Ni-58 ions, have been measured using pulse electronics with time constants in the microsecond range. These studies show that pyroelectric materials, in general, are capable of detecting incident nuclei having very high mass and charge. In particular, pyroelectric polymers, such as polyvinylidene fluoride, are readily available as inexpensive flexible films. This new class of charged particle detector could eventually find applications in large-area experiments for detection and trajectory determination of low-energy, ultra-heavy nuclei.

  5. Enhancement of pyroelectric signal by continuous ultraviolet illumination of epitaxial Pb(Zr{sub 0.2}Ti{sub 0.8})O{sub 3} films

    Energy Technology Data Exchange (ETDEWEB)

    Pintilie, L.; Iuga, A. [National Institute of Materials Physics, Atomistilor 105bis, Magurele, Ilfov 077125 (Romania); Botea, M. [National Institute of Materials Physics, Atomistilor 105bis, Magurele, Ilfov 077125 (Romania); Faculty of Physics, University of Bucharest, Magurele 077125 (Romania)

    2014-09-29

    The pyroelectric signal generated by an epitaxial Pb(Zr{sub 0.2}Ti{sub 0.8})O{sub 3} film can be enhanced by continuous illumination with ultraviolet (UV) light. The measured signal increases more than 2 times at low modulation frequencies of the incident infrared (IR) radiation (∼10 Hz) and at wavelengths where the short-circuit photocurrent presents the maximum value (∼280–300 nm). The tentative explanation is that the changes in polarization induced by the temperature variation under modulated IR illumination are generating a variable internal electric field, able to collect the photogenerated carriers produced under continuous UV illumination leading to an additional signal in phase with the pyroelectric one. This finding could be exploited for designing pyroelectric detectors with enhanced characteristics by combining both UV and IR responses.

  6. 热释电红外传感器在新型弹药引信中的应用%Application of Pyroelectric Infrared Sensor in New Ammunition Fuze

    Institute of Scientific and Technical Information of China (English)

    平子鹏; 赵洋

    2016-01-01

    The target detection and recognition of the fuze is an important part of the new intelligent ammunition .Com‐bined with the current target detection and recognition technology ,a method of target detection and identification is presented based on the pyroelectric infrared sensor .On the basis of the working principle of pyroelectric infrared sensor ,the infrared characteristics of the human body are analyzed and the experimental simulation is carried out .The results show that the tar‐get detection and recognition based on pyroelectric infrared sensor is feasible ,which has a key role in improving the opera‐tional effectiveness of weapon system ,enhancing the conventional deterrence and combat capability .%引信的目标探测与识别是新型智能弹药系统的重要组成部分,结合当今目标探测识别技术,给出了一种基于热释电红外传感器的引信探测与识别方法。文章在阐述热释电红外传感器工作原理的基础上,分析人体目标的红外特性并进行实验仿真。结果表明,基于热释电红外传感器的引信目标探测与识别是可行的,对提高武器系统作战效能,增强常规威慑和实战能力具有关键作用。

  7. Heterojunction and superlattice detectors for infrared to ultraviolet

    Science.gov (United States)

    Perera, A. G. U.

    2016-07-01

    The interest in Infrared and Ultraviolet detectors has increased immensely due to the emergence of important applications over a wide range of activities. Detectors based on free carrier absorption known as Hetero-junction Interfacial Workfunction Internal Photoemission (HEIWIP) detectors and variations of these heterojunction structures to be used as intervalence band detectors for a wide wavelength region are presented. Although this internal photoemission concept is valid for all semiconductor materials systems, using a well-studied III-V system of GaAs/AlxGa1-x As to cover a wide wavelength range from UV to far-infrared (THz) is an important development in detector technology. Using the intervalence band (heavy hole, light hole and split off) transitions for high operating temperature detection of mid Infrared radiation is also discussed. A promising new way to extend the detection wavelength threshold beyond the standard threshold connected with the energy gap in a GaAs/AlxGa1-x As system is also presented. Superlattice detector technology, which is another promising detector architecture, can be optimized using both Type I and Type II heterostructures. Here the focus will be on Type II Strained Layer (T2SL) Superlattice detectors. T2SL Superlattices based on InAs/(In,GA)Sb have made significant improvements demonstrating focal plane arrays operating around 80 K and with multiple band detection capability. A novel spectroscopic method to evaluate the band offsets of both heterojunction and superlattice detectors is also discussed.

  8. Infra-red signature neutron detector

    Science.gov (United States)

    Bell, Zane William [Oak Ridge, TN; Boatner, Lynn Allen [Oak Ridge, TN

    2009-10-13

    A method of detecting an activator, the method including impinging with an activator a receptor material that includes a photoluminescent material that generates infrared radiation and generation a by-product of a nuclear reaction due to the activator impinging the receptor material. The method further includes generating light from the by-product via the Cherenkov effect, wherein the light activates the photoluminescent material so as to generate the infrared radiation. Identifying a characteristic of the activator based on the infrared radiation.

  9. Application of LiTaO3 pyroelectric crystal for pulsed neutron detection

    Science.gov (United States)

    Liang, W. F.; Lu, Y.; Wu, J.; Gao, H.; Li, M.

    2016-08-01

    The feasibility of a LiTaO3 pyroelectric crystal for pulsed neutron detection has been studied. The detector consists of a slice of electroded Z-cut LiTaO3 pyroelectric crystal, and no additional neutron converter is required owing to the Li contained in the crystal. The slight temperature increase caused by neutron radiation will lead to the release of bound charges and will give rise to a pyroelectric signal. The response of it has been studied both theoretically and experimentally. Our preliminary experiment on the CFBR-II reactor suggests that the LiTaO3 pyroelectric detector is promising for high intensity neutron - pulse measurement.

  10. Plasmonic lens enhanced mid-infrared quantum cascade detector

    Energy Technology Data Exchange (ETDEWEB)

    Harrer, Andreas, E-mail: andreas.harrer@tuwien.ac.at; Schwarz, Benedikt; Gansch, Roman; Reininger, Peter; Detz, Hermann; Zederbauer, Tobias; Andrews, Aaron Maxwell; Schrenk, Werner; Strasser, Gottfried [Institute for Solid State Electronics and Center for Micro- and Nanostructures, Vienna University of Technology, 1040 Vienna (Austria)

    2014-10-27

    We demonstrate monolithic integrated quantum cascade detectors enhanced by plasmonic lenses. Surface normal incident mid-infrared radiation is coupled to surface plasmon polaritons guided to and detected by the active region of the detector. The lens extends the optical effective active area of the device up to a 5 times larger area than for standard mesa detectors or pixel devices while the electrical active region stays the same. The extended optical area increases the absorption efficiency of the presented device as well as the room temperature performance while it offers a flexible platform for various detector geometries. A photocurrent response increase at room temperature up to a factor of 6 was observed.

  11. Using a CO2 laser for PIR-detector spoofing

    NARCIS (Netherlands)

    Schleijpen, R.; Putten, F.J.M. van

    2016-01-01

    This paper presents experimental work on the use of a CO2 laser for triggering of PIR sensors. Pyro-electric InfraRed sensors are often used as motion detectors for detection of moving persons or objects that are warmer than their environment. Apart from uses in the civilian domain, also

  12. Precision Calibration of Infrared Synchrotron Radiation Detectors

    CERN Document Server

    Maltsev, A A; Maslova, M V

    2003-01-01

    The technique of calibration of synchrotron radiation precision detectors on a tungsten source based on similarity (close similarity) of character of spectral distributions of synchrotron and thermal radiations is given. The characteristics of various commonly used lamps, used as "standard" ones, are given. The errors of measurements are analyzed. The detectors are intended for absolute measurements of the number of electrons in a ring-shaped bunch.

  13. Multi-Object Tracking Scheme with Pyroelectric Infrared Sensor and Video Camera Coordination%融合热释电红外传感器与视频监控器的多目标跟踪算法

    Institute of Scientific and Technical Information of China (English)

    李方敏; 姜娜; 熊迹; 张景源

    2014-01-01

    现有基于热释电红外传感器的多目标跟踪系统在目标之间距离较近或者轨迹相交的情况下存在着误差较大的缺点。针对此缺点,提出了一种新型的基于热释电红外传感器与视频监测器协同工作的多目标跟踪方案。该方案可以充分利用两种传感器的优势,弥补在目标跟踪中的不足。算法采用最小二乘法利用热释电信息进行定位,并通过从图像或热释电传感器信号的幅频特性中提取特征信息来校正联合概率数据关联算法的关联矩阵,有效避免了错误关联。实验表明,该方案在多目标交叉情况下跟踪误差仅为其它算法的八分之一到四分之一。%The error tends to be significant in many existing pyroelectric infrared sensor based multi-object tracking systems when the measured objects get close to each other or their trajectories have intersections .To solve this problem ,we proposed a mul-ti-object tracking scheme by having pyroelectric infrared sensors and video cameras work cooperatively .This scheme takes the ad-vantages of both kinds of sensors ,which help to improve the performance compared to those using any kind of such sensors .In the proposed scheme ,we first achieve coarse positioning using least square method with data collected by pyroelectric infrared sensors , and then we correct the incidence matrix in joint probabilistic data association with features extracted from the images or the fre -quency responses of pyroelectric sensors .The coarse positioning is further filtered by joint probabilistic data association algorithm to obtain the final fine result .Such a method prevents false association effectively .Experimental results show that the tracking error of the proposed scheme in multi-object crossover scenario reduces to a quarter ,even to one eighth of the errors that exist in the com-pared schemes .

  14. High performance infrared fast cooled detectors for missile applications

    Science.gov (United States)

    Reibel, Yann; Espuno, Laurent; Taalat, Rachid; Sultan, Ahmad; Cassaigne, Pierre; Matallah, Noura

    2016-05-01

    SOFRADIR was selected in the late 90's for the production of 320×256 MW detectors for major European missile programs. This experience has established our company as a key player in the field of missile programs. SOFRADIR has since developed a vast portfolio of lightweight, compact and high performance JT-based solutions for missiles. ALTAN is a 384x288 Mid Wave infrared detector with 15μm pixel pitch, and is offered in a miniature ultra-fast Joule- Thomson cooled Dewar. Since Sofradir offers both Indium Antimonide (InSb) and Mercury Cadmium Telluride technologies (MCT), we are able to deliver the detectors best suited to customers' needs. In this paper we are discussing different figures of merit for very compact and innovative JT-cooled detectors and are highlighting the challenges for infrared detection technologies.

  15. Mercury Cadmium Telluride Photoconductive Long Wave Infrared Linear Array Detectors

    Directory of Open Access Journals (Sweden)

    Risal Singh

    2003-07-01

    Full Text Available Mercury cadmium telluride (Hg1-x, CdxTe (MCT photoconductive long wave infrared linear arrays are still in demand due to several advantages. The linear array technology is well established, easier, economical and is quite relevant to thermal imaging even today. The scan thermal imaging systems based on this technology offer wider field of view coverage and capacity for higher resolution in the scan direction relative to staring systems that use expensive and yet to mature focal plane array detector technology. A critical review on photoconductive n-Hg1-x CdxTe linear array detector technology for the long wave infrared range has been presented. The emphasis lies on detector design and processing technology. The critical issues of diffusion and drift effects, Hi-Lo and heterostructure blocking contacts, surface passivation, and other related aspects have been considered from the detector design angle. The device processing technology aspects are of vital importance

  16. Materials processing threshold report. 1: Semiconductor crystals for infrared detectors

    Science.gov (United States)

    Sager, E. V.; Thompson, T. R.; Nagler, R. G.

    1980-01-01

    An extensive search was performed of the open literature pertaining to infrared detectors to determine what constitutes a good detector and in what way performance is limited by specific material properties. Interviews were conducted with a number of experts in the field to assess their perceptions of the state of the art and of the utility of zero-gravity processing. Based on this information base and on a review of NASA programs in crystal growth and infrared sensors, NASA program goals were reassessed and suggestions are presented as to possible joint and divergent efforts between NASA and DOD.

  17. Infrared Superconducting Single-Photon Detectors

    Science.gov (United States)

    2012-10-05

    group realized small microstrip devices, the next iteration of which may narrow the line width to below 100 nm, entering the single-photon detection...and will explore superconducting detectors with integrated waveguide circuits and novel deposition techniques. 15. SUBJECT...world record quantum cryptography demonstrations [9] and operation of quantum waveguide circuits at telecom wavelengths [10]. Beyond the quantum

  18. Design and Research on Amplifier Circuit for Pyroelectric Infrared Sensor%热释电红外传感器前置放大电路设计与研究

    Institute of Scientific and Technical Information of China (English)

    滕飞扬; 陈连坤

    2012-01-01

    介绍热释电红外传感器的工作原理和性能,分析热释电红外传感器的信号输出特性,设计基于此类传感器的前置滤波放大电路.并使用单片机进行经过电路放大后的脉冲信号的分析,完成对人体运动的检测。使用Alfium Designer6.9对前置滤波放大电路进行软件仿真,以验证该放大电路的有效性和可靠性。%Introduces the working principle and performance of pyroelectric infrared sensor, and analyses the characteristics of pyroelectric infrared sensor signal output, then designs an preamplifier based on this type of sensor, and uses the microcontroller for analysis of the amplified signal to finish the detection of human motion. Uses Ahium Designer 6.9 to simulate the preamplifier, verifies the validities and reliability of the preamplifier.

  19. Mid-Infrared Tunable Resonant Cavity Enhanced Detectors

    Directory of Open Access Journals (Sweden)

    Hans Zogg

    2008-09-01

    Full Text Available Mid-infrared detectors that are sensitive only in a tunable narrow spectral band are presented. They are based on the Resonant Cavity Enhanced Detector (RCED principle and employing a thin active region using IV-VI narrow gap semiconductor layers. A Fabry-Pérot cavity is formed by two mirrors. The active layer is grown onto one mirror, while the second mirror can be displaced. This changes the cavity length thus shifting the resonances where the detector is sensitive. Using electrostatically actuated MEMS micromirrors, a very compact tunable detector system has been fabricated. Mirror movements of more than 3 μm at 30V are obtained. With these mirrors, detectors with a wavelength tuning range of about 0.7 μm have been realized. Single detectors can be used in mid-infrared micro spectrometers, while a detector arrangement in an array makes it possible to realize Adaptive Focal Plane Arrays (AFPA.

  20. Silicon-Germanium Alloys for Infrared Detectors.

    Science.gov (United States)

    1980-04-01

    crystals, aiming at improved crystallinity and higher resistivity and to extend the Czochralski growth method to indium-doped Si-Ge alloys. Our intention...of the disappointingly high boron concentrations achieved in Czochralski growth, we decided to explore a crucible-free method for preparing Si-Ge...material was not high enough to allow an adequately long depletion region in a p-i-n detector. It does not appear that any Czochralski -type growth method

  1. Center for Research on Infrared Detectors (CENTROID)

    Science.gov (United States)

    2006-09-30

    Average carper energy in a bound-to-continuum detector for va:rious val- ue~ of tow-field capture tillllt . Figure 5. Results of Monte Carlo studies...Orlando and Santa Barbara Focal Plane in the realization of QDIP-based IR cameras. We have fabricated and shipped 320x256 QDIP arrays to them for...International Science Center HRL Laboratories Texas Instruments/DRS Technologies EPIR Limited Lockheed Martin Santa Barbara Focalplane BAE Systems AFRL

  2. Pyroelectric infrared alarm system based on human gait recognition%基于人体步态识别的热释电红外传感报警系统

    Institute of Scientific and Technical Information of China (English)

    张涛; 钟舜聪

    2011-01-01

    In order to solve the problem of difficult detecting the motionless human body using pyroelectric infrared (PIR) sensor, a passive PIR alarm system based on human gait recognition was investigated to enhance the intelligence of the system and to reduce the false alarm rate. As the detector, PIR sensor was employed in the system for non-contact monitoring the human body within a certain distance. The PIR signal was filtered, amplified, and then converted to a digital signal by an analog-to-digital converter. Consequently, the digital signal was sent to a microcomputer ( MCU ) for processing. The human body movement characteristics were analyzed to achieve accurate security alarm purpose. The experimental results demonstrate the stable performance, high sensitivity and low false alarm rate of the developed PIR alarm system, therefore, it can be recommended for the applications in security system of home, shopping center, and warehouse.%针对热释电红外传感器对运动后静止的人体无法感应的缺点,设计了一种基于人体步态识别的热释电红外报警系统,大大提高了系统感知智能度,减少了报警的误报率.该系统利用热释电红外传感器(PIR)作为探头,将感测到人体的红外信息转换成电压信号,通过滤波、放大等信号调理以及经过数据采集后,将信号传递给单片机处理,结合人体运动特征进行步态识别,从而实现智能报警,达到安全防护的目的.研究结果表明,基于人体步态识别的热释电红外报警系统具有性能稳定、灵敏度高、误报率低等优点,适合各种安全报警的场合,具有广泛的应用前景.

  3. Field guide to infrared systems, detectors, and FPAs

    CERN Document Server

    Daniels, Arnold

    2011-01-01

    This second edition is written to clarify and summarize the theoretical principles of infrared technology. It is intended as a reference for the practicing engineer and/or scientist who requires effective practical information to design, build, and/or test infrared equipment in a wide variety of applications. This Field Guide combines numerous engineering disciplines necessary for the development of an infrared system. It describes the basic elements involving image formation and image quality, radiometry and flux transfer, and explains the figures of merit involving detector performance. It c

  4. Challenges of small-pixel infrared detectors: a review

    Science.gov (United States)

    Rogalski, A.; Martyniuk, P.; Kopytko, M.

    2016-04-01

    In the last two decades, several new concepts for improving the performance of infrared detectors have been proposed. These new concepts particularly address the drive towards the so-called high operating temperature focal plane arrays (FPAs), aiming to increase detector operating temperatures, and as a consequence reduce the cost of infrared systems. In imaging systems with the above megapixel formats, pixel dimension plays a crucial role in determining critical system attributes such as system size, weight and power consumption (SWaP). The advent of smaller pixels has also resulted in the superior spatial and temperature resolution of these systems. Optimum pixel dimensions are limited by diffraction effects from the aperture, and are in turn wavelength-dependent. In this paper, the key challenges in realizing optimum pixel dimensions in FPA design including dark current, pixel hybridization, pixel delineation, and unit cell readout capacity are outlined to achieve a sufficiently adequate modulation transfer function for the ultra-small pitches involved. Both photon and thermal detectors have been considered. Concerning infrared photon detectors, the trade-offs between two types of competing technology—HgCdTe material systems and III-V materials (mainly barrier detectors)—have been investigated.

  5. Improved Ambient Pressure Pyroelectric Ion Source

    Science.gov (United States)

    Beegle, Luther W.; Kim, Hugh I.; Kanik, Isik; Ryu, Ernest K.; Beckett, Brett

    2011-01-01

    The detection of volatile vapors of unknown species in a complex field environment is required in many different applications. Mass spectroscopic techniques require subsystems including an ionization unit and sample transport mechanism. All of these subsystems must have low mass, small volume, low power, and be rugged. A volatile molecular detector, an ambient pressure pyroelectric ion source (APPIS) that met these requirements, was recently reported by Caltech researchers to be used in in situ environments.

  6. Development of Kinetic Inductance Detectors for Far-Infrared Spectroscopy

    Science.gov (United States)

    Barlis, Alyssa; Aguirre, James E.; Stevenson, Thomas

    2016-01-01

    An instrument with high sensitivity and spectral resolution at far-infrared wavelengths could contribute significantly to several currently unanswered questions in astrophysics. Here, we describe a detector system suitable for a spectroscopic experiment at far-infrared wavelengths using kinetic inductance detectors (KIDs). KIDs have the potential to achieve high sensitivity and low noise levels. Specifically, the approach we take uses lumped-element KIDs, which consist of separate capacitive and inductive elements combined to form a microresonator. The inductive element serves as a direct radiation absorber. We describe the design considerations, fabrication process, and readout scheme for a prototype LEKID array of 1600 pixels, along with results from a prototype detector array.

  7. 基于单片机热释电红外安防报警器的设计%Design of Pyroelectric Infrared Security Alarm Based Single-Chip Microcomputer

    Institute of Scientific and Technical Information of China (English)

    赵巧妮

    2016-01-01

    热释电红外防盗报警器是利用红外传感器技术来自动探测发生在布防监测区域内的异常人员的入侵行为,并及时产生声光报警信号,提示主人及时处理异常情况,避免危险情况发生,维护社会和家庭人员、财产的安全。%Pyroelectric infrared burglar alarm, by using infrared sensor technology, can automatically detect abnormalities by armed persons in the event of intrusion monitoring area, and timely produce sound and light alarms to notify the owner to respond to avoid theft, snatches, or sabotage, in order to maintain security of social and family members, and of property.

  8. Recent developments in materials and detectors for the infrared; Proceedings of the Meeting, Cannes, France, November 25, 26, 1985

    Science.gov (United States)

    Morten, F. D. (Editor); Seeley, John S. (Editor)

    1986-01-01

    The present conference on advancements in IR-sensitive materials and detector technologies employing them gives attention to thermal detectors, focal plane array processing detectors, novel detector designs, general properties of IR optics materials, and preparation methods for such materials. Specific topics encompass the fabrication of InSb MIS structures prepared by photochemical vapor deposition, IR heterodyne detectors employing cadmium mercury telluride, low microphony pyroelectric arrays, IR detection based on minority carrier extrusion, longwave reststrahl in IR crystals, and molecular beam techniques for optical thin film fabrication.

  9. Type-ii binary superlattices for infrared detector

    Energy Technology Data Exchange (ETDEWEB)

    Razeghi, M.; Mohseni, H. [Northwestern Univ., Evanston (United States); Brown, G. J. [WPAFB, Colombus (United States)

    2001-12-01

    III-V quantum wells and superlattices based on InAs/GaSb/AlSb, and related compounds have attracted many attentions due to their unique band alignments and physical properties. Recently, novel electronic and optoelectronic heterostructures have been proposed from this material system for hundred gigahertz logic circuits, terahertz transistors. RTDs, infrared lasers, and infrared detectors. In this paper we will describe the ongoing research at the Center for Quantum Devices to develop the theory, modeling, growth, characterization, and device fabrication techniques for this material system. We have demonstarted the first uncooled infrared detectors from type-II superlattices. The measured detectivity is more than 1 x 10{sup 8} cmHz{sup 1/2}/W at 10.6 {mu}m at room temperature which is higher than the commercially available uncooled photon detectors at similar wavelength. In paralle, we have demonstraed the first high-performance p-i-n type-II photodiode in the very long wavelength infrared (VLWIR) range operating at T=80K. The devices with cutoff wavelength of 16 mm showed a responsivity of 3.5 A/W at 80 K leading to a detectivity of {approx}1.51x10{sup 10} cmHz{sup 1/2}/W. Similar devices with cutoff wavelengths up to 25 {mu}m was demonstrated at 80 K. To enhance this technology further, we plan to move from quantum wells to quantum wire and quantum dots.

  10. Performance overview of the Euclid infrared focal plane detector subsystems

    Science.gov (United States)

    Waczynski, A.; Barbier, R.; Cagiano, S.; Chen, J.; Cheung, S.; Cho, H.; Cillis, A.; Clémens, J.-C.; Dawson, O.; Delo, G.; Farris, M.; Feizi, A.; Foltz, R.; Hickey, M.; Holmes, W.; Hwang, T.; Israelsson, U.; Jhabvala, M.; Kahle, D.; Kan, Em.; Kan, Er.; Loose, M.; Lotkin, G.; Miko, L.; Nguyen, L.; Piquette, E.; Powers, T.; Pravdo, S.; Runkle, A.; Seiffert, M.; Strada, P.; Tucker, C.; Turck, K.; Wang, F.; Weber, C.; Williams, J.

    2016-07-01

    In support of the European space agency (ESA) Euclid mission, NASA is responsible for the evaluation of the H2RG mercury cadmium telluride (MCT) detectors and electronics assemblies fabricated by Teledyne imaging systems. The detector evaluation is performed in the detector characterization laboratory (DCL) at the NASA Goddard space flight center (GSFC) in close collaboration with engineers and scientists from the jet propulsion laboratory (JPL) and the Euclid project. The Euclid near infrared spectrometer and imaging photometer (NISP) will perform large area optical and spectroscopic sky surveys in the 0.9-2.02 μm infrared (IR) region. The NISP instrument will contain sixteen detector arrays each coupled to a Teledyne SIDECAR application specific integrated circuit (ASIC). The focal plane will operate at 100K and the SIDECAR ASIC will be in close proximity operating at a slightly higher temperature of 137K. This paper will describe the test configuration, performance tests and results of the latest engineering run, also known as pilot run 3 (PR3), consisting of four H2RG detectors operating simultaneously. Performance data will be presented on; noise, spectral quantum efficiency, dark current, persistence, pixel yield, pixel to pixel uniformity, linearity, inter pixel crosstalk, full well and dynamic range, power dissipation, thermal response and unit cell input sensitivity.

  11. LHI878热释电红外传感器的体温检测系统设计%Design of temperature detection system base on LH878 pyroelectric infrared sensor

    Institute of Scientific and Technical Information of China (English)

    赵春华; 许云涛; 宁春玉

    2013-01-01

      设计一种以ATmage32单片机为核心的热释电红外体温测量系统.利用热释电红外传感器,设计一个非接触式的语音播报体温测量系统.采用热释电红外传感器来提取人体温度信号,同时由DS18B20测量环境温度信号,进行温度补偿减少测量误差.将提取的温度信号经过模拟处理后由AVR单片机控制实现对人体温度值的转换及处理,将得到的温度值送入LCD显示及语音播报.同时还加入了时钟功能和超温报警功能,使设计更具实用性.该体温测量系统测量范围为35~42益,测量时间小于1 s.该温度检测系统具有使用方便、灵活性好、可靠性高等优点,具有一定的推广应用价值.%A kind of pyroelectric infrared temperature measurement system was designed, which core was the ATmage32 SCM. It was a non-contact and voice prompt temperature measurement system by using pyroelectric infrared sensor. It used the pyroelectric infrared sensor to extrat the temperature of the human body and the DS18B20 to measure the environmental temperature, which could achieve the temperature compensation to reduce the measurement error. It could be controlled to realize the temperature convertion and processing, and sent the temperature value to the LCD to display and the voice prompt by the AVR SCM. Simultaneously, it was added the clock function and overtemperature alarm function to make the design more practical. The temperature measurement range was from 35-42℃. The measurement time was less than 1s. The temperature measurement system had the advantages of handy use, good flexibility, high reliability, and had a promotional value.

  12. Cooled and uncooled infrared detectors for missile seekers

    Science.gov (United States)

    Fraenkel, Rami; Haski, Jacob; Mizrahi, Udi; Shkedy, Lior; Shtrichman, Itay; Pinsky, Ephi

    2014-06-01

    Electro-optical missile seekers pose exceptional requirements for infrared (IR) detectors. These requirements include: very short mission readiness (time-to-image), one-time and relatively short mission duration, extreme ambient conditions, high sensitivity, fast frame rate, and in some cases small size and cost. SCD is engaged in the development and production of IR detectors for missile seeker applications for many years. 0D, 1D and 2D InSb focal plane arrays (FPAs) are packaged in specially designed fast cool-down Dewars and integrated with Joule-Thomson (JT) coolers. These cooled MWIR detectors were integrated in numerous seekers of various missile types, for short and long range applications, and are combat proven. New technologies for the MWIR, such as epi-InSb and XBn-InAsSb, enable faster cool-down time and higher sensitivity for the next generation seekers. The uncooled micro-bolometer technology for IR detectors has advanced significantly over the last decade, and high resolution - high sensitivity FPAs are now available for different applications. Their much smaller size and cost with regard to the cooled detectors makes these uncooled LWIR detectors natural candidates for short and mid-range missile seekers. In this work we will present SCD's cooled and uncooled solutions for advanced electro-optical missile seekers.

  13. Portable He-3 detector cryostat for the far infrared

    Science.gov (United States)

    Radostitz, J. V.; Nolt, I. G.; Kittel, P.; Donnelly, R. J.

    1978-01-01

    The design of a portable He-3 cryostat for far infrared detection applications is described, with a cutaway drawing of the cryostat, including bolometer and cooled optics, provided. Consideration is given to the selection and testing of various bolometer materials, including Ge:Ga and Ge:InSb; the resistance-temperature coefficients of the materials examined are presented. The absolute flux calibration of the detector system using a new temperature-modulated cold source method is described.

  14. Optical Studies on Antimonide Superlattice Infrared Detector Material

    Science.gov (United States)

    Hoglund, Linda; Soibel, Alexander; Hill, Cory J.; Ting, David Z.; Khoshakhlagh, Arezou; Liao, Anna; Keo, Sam; Lee, Michael C.; Nguyen, Jean; Mumolo, Jason M.; hide

    2010-01-01

    In this study the material quality and optical properties of type II InAs/GaSb superlattices are investigated using transmission and photoluminescence (PL) spectroscopy. The influence of the material quality on the intensity of the luminescence and on the electrical properties of the detectors is studied and a good correlation between the photodetector current-voltage (IV) characteristics and the PL intensity is observed. Studies of the temperature dependence of the PL reveal that Shockley-Read-Hall processes are limiting the minority carrier lifetime in both the mid-IR wavelength and the long-IR wavelength detector material studied. These results demonstrate that PL spectroscopy is a valuable tool for optimization of infrared detectors.

  15. Kinetic inductance detectors for far-infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Barlis, A., E-mail: abarlis@physics.upenn.edu [University of Pennsylvania Department of Physics and Astronomy, Philadelphia, Pennsylvania (United States); Aguirre, J. [University of Pennsylvania Department of Physics and Astronomy, Philadelphia, Pennsylvania (United States); Stevenson, T. [NASA Goddard Space Flight Center, Greenbelt, Maryland (United States)

    2016-07-11

    The star formation mechanisms at work in the early universe remain one of the major unsolved problems of modern astrophysics. Many of the luminous galaxies present during the period of peak star formation (at redshift of about 2.5) were heavily enshrouded in dust, which makes observing their properties difficult at optical wavelengths. However, many spectral lines exist at far-infrared wavelengths that serve as tracers of star formation. Here, we describe a detector system suitable for a balloon-borne spectroscopic intensity mapping experiment at far-infrared wavelengths. The system uses lumped-element kinetic inductance detectors (KIDs), which have the potential to achieve high sensitivity and low noise levels. KIDs consist of separate capacitive and inductive elements, and use the inductive element as the radiation absorber. We describe the design considerations, fabrication process, and readout scheme for a prototype LEKID array of 1600 pixels. - Highlights: • We describe a concept for a balloon-borne telescope for far-IR wavelengths. • Telescope would use high-sensitivity kinetic inductance detectors. • Design considerations and fabrication process for prototype detectors.

  16. Pyroelectric Quantum Well Energy Harvesters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the investigation of pyroelectric energy harvesters with enhanced efficiencies through quantum wells induced by a multilayer design.  Pyroelectric...

  17. Pyroelectric sensor arrays for detection and thermal imaging

    Science.gov (United States)

    Holden, Anthony J.

    2013-06-01

    Penetration of uncooled (room temperature operation) thermal detector arrays into high volume commercial products depends on very low cost technology linked to high volume production. A series of innovative and revolutionary developments is now allowing arrays based on bulk pyroelectric ceramic material to enter the consumer marketplace providing everything from sophisticated security and people monitoring devices to hand held thermal imagers and visual IR thermometers for preventative maintenance and building inspection. Although uncooled resistive microbolometer detector technology has captured market share in higher cost thermal imager products we describe a pyroelectric ceramic technology which does not need micro electro-mechanical systems (MEMS) technology and vacuum packaging to give good performance. This is a breakthrough for very low cost sensors and imagers. Recent developments in a variety of products based on pyroelectric ceramic arrays are described and their performance and applicability compared and contrasted with competing technologies.

  18. Cooling and shielding systems for infrared detectors - requirements and limits.

    Science.gov (United States)

    Wiecek, B

    2005-01-01

    This paper presents three main cooling systems used for infrared detectors. At first thermoelectric devices are discussed. They allow cooling down the detector with low efficiency and not to the very low temperature. They do not generate any vibrations and therefore are suitable for thermal detectors, where the microphone effect can decrease their performance. Photon detectors need to be cooled down even to 77K or better. The only way to have such deep cooling is to use the cooler based on thermodynamic cycle such as Stirling one. With the high efficiency one can easily obtain cryogenic temperature for a detector. The electromagnetic noise and vibration generation are the main disadvantages of using such devices. Joule-Thomson effect during gas expansion is 3rdcooling system discussed in the paper. It is highly effective process, used for gas liquefaction too. The working gas is being removed during cooling into the atmosphere, so the need of continuous supplying with compressed one, what makes this system very difficult for remote applications. In the paper, simple calculations are presented to illustrate the advantages and disadvantages of the different cooling systems.

  19. Dynamics of pyroelectric accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ghaderi, R.; Davani, F. Abbasi, E-mail: fabbasi@sbu.ac.ir [Radiation Application Department, Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2015-01-26

    Pyroelectric crystals are used to produce high energy electron beams. We have derived a method to model electric potential generation on LiTaO{sub 3} crystal during heating cycle. In this method, effect of heat transfer on the potential generation is investigated by some experiments. In addition, electron emission from the crystal surface is modeled by measurements and analysis. These spectral data are used to present a dynamic equation of electric potential with respect to thickness of the crystal and variation of its temperature. The dynamic equation's results for different thicknesses are compared with measured data. As a result, to attain more energetic electrons, best thickness of the crystals could be extracted from the equation. This allows for better understanding of pyroelectric crystals and help to study about current and energy of accelerated electrons.

  20. Surface Leakage Mechanisms in III-V Infrared Barrier Detectors

    Science.gov (United States)

    Sidor, D. E.; Savich, G. R.; Wicks, G. W.

    2016-09-01

    Infrared detector epitaxial structures employing unipolar barriers exhibit greatly reduced dark currents compared to simple pn-based structures. When correctly positioned within the structure, unipolar barriers are highly effective at blocking bulk dark current mechanisms. Unipolar barriers are also effective at suppressing surface leakage current in infrared detector structures employing absorbing layers that possess the same conductivity type in their bulk and at their surface. When an absorbing layer possesses opposite conductivity types in its bulk and at its surface, unipolar barriers are not solutions to surface leakage. This work reviews empirically determined surface band alignments of III-V semiconductor compounds and modeled surface band alignments of both gallium-free and gallium-containing type-II strained layer superlattice material systems. Surface band alignments are used to predict surface conductivity types in several detector structures, and the relationship between surface and bulk conductivity types in the absorbing layers of these structures is used as the basis for explaining observed surface leakage characteristics.

  1. Megapixel digital InSb detector for midwave infrared imaging

    Science.gov (United States)

    Shkedy, Lior; Markovitz, Tuvy; Calahorra, Zipi; Hirsh, Itay; Shtrichman, Itay

    2011-06-01

    Since the late 1990s Semiconductor devices (SCDs) has developed and manufactured a variety of InSb two-dimensional (2D) focal plane arrays (FPAs) that were implemented in many infrared (IR) systems and applications. SCD routinely manufactures both analog and digital InSb FPAs with array formats of 320×256, 480×384, and 640×512 elements, and pitch size in the range 15 to 30 μm. These FPAs are available in many packaging configurations, including fully integrated detector-Dewar-cooler-assembly, with either closed-cycle Stirling or open-loop Joule-Thomson coolers. In response to a need for very high resolution midwave IR (MWIR) detectors and systems, SCD has developed a large format 2D InSb detector with 1280×1024 elements and pixel size of 15 μm. A digital readout integrated circuit (ROIC) is coupled by flip-chip bonding to the megapixel InSb array. The ROIC is fabricated in CMOS 0.18-μm technology, that enables the small pixel circuitry and relatively low power generation at the focal plane. The digital ROIC has an analog to digital (A/D) converter per-channel and allows for full frame readout at a rate of 100 Hz. Such on-chip A/D conversion eliminates the need for several A/D converters with fairly high power consumption at the system level. The digital readout, together with the InSb detector technology, lead to a wide linear dynamic range and low residual nonuniformity, which is stable over a long period of time following a nonuniformity correction procedure. A special Dewar was designed to withstand harsh environmental conditions while minimizing the contribution to the heat load of the detector. The Dewar together with the low power ROIC, enable a megapixel detector with overall low size, weight, and power with respect to comparable large format detectors. A variety of applications with this detector make use of different cold shields with different f-number and spectral filters. In this paper we present actual performance characteristics of the

  2. An integrated charge amplifier for a pyroelectric sensor

    NARCIS (Netherlands)

    Setiadi, D.; Armitage, A.; Binnie, T.D.; Regtien, P.P.L.; Sarro, P.M.

    1997-01-01

    This paper presents an integrated charge amplifier that measures a small charge. This charge is generated by a pyroelectric detector. The charge amplifier consists of a single-stage c-annon source configuration with a passive feedback network. The charge amplifier has a bandwidth of 700 kHz and an o

  3. Crosstalk study of near infrared InGaAs detectors

    Science.gov (United States)

    Li, Xue; Tang, Hengjing; Li, Tao; Fan, Cui; Shao, Xiumei; Li, Jianwei; Wei, Jun; Gong, Haimei

    2016-05-01

    Crosstalk characteristics of high density FPA detectors attract widespread attention in the application of electro-optical systems. Crosstalk characteristics of near-infrared (NIR) InGaAs photodiodes and focal plane arrays (FPAs) were studied in this paper. The mesa type detector was investigated by using laser beam induced current technique (LBIC) to measure the absorption outside the designed photosensitive area, and the results show that the excess absorption enlarges the crosstalk of the adjacent pixels. The structure optimization using the effective absorption layer between the pixels can effectively reduce the crosstalk to 2.5%. The major crosstalk components of the optimization photodiode come from the electronic signal caused by carrier lateral diffusion. For the planar type detectors, test structures were used to compare the crosstalk of different structures, and the guard ring structure shows good suppression of the crosstalk. Then the back-illuminated 32x32 InGaAs photodiodes with 30μm pitch were designed, and LBIC was used to measure its lateral diffusion of the effective carriers and fill factor of photosensitive area. The results indicate that the fill factor of detectors can reach up to 98% when the diffusion region is optimized, and the minimum response exists between two neighborhood pixels. Based on these crosstalk measurement results and optimizing structure designs, the linear InGaAs photodiodes were designed and thus the InGaAs FPA assembly was fabricated. The assembly shows higher electro-optical performance and good improvement on crosstalk. The assembly was applied in infrared imaging system and modulation transfer function (MTF) of FPA assembly was calculated to be above 0.50. The clear image based on FPA assembly was obtained.

  4. Kinetic inductance detectors for far-infrared spectroscopy

    Science.gov (United States)

    Barlis, Alyssa; Aguirre, James; Stevenson, Thomas

    2016-07-01

    The star formation mechanisms at work in the early universe remain one of the major unsolved problems of modern astrophysics. Many of the luminous galaxies present during the period of peak star formation (between redshifts 1 and 3) were heavily enshrouded in dust, which makes observing their properties difficult at optical wavelengths. However, many spectral lines exist at far-infrared wavelengths that serve as tracers of star formation during that period, in particular fine structure lines of nitrogen, carbon, and oxygen, as well as the carbon monoxide molecule. Using an observation technique known as intensity mapping, it would be possible to observe the total line intensity for a given redshift range even without detecting individual sources. Here, we describe a detector system suitable for a balloonborne spectroscopic intensity mapping experiment at far-infrared wavelengths. The experiment requires an "integralfield" type spectrograph, with modest spectral resolution (R 100) for each of a number of spatial pixels spanning several octaves in wavelength. The detector system uses lumped-element kinetic inductance detectors (LEKIDs), which have the potential to achieve the high sensitivity, low noise, and high multiplexing factor required for this experiment. We detail the design requirements and considerations, and the fabrication process for a prototype LEKID array of 1600 pixels. The pixel design is driven by the need for high responsivity, which requires a small physical volume for the LEKID inductor. In order to minimize two-level system noise, the resonators include large-area interdigitated capacitors. High quality factor resonances are required for a large frequency multiplexing factor. Detectors were fabricated using both trilayer TiN/Ti/TiN recipes and thin-film Al, and are operated at base temperatures near 250 mK.

  5. ESTIMATION OF INTRUSION DETECTION PROBABILITY BY PASSIVE INFRARED DETECTORS

    Directory of Open Access Journals (Sweden)

    V. V. Volkhonskiy

    2015-07-01

    Full Text Available Subject of Research. The paper deals with estimation of detection probability of intruder by passive infrared detector in different conditions of velocity and direction for automated analyses of physical protection systems effectiveness. Method. Analytic formulas for detection distance distribution laws obtained by means of experimental histogram approximation are used. Main Results. Applicability of different distribution laws has been studied, such as Rayleigh, Gauss, Gamma, Maxwell and Weibull distribution. Based on walk tests results, approximation of experimental histograms of detection distance probability distribution laws by passive infrared detectors was done. Conformity of the histograms to the mentioned analytical laws according to fitting criterion 2 has been checked for different conditions of velocity and direction of intruder movement. Mean and variance of approximate distribution laws were equal to the same parameters of experimental histograms for corresponding intruder movement parameters. Approximation accuracy evaluation for above mentioned laws was done with significance level of 0.05. According to fitting criterion 2, the Rayleigh and Gamma laws are corresponded mostly close to the histograms for different velocity and direction of intruder movement. Dependences of approximation accuracy for different conditions of intrusion have been got. They are usable for choosing an approximation law in the certain condition. Practical Relevance. Analytic formulas for detection probability are usable for modeling of intrusion process and objective effectiveness estimation of physical protection systems by both developers and users.

  6. Compact dewar and electronics for large-format infrared detectors

    Science.gov (United States)

    Manissadjian, A.; Magli, S.; Mallet, E.; Cassaigne, P.

    2011-06-01

    Infrared systems cameras trend is to require higher performance (thanks to higher resolution) and in parallel higher compactness for easier integration in systems. The latest developments at SOFRADIR / France on HgCdTe (Mercury Cadmium Telluride / MCT) cooled IR staring detectors do show constant improvements regarding detector performances and compactness, by reducing the pixel pitch and optimizing their encapsulation. Among the latest introduced detectors, the 15μm pixel pitch JUPITER HD-TV format (1280×1024) has to deal with challenging specifications regarding dewar compactness, low power consumption and reliability. Initially introduced four years ago in a large dewar with a more than 2kg split Stirling cooler compressor, it is now available in a new versatile compact dewar that is vacuum-maintenance-free over typical 18 years mission profiles, and that can be integrated with the different available Stirling coolers: K548 microcooler for light solution (less than 0.7 kg), K549 or LSF9548 for split cooler and/or higher reliability solution. The IDDCAs are also required with simplified electrical interface enabling to shorten the system development time and to standardize the electronic boards definition with smaller volumes. Sofradir is therefore introducing MEGALINK, the new compact Command & Control Electronics compatible with most of the Sofradir IDDCAs. MEGALINK provides all necessary input biases and clocks to the FPAs, and digitizes and multiplexes the video outputs to provide a 14 bit output signal through a cameralink interface, in a surface smaller than a business card.

  7. Curved infrared detectors: application to spectrometry and astronomy

    Science.gov (United States)

    Dumas, D.; Fendler, M.; Berger, F.; Marion, F.; Arnaud, A.; Vialle, C.; Goudon, V.; Primot, J.; Le Coarer, E.; Ribot, H.

    2010-07-01

    The traditional design of optical systems is severely complicated by the curved shape of the image surface which has to be recorded on a planar retina. This constraint decreases the image quality; optical elements are then added to avoid aberrations and lead to increase the dimensions of the system. However, miniaturization could be achieved, without decreasing resolution and sensibility, by recording the image surface on a curved retina. The optical advantages of curved sensors have been demonstrated; the simplification leads to scale down the entire system. Moreover, the hemispherical shape increases the field of view (FOV). In this paper the advantages of curved focal plane will be detailed through two applications: spectrometry and large FOV telescopes. In astronomy, large FOV and miniaturization with good resolution can only be achieved by curving the focal plane; the difficulty is to curve in a hemispherical shape large detectors. The advantages are highlighted by the European Extremely Large Telescope (E-ELT) project. Despite this high interest in curved detectors, only few articles are dedicated to this hemispherical shape technology. Some solutions exist, which mainly consist in structuring the die in sub-devices. We propose a solution to curve an IR sensor with a fill factor equal to 100%. To do so, we developed a dedicated bonding process which allows curving silicon using its mechanical properties. A curved uncooled infrared detector has been performed without mechanical and electrical damage.

  8. Chemical imaging of cotton fibers using an infrared microscope and a focal-plane array detector

    Science.gov (United States)

    In this presentation, the chemical imaging of cotton fibers with an infrared microscope and a Focal-Plane Array (FPA) detector will be discussed. Infrared spectroscopy can provide us with information on the structure and quality of cotton fibers. In addition, FPA detectors allow for simultaneous spe...

  9. Can graphene make better HgCdTe infrared detectors?

    Directory of Open Access Journals (Sweden)

    Shi Yanli

    2011-01-01

    Full Text Available Abstract We develop a simple and low-cost technique based on chemical vapor deposition from which large-size graphene films with 5-10 graphene layers can be produced reliably and the graphene films can be transferred easily onto HgCdTe (MCT thin wafers at room temperature. The proposed technique does not cause any thermal and mechanical damages to the MCT wafers. It is found that the averaged light transmittance of the graphene film on MCT thin wafer is about 80% in the mid-infrared bandwidth at room temperature and 77 K. Moreover, we find that the electrical conductance of the graphene film on the MCT substrate is about 25 times larger than that of the MCT substrate at room temperature and 77 K. These experimental findings suggest that, from a physics point of view, graphene can be utilized as transparent electrodes as a replacement for metal electrodes while producing better and cheaper MCT infrared detectors.

  10. Radiation generation with pyroelectric crystals

    Science.gov (United States)

    Geuther, Jeffrey A.

    2007-12-01

    Pyroelectric crystals heated or cooled in vacuum have been used to produce low-energy x-ray devices since 1992. In the course of this thesis, experiments with lithium tantalate (LiTaO3) and lithium niobate (LiNbO 3) were performed to extend the usefulness of pyroelectric radiation sources. Paired-crystal x-ray generators were shown to double the x-ray energy and yield, and allow the k-shell fluorescence of any metal up to thorium (Z = 90). It was demonstrated that the electron emission from a single pyroelectric crystal could be transmitted through a beryllium window to allow the electron beam to be extracted from the vacuum chamber. The electron emission current and energy were measured, and a mathematical model was developed to predict emission current and energy. Magnetic deflection experiments were used to verify that the electric field produced by the pyroelectric effect in lithium tantalate was sufficient to ionize gas. Finally, a paired-crystal system was used to ionize a deuterium fill gas near a metallic tip mounted to a pyroelectric crystal, and accelerate these ions into a deuterated target mounted to the opposing crystal. This technique was used to produce a compact, low-power fusion neutron source driven by pyroelectric crystals.

  11. Two-color detector: Mercury-cadmium-telluride as a terahertz and infrared detector

    Energy Technology Data Exchange (ETDEWEB)

    Sizov, F.; Zabudsky, V.; Petryakov, V.; Golenkov, A.; Andreyeva, K.; Tsybrii, Z. [Institute of Semiconductor Physics, 03028 Kiev (Ukraine); Dvoretskii, S. [Institute of Semiconductor Physics of SB RAS, 630090 Novosibirsk (Russian Federation)

    2015-02-23

    In this paper, issues associated with the development of infrared (IR) and terahertz (THz) radiation detectors based on HgCdTe are discussed. Two-color un-cooled and cooled to 78 K narrow-gap mercury-cadmium-telluride semiconductor thin layers with antennas were considered both as sub-THz (sub-THz) direct detection bolometers and 3–10 μm IR photoconductors. The noise equivalent power (NEP) for one of the detectors studied at ν ≈ 140 GHz reaches NEP{sub 300 K} ≈ 4.5 × 10{sup −10} W/Hz{sup 1/2} and NEP{sub 78 K} ≈ 5 × 10{sup −9} W/Hz{sup 1/2}. The same detector used as an IR photoconductor showed the responsivity at temperatures T = 78 K and 300 K with signal-to-noise ratio S/N ≈ 750 and 50, respectively, under illumination by using IR monochromator and globar as a thermal source.

  12. Pyroelectric response of spray-deposited BaTiO3 thin film

    Science.gov (United States)

    Peale, Robert E.; Oladeji, Isaiah O.; Smith, Evan M.; Vasilyev, Vladimir; Alhasan, Sarmad Fawzi Hamza; Abouelkhair, Hussain; Todorovski, Dalibor; Kimani, Martin; Cleary, Justin W.

    2016-09-01

    Pyroelectric photoresponse of aqueous spray deposited thin films containing BaTiO3 nano-crystals is reported. X-ray diffraction data indicate the presence of hexagonal BaTiO3 nano-crystals with 20 nm crystalline domains in a matrix of some as yet unidentified nano-crystalline material. When the film is annealed at 600 C, the X-ray pattern changes significantly and indicates a conversion to one of the non-hexagonal phases of BaTiO3 as well as a complete change in the matrix. With suitable amplifier, the measured photoresponse was 40V/W. Ferroelectric hysteresis on a film with significant presence of hexagonal BaTiO3 shows saturated polarization which is about 5-times smaller than for the bulk tetragonal phase. A potential application is a patternable infrared detector for photonic and plasmonic devices, such as chip-scale spectral sensors.

  13. Unattended safety control system based on pyroelectric infrared sensor%基于热释红外传感器无人值守的安全控制系统

    Institute of Scientific and Technical Information of China (English)

    王良升; 郭杰荣; 黄民; 肖利平; 王瑞成

    2015-01-01

    This system scanning the workplace environment uses the pyroelectric infrared module to determine whether there are persons in the presence. And then send information to the CPU through the plurality of wireless modules nRF24L01, and the central processor executes corresponding control through the corresponding electric appliances or control switch. The system adopts the wireless receiving and sending, the infrared sensor technology, wireless communication technology, combined with single-chip microcomputer technology and computer application technology, work closely with each other to achieve the unattended environment management, which has good market application value.%采用热释电人体红外感应模块对工作场所环境扫描检测以判断有无人员在场,然后通过多个无线模块nRF24L01发送信息给中央处理器,中央处理器再对相应的用电器或者开关等进行相应的控制。系统采用无线接收与发送来实现匹配,并且将红外传感技术、无线通信技术、单片机技术与计算机应用技术结合实现对无人值守环境的管理,具有较好的市场应用价值。

  14. Fluid flow and heat transfer in Joule-Thomson coolers coupled with infrared detectors

    Science.gov (United States)

    Du, Bingyan; Jia, Weimin

    2011-08-01

    Joule-Thomson coolers have been widely used in infrared detectors with respect to compact, light and low cost. For self-regulating Joule-Thomson cooler, its performance is required to be improved with the development of higher mass and larger diameter of focal plane infrared detectors. Self-regulating Joule-Thomson coolers use a limited supply of high pressure gas to support the cooling of infrared detectors. In order to develop Joule-Thomson coolers with a given volume of stored gas, it is important to study on fluid flow and heat transfer of Joule-Thomson coolers coupled with infrared detectors, especially the starting time of Joule-Thomson coolers. A serial of experiments of Joule-Thomson coolers coupled with 128×128 focal plane infrared detectors have been carried out. The exchanger of coolers are made of a d=0.5mm capillary finned with a copper wire. The coolers are self-regulated by bellows and the diameters are about 8mm. Nitrogen is used as working gas. The effect of pressure of working gas has been studied. The relation between starting time and pressure of working gas is proved to fit exponential decay. Error analysis has also been carried. It is crucial to study the performance of Joule-Thomson coolers coupled with infrared detectors. Deeper research on Joule-Thomson coolers will be carried on to improve the Joule-Thomson coolers for infrared detectors.

  15. Experiments to Demonstrate Piezoelectric and Pyroelectric Effects

    Science.gov (United States)

    Erhart, Jirí

    2013-01-01

    Piezoelectric and pyroelectric materials are used in many current applications. The purpose of this paper is to explain the basic properties of pyroelectric and piezoelectric effects and demonstrate them in simple experiments. Pyroelectricity is presented on lead zirconium titanate (PZT) ceramics as an electric charge generated by the temperature…

  16. Infrared Sensor with Liquid Crystal Chopper

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An infrared sensor using the liquid crystal chopper is presented. The infrared sensor is designed to detect infrared rays with a pyroelectric element used as a liquid crystal chopper in such an infrared sensor or the like.

  17. High operating temperature InAlSb infrared detectors

    Science.gov (United States)

    Li, Mo; Chen, Gang; Li, Hao; Zhang, Zhaofan; Peng, Pan; Lv, Yanqiu

    2016-10-01

    The recent progresses of our research in InxAl1-xSb infrared detector based on molecular beam epitaxy are presented. Al composition with 0-0.3 is used for adjusting energy gaps of InSb and a p-i-n structure is utilized to decrease dark current. InxAl1-xSb ternary alloys are grown by molecular beam epitaxy on InSb substrates, and the material quality is characterized using high resolution x-ray diffraction. In order to exploit this epitaxial material we have developed new mesa and passivation technology based on matured InSb fabrication process. The InAlSb diodes has a cut-off wavelength of around 4.8μm. The reverse bias dark current of InAlSb diodes have been measured. The dark current of the pin InAlSb diode is seen to smaller that of the bulk p+n InSb diodes by 4-5 times in 77K.

  18. Application of LiTaO{sub 3} pyroelectric crystal for pulsed neutron detection

    Energy Technology Data Exchange (ETDEWEB)

    Liang, W.F., E-mail: liang_wen_feng@163.com [CAEP Key Laboratory of Neutron Physics, Mianyang 621900 (China); Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China); Lu, Y.; Wu, J.; Gao, H.; Li, M. [CAEP Key Laboratory of Neutron Physics, Mianyang 621900 (China); Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China)

    2016-08-11

    The feasibility of a LiTaO{sub 3} pyroelectric crystal for pulsed neutron detection has been studied. The detector consists of a slice of electroded Z-cut LiTaO{sub 3} pyroelectric crystal, and no additional neutron converter is required owing to the Li contained in the crystal. The slight temperature increase caused by neutron radiation will lead to the release of bound charges and will give rise to a pyroelectric signal. The response of it has been studied both theoretically and experimentally. Our preliminary experiment on the CFBR-II reactor suggests that the LiTaO{sub 3} pyroelectric detector is promising for high intensity neutron – pulse measurement. - Highlights: • LiTaO{sub 3} pyroelectric neutron detector can be used with no additional neutron converter. • Relationship between the pulsed neutron field and the voltage signal was obtained. • Experiment was carried out to test the response of LiTaO{sub 3} detector. • Feasibility of LiTaO{sub 3} for intense neutron pulse measurement was confirmed.

  19. Turn-key Near-Infrared Photon-Counting Detector Module for LIDAR Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design and deliver a turn-key photon counting detector module for near-infrared wavelengths, based on large-area InGaAs/InP avalanche photodiodes...

  20. Doping-Spike PtSi Schottky Infrared Detectors with Extended Cutoff Wavelengths

    Science.gov (United States)

    Lin, T. L.; Park, J. S.; Gunapala, S. D.; Jones, E. W.; Castillo, H. M. Del

    1994-01-01

    A technique incorporating a p+ doping spike at the silicide/Si interface to reduce the effective Schottky barrier of the silicide infrared detectors and thus extend the cutoff wavelength has been developed.

  1. Fast Readout for Large Area Photon-Counting Infrared Detectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Many NASA space and Earth programs in the infrared range 1060-1550 nm are limited by the detector performance that require long exposure time due to their low...

  2. MEMS based pyroelectric thermal energy harvester

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, Scott R; Datskos, Panagiotis G

    2013-08-27

    A pyroelectric thermal energy harvesting apparatus for generating an electric current includes a cantilevered layered pyroelectric capacitor extending between a first surface and a second surface, where the first surface includes a temperature difference from the second surface. The layered pyroelectric capacitor includes a conductive, bimetal top electrode layer, an intermediate pyroelectric dielectric layer and a conductive bottom electrode layer. In addition, a pair of proof masses is affixed at a distal end of the layered pyroelectric capacitor to face the first surface and the second surface, wherein the proof masses oscillate between the first surface and the second surface such that a pyroelectric current is generated in the pyroelectric capacitor due to temperature cycling when the proof masses alternately contact the first surface and the second surface.

  3. High Operating Temperature Midwave Quantum Dot Barrier Infrared Detector (QD-BIRD)

    Science.gov (United States)

    Ting, David Z.; Soibel, Alexander; Hill, Cory J.; Keo, Sam A.; Mumolo, Jason M.; Gunapala, Sarath D.

    2012-01-01

    The nBn or XBn barrier infrared detector has the advantage of reduced dark current resulting from suppressed Shockley-Read-Hall (SRH) recombination and surface leakage. High performance detectors and focal plane arrays (FPAs) based on InAsSb absorber lattice matched to GaSb substrate, with a matching AlAsSb unipolar electron barrier, have been demonstrated. The band gap of lattice-matched InAsSb yields a detector cutoff wavelength of approximately 4.2 ??m when operating at 150K. We report results on extending the cutoff wavelength of midwave barrier infrared detectors by incorporating self-assembled InSb quantum dots into the active area of the detector. Using this approach, we were able to extend the detector cutoff wavelength to 6 ?m, allowing the coverage of the full midwave infrared (MWIR) transmission window. The quantum dot barrier infrared detector (QD-BIRD) shows infrared response at temperatures up to 225 K.

  4. High Operating Temperature Midwave Quantum Dot Barrier Infrared Detector (QD-BIRD)

    Science.gov (United States)

    Ting, David Z.; Soibel, Alexander; Hill, Cory J.; Keo, Sam A.; Mumolo, Jason M.; Gunapala, Sarath D.

    2012-01-01

    The nBn or XBn barrier infrared detector has the advantage of reduced dark current resulting from suppressed Shockley-Read-Hall (SRH) recombination and surface leakage. High performance detectors and focal plane arrays (FPAs) based on InAsSb absorber lattice matched to GaSb substrate, with a matching AlAsSb unipolar electron barrier, have been demonstrated. The band gap of lattice-matched InAsSb yields a detector cutoff wavelength of approximately 4.2 ??m when operating at 150K. We report results on extending the cutoff wavelength of midwave barrier infrared detectors by incorporating self-assembled InSb quantum dots into the active area of the detector. Using this approach, we were able to extend the detector cutoff wavelength to 6 ?m, allowing the coverage of the full midwave infrared (MWIR) transmission window. The quantum dot barrier infrared detector (QD-BIRD) shows infrared response at temperatures up to 225 K.

  5. Far infrared thermal detectors for laser radiometry using a carbon nanotube array

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, John H.; Lee, Bob; Grossman, Erich N.

    2011-07-20

    We present a description of a 1.5 mm long, vertically aligned carbon nanotube array (VANTA) on a thermopile and separately on a pyroelectric detector. Three VANTA samples, having average lengths of 40 {mu}m, 150 {mu}m, and 1.5 mm were evaluated with respect to reflectance at a laser wavelength of 394 {mu}m(760 GHz), and we found that the reflectance decreases substantially with increasing tube length, ranging from 0.38 to 0.23 to 0.01, respectively. The responsivity of the thermopile by electrical heating (98.4 mA/W) was equal to that by optical heating (98.0 mA/W) within the uncertainty of the measurement. We analyzed the frequency response and temporal response and found a thermal decay period of 500 ms, which is consistent with the specific heat of comparable VANTAs in the literature. The extremely low (0.01) reflectance of the 1.5 mm VANTAs and the fact that the array is readily transferable to the detector's surface is, to our knowledge, unprecedented.

  6. Equipment for Topographical Preparation and Analysis of Various Semiconductor Infrared Detector Samples

    Science.gov (United States)

    2015-11-13

    Approved for Public Release; Distribution Unlimited Final Report: Equipment for Topographical Preparation and Analysis of Various Semiconductor Infrared...Final Report: Equipment for Topographical Preparation and Analysis of Various Semiconductor Infrared Detector Samples Report Title A used calibrated...camera will reinitialize and the video settings have to be reset. 6 Figure 4. This will open the both video overlay and the Dektak

  7. Type-II indium arsenide/gallium antimonide superlattices for infrared detectors

    Science.gov (United States)

    Mohseni, Hooman

    In this work, the unique properties of type-II InAs/GaSb heterojunctions were utilized for the realization of novel infrared photodetectors with higher operating temperature, detectivity and uniformity than the commonly available infrared detectors. This effort was concentrated on two major devices: uncooled infrared detectors in the long wavelength infrared (LWIR) range, and cooled devices in the very long wavelength infrared (VLWIR) range. Uncooled infrared (IR) detectors are required for low-cost, lightweight sensor systems that have many industrial and medical applications. Commercially available uncooled IR sensors use ferroelectric or microbolometer detectors. These sensors are inherently slow and cannot detect rapid signal changes needed for high-speed infrared systems. Some of the applications which require a fast detector (tau LIDARs. Although photon detectors have frequency responses in the megahertz range, their high temperature detectivity is severely degraded due to high Auger recombination rates. Bandgap engineering was used in order to suppress Auger recombination at room temperature in type-II superlattices. Our experimental results demonstrated nearly one order of magnitude lower Auger recombination rate at room temperature in these type-II superlattices compared to typical intrinsic detectors, such as HgCdTe, with similar bandgap. Uncooled detectors based on the engineered superlattices showed a detectivity of 1.3 x 108g cmHz 1/2/W at 11 Et m, which is comparable to microbolometers. However, the measured response time of the detectors was more than five orders of magnitude faster than microbolometers. In parallel, devices for operation in the VLWIR were developed. High-performance infrared detectors with cutoff wavelength above 14 mum are highly needed for many space-based applications. Commonly used detectors are extrinsic silicon and HgCdTe. However, the former has to be cooled below 10K, and the latter do not have good uniformity in the VLWIR

  8. A Strip Cell in Pyroelectric Devices

    Directory of Open Access Journals (Sweden)

    An-Shen Siao

    2016-03-01

    Full Text Available The pyroelectric effect affords the opportunity to convert temporal temperature fluctuations into usable electrical energy in order to develop abundantly available waste heat. A strip pyroelectric cell, used to enhance temperature variation rates by lateral temperature gradients and to reduce cell capacitance to further promote the induced voltage, is described as a means of improving pyroelectric energy transformation. A precision dicing saw was successfully applied in fabricating the pyroelectric cell with a strip form. The strip pyroelectric cell with a high-narrow cross section is able to greatly absorb thermal energy via the side walls of the strips, thereby inducing lateral temperature gradients and increasing temperature variation rates in a thicker pyroelectric cell. Both simulation and experimentation show that the strip pyroelectric cell improves the electrical outputs of pyroelectric cells and enhances the efficiency of pyroelectric harvesters. The strip-type pyroelectric cell has a larger temperature variation when compared to the trenched electrode and the original type, by about 1.9 and 2.4 times, respectively. The measured electrical output of the strip type demonstrates a conspicuous increase in stored energy as compared to the trenched electrode and the original type, by of about 15.6 and 19.8 times, respectively.

  9. Ferroelectric ceramics in a pyroelectric accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Shchagin, A. V., E-mail: shchagin@kipt.kharkov.ua [Kharkov Institute of Physics and Technology, Kharkov 61108 (Ukraine); Belgorod State University, Belgorod 308015 (Russian Federation); Miroshnik, V. S.; Volkov, V. I. [Kharkov Institute of Physics and Technology, Kharkov 61108 (Ukraine); Oleinik, A. N. [Belgorod State University, Belgorod 308015 (Russian Federation)

    2015-12-07

    The applicability of polarized ferroelectric ceramics as a pyroelectric in a pyroelectric accelerator is shown by experiments. The spectra of X-ray radiation of energy up to tens of keV, generated by accelerated electrons, have been measured on heating and cooling of the ceramics in vacuum. It is suggested that curved layers of polarized ferroelectric ceramics be used as elements of ceramic pyroelectric accelerators. Besides, nanotubes and nanowires manufactured from ferroelectric ceramics are proposed for the use in nanometer-scale ceramic pyroelectric nanoaccelerators for future applications in nanotechnologies.

  10. Study on Pyroelectric Harvesters with Various Geometry

    Directory of Open Access Journals (Sweden)

    An-Shen Siao

    2015-08-01

    Full Text Available Pyroelectric harvesters convert time-dependent temperature variations into electric current. The appropriate geometry of the pyroelectric cells, coupled with the optimal period of temperature fluctuations, is key to driving the optimal load resistance, which enhances the performance of pyroelectric harvesters. The induced charge increases when the thickness of the pyroelectric cells decreases. Moreover, the induced charge is extremely reduced for the thinner pyroelectric cell when not used for the optimal period. The maximum harvested power is achieved when a 100 μm-thick PZT (Lead zirconate titanate cell is used to drive the optimal load resistance of about 40 MΩ. Moreover, the harvested power is greatly reduced when the working resistance diverges even slightly from the optimal load resistance. The stored voltage generated from the 75 μm-thick PZT cell is less than that from the 400 μm-thick PZT cell for a period longer than 64 s. Although the thinner PZT cell is advantageous in that it enhances the efficiency of the pyroelectric harvester, the much thinner 75 μm-thick PZT cell and the divergence from the optimal period further diminish the performance of the pyroelectric cell. Therefore, the designers of pyroelectric harvesters need to consider the coupling effect between the geometry of the pyroelectric cells and the optimal period of temperature fluctuations to drive the optimal load resistance.

  11. Heated Surface Temperatures Measured by Infrared Detector in a Cascade Environment

    Science.gov (United States)

    Boyle, Robert J.

    2002-01-01

    Investigators have used infrared devices to accurately measure heated surface temperatures. Several of these applications have been for turbine heat transfer studies involving film cooling and surface roughness, typically, these measurements use an infrared camera positioned externally to the test section. In cascade studies, where several blades are used to ensure periodic flow, adjacent blades block the externally positioned camera's views of the test blade. To obtain a more complete mapping of the surface temperatures, researchers at the NASA Glenn Research Center fabricated a probe with an infrared detector to sense the blade temperatures. The probe size was kept small to minimize the flow disturbance. By traversing and rotating the probe, using the same approach as for total pressure surveys, one can find the blade surface temperatures. Probe mounted infrared detectors are appropriate for measuring surface temperatures where an externally positioned infrared camera is unable to completely view the test object. This probe consists of a 8-mm gallium arsenide (GaAs) lens mounted in front of a mercury-cadmium-zinc-tellurium (HgCdZnTe) detector. This type of photovoltaic detector was chosen because of its high sensitivity to temperature when the detector is uncooled. The particular application is for relatively low surface temperatures, typically ambient to 100 C. This requires a detector sensitive at long wavelengths. The detector is a commercial product enclosed in a 9-mm-diameter package. The GaAs lens material was chosen because of its glass-like hardness and its good long-wavelength transmission characteristics. When assembled, the 6.4-mm probe stem is held in the traversing actuator. Since the entire probe is above the measurement plane, the flow field disturbance in the measurement plane is minimized. This particular probe body is somewhat wider than necessary, because it was designed to have replaceable detectors and lenses. The signal for the detector is

  12. STUDY ON INFRARED PBS DETECTOR PREPARED USING COPPER ELECTRODES OF PRINTED CIRCUIT BOARD

    Directory of Open Access Journals (Sweden)

    Hariyadi Soetedjo

    2013-01-01

    Full Text Available Copper layers of Printed Circuit Board (PCB have been used as electrodes for PbS infrared structure detector to introduce low cost and simple in preparation. PbS deposition as an active layer detector has been prepared for a few micrometers in thickness using an evaporation technique under vacuum pressure at 10-6 Torr. Photoconductivity phenomenon has been observed from the measurement when IR radiation of a Tungsten lamp introduced to the detector. The sensitivity of the detector respects to the variation of radiation intensities was also observed. The results showed that the detector has good sensitivity indicated by rapid drop voltages at a short-wavelength IR region (1-3 µm. This phenomenon is encouraging for further applications of detector prepared using the electrodes from a commercialized PCB.

  13. Passively-Cooled Hyperspectral Infrared Detectors and Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A constant demand exists to improve the sensitivity of trace chemical species measurement systems, which is often limited by the performance of the infrared photon...

  14. Mid-infrared pyro-resistive graphene detector on LiNbO3

    CERN Document Server

    Gopalan, Kavitha K; Nanot, Sebastien; Parret, Romain; Lundeberg, Mark B; Koppens, Frank H L; Pruneri, Valerio

    2016-01-01

    Mid-infrared (mid-IR) photo-detection has been recently growing in importance because of its multiple applications, including vibrational spectroscopy and thermal imaging. We propose and demonstrate a novel pyro-resistive photo-detection platform that combines a ferroelectric substrate (a z-cut LiNbO3 crystal) and a graphene layer transferred on top of its surface with electrical connections. Upon strong light absorption in the LiNbO3 substrate and the subsequent temperature increase, via the pyroelectric effect, polarization (bound) charges form at the crystal surface. These causes doping into graphene which in turn changes its carrier density and conductivity. In this way, by monitoring the graphene electrical resistance one can measure the incident optical power. . Detectivities of about 10^5 cm sqrt(Hz)/W in the 6 to 10 microns wavelength region are demonstrated.We explain the underlying physical mechanism of the pyro-resistive photo-detection and propose a model that reproduces accurately the experimenta...

  15. Pyroelectric Harvesters for Generating Cyclic Energy

    Directory of Open Access Journals (Sweden)

    Chun-Ching Hsiao

    2015-04-01

    Full Text Available Pyroelectric energy conversion is a novel energy process which directly transforms waste heat energy from cyclic heating into electricity via the pyroelectric effect. Application of a periodic temperature profile to pyroelectric cells is necessary to achieve temperature variation rates for generating an electrical output. The critical consideration in the periodic temperature profile is the frequency or work cycle which is related to the properties and dimensions of the air layer; radiation power and material properties, as well as the dimensions and structure of the pyroelectric cells. This article aims to optimize pyroelectric harvesters by matching all these requirements. The optimal induced charge per period increases about 157% and the efficient period band decreases about 77%, when the thickness of the PZT cell decreases from 200 μm to 50 μm, about a 75% reduction. Moreover, when using the thinner PZT cell for harvesting the pyroelectric energy it is not easy to focus on a narrow band with the efficient period. However, the optimal output voltage and stored energy per period decrease about 50% and 74%, respectively, because the electrical capacitance of the 50 μm thick pyroelectric cell is about four times greater than that of the 200 μm thick pyroelectric cell. In addition, an experiment is used to verify that the work cycle to be able to critically affect the efficiency of PZT pyroelectric harvesters. Periods in the range between 3.6 s and 12.2 s are useful for harvesting thermal cyclic energy by pyroelectricity. The optimal frequency or work cycle can be applied in the design of a rotating shutter in order to control the heated and unheated periods of the pyroelectric cells to further enhance the amount of stored energy.

  16. Miniature Uncooled Infrared Sensitive Detectors for in Vivo Biomedical Imaging Applications

    Energy Technology Data Exchange (ETDEWEB)

    Datskos, P. G.; Demos, S. G.; Rajic, S.

    1998-06-01

    Broadband infrared (OR) radiation detectors have been developed using miniature, inexpensive, mass produced microcantilevers capable of detecting temperature differences as small as lea(-6) K. Microcantilevers made out of semiconductor materials can be used either as uncurled photon or thermal detectors. Mounted on a probe mm in diameter a number of microcantilevers can be accommodated in the working channel of existing endoscopes for in vivo proximity focus measurements inside the human body.

  17. Physics and Applications of Unipolar Barriers in Infrared (IR) Detectors

    Science.gov (United States)

    2016-08-23

    Minerals , Metals & Materials Society 466325 Approved for public release; distribution is unlimited. Appendix E considers the general limitations of...shares the same spatial makeup as the photocurrent.16 Therefore, under the condition that the absorbing layer of a detector must be doped to have the

  18. Pyroelectric Energy Harvesting: Model and Experiments

    Science.gov (United States)

    2016-05-01

    characterization of the pyroelectric sample was performed with a Radiant Precision Premier II Ferroelectric Tester. The Radiant Vision software...enables many electrical measurements including ferroelectric hysteresis loops, leakage, and capacitance tests. The Radiant system uses a current...conversion cycles. 5.1 Static Testing The pyroelectric sample was tested under static temperature conditions using the heater element and a Radiant

  19. JWST Near-Infrared Detector Degradation: Finding the Problem, Fixing the Problem, and Moving Forward

    Science.gov (United States)

    Rauscher, Bernard J.; Stahle, Carl; Hill, Bob; Greenhouse, Matt; Beletic, James; Babu, Sachidananda; Blake, Peter; Cleveland, Keith; Cofie, Emmanuel; Eegholm, Bente; Engelbracht, Chad; Hall, Don; Hoffman, Alan; Jeffers, Basil; Jhabvala, Christine; Kimble, Randy; Kopp, Robert; Lee, Don; Leidecker, Henning; Lindler, Don; McMurray, Bob; Mott, D. Brent; Ohl, Ray; Polis, Don; Pontius, Jim

    2012-01-01

    The James Webb Space Telescope (JWST) is the successor to the Hubble Space Telescope. JWST will be an infrared optimized telescope, with an approximately 6.5 m diameter primary mirror, that is located at the Sun-Earth L2 Lagrange point. Three of JWST's four science instruments use Teledyne HgCdTe HAWAII-2RG (H2RG) near infrared detector arrays. During 2010, the JWST Project noticed that a few of its 5 micron cutoff H2RG detectors were degrading during room temperature storage, and NASA chartered a "Detector Degradation Failure Review Board" (DD-FRB) to investigate. The DD-FRB determined that the root cause was a design flaw that allowed indium to interdiffuse with the gold contacts and migrate into the HgCdTe detector layer. Fortunately, Teledyne already had an improved design that eliminated this degradation mechanism. During early 2012, the improved H2RG design was qualified for flight and JWST began making additional H2RGs. In this article we present the two public DD-FRB "Executiye Summaries" that: (1) determined the root cause of the detector degradation and (2) defined tests to determine whether the existing detectors are qualified for flight. We supplement these with a brief introduction to H2RG detector arrays, and a discussion of how the JWST Project is using cryogenic storage to retard the degradation rate of the existing flight spare H2RGs.

  20. Piezoelectric and pyroelectric properties of lead titanate-polyethylene oxide composites

    NARCIS (Netherlands)

    Khanbareh, H.; van der Zwaag, S.; Groen, W. A.

    2014-01-01

    Polymer-ceramic composites with pyroelectric sensitivity are presented as promising candidates for infrared detection. Selection of the appropriate ceramic filler and the polymer matrix is one of the key parameters in the development of optimized materials for specific applications. In this work lea

  1. The Numerical-Experimental Enhanced Analysis of HOT MCT Barrier Infrared Detectors

    Science.gov (United States)

    Jóźwikowski, K.; Piotrowski, J.; Jóźwikowska, A.; Kopytko, M.; Martyniuk, P.; Gawron, W.; Madejczyk, P.; Kowalewski, A.; Markowska, O.; Martyniuk, A.; Rogalski, A.

    2017-04-01

    We present the results of numerical simulations and experimental data of band gap-engineered higher operating temperature mercury cadmium telluride barrier photodiodes working in a middle wavelength infrared radiation and a long wavelength infrared radiation range of an infrared radiation spectrum. Detailed numerical calculations of the detector performance were made with our own computer software taking into account Shockley Hall Read, Auger, band-to-band and trap-assisted tunneling and dislocation-related currents. We have also simulated a fluctuation phenomena by using our Langevin-like numerical method to analyze shot, diffusion, generation-recombination and 1/f noise.

  2. Reduced graphene oxide film based highly responsive infrared detector

    Science.gov (United States)

    Khan, Mustaque A.; Nanda, Karuna K.; Krupanidhi, Saluru B.

    2017-08-01

    Due to the unique optical properties, graphene can effectively be used for the detection of infrared light. In this regard, reduced graphene oxide (RGO) has drawn considerable attention in scientific society because of simplicity of preparation and tunable properties. Here, we report the synthesis of RGO by solvothermal reduction of graphene oxide (GO) in ethanol and the detection of infrared light (1064 and 1550 nm) with metal—RGO—metal configuration. We have observed that photocurrent, responsivity as well as the external quantum efficiency increase with C/O ratio. The responsivity value in near-infrared region can be as high as 1.34 A · W-1 and the external quantum efficiency is more than 100%. Response times of these devices are in the order of few seconds. Overall, the responsivity of our device is found to be better than many of the already reported values where graphene or reduced graphene oxide is the only active material. The high value of quantum efficiency is due to strong light absorption and the presence of mid-gap states band in RGOs.

  3. Improvement of Infrared Detectors for Tissue Oximetry using Black Silicon Nanostructures

    DEFF Research Database (Denmark)

    Petersen, Søren Dahl; Davidsen, Rasmus Schmidt; Alcala, Lucia R.;

    2014-01-01

    We present a nanostructured surface, made of dry etched black silicon, which lowers the reflectance for light incident at all angles. This surface is fabricated on infrared detectors used for tissue oximetry, where the detection of weak diffuse light signals is important. Monte Carlo simulations...

  4. A near-infrared 64-pixel superconducting nanowire single photon detector array with integrated multiplexed readout

    Energy Technology Data Exchange (ETDEWEB)

    Allman, M. S., E-mail: shane.allman@boulder.nist.gov; Verma, V. B.; Stevens, M.; Gerrits, T.; Horansky, R. D.; Lita, A. E.; Mirin, R.; Nam, S. W. [National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305-3328 (United States); Marsili, F.; Beyer, A.; Shaw, M. D. [Jet Propulsion Laboratory, 4800 Oak Grove Dr., Pasadena, California 91109 (United States); Kumor, D. [Purdue University, 610 Purdue Mall, West Lafayette, Indiana 47907 (United States)

    2015-05-11

    We demonstrate a 64-pixel free-space-coupled array of superconducting nanowire single photon detectors optimized for high detection efficiency in the near-infrared range. An integrated, readily scalable, multiplexed readout scheme is employed to reduce the number of readout lines to 16. The cryogenic, optical, and electronic packaging to read out the array as well as characterization measurements are discussed.

  5. A Near-Infrared 64-pixel Superconducting Nanowire Single Photon Detector Array with Integrated Multiplexed Readout

    CERN Document Server

    Allman, M S; Stevens, M; Gerrits, T; Horansky, R D; Lita, A E; Marsili, F; Beyer, A; Shaw, M D; Kumor, D; Mirin, R; Nam, S W

    2015-01-01

    We demonstrate a 64-pixel free-space-coupled array of superconducting nanowire single photon detectors optimized for high detection efficiency in the near-infrared range. An integrated, readily scalable, multiplexed readout scheme is employed to reduce the number of readout lines to 16. The cryogenic, optical, and electronic packaging to read out the array, as well as characterization measurements are discussed.

  6. Status of Uncooled Infrared Detector Technology at ULIS, France

    Directory of Open Access Journals (Sweden)

    J.L. Tissot

    2013-12-01

    Full Text Available The high level of accumulated expertise by ULIS and CEA/LETI on uncooled microbolometers made from amorphous silicon enables ULIS to develop uncooled IRFPA with 17 µm pixel-pitch to enable the development of small power, small weight and power (SWaP and high performance IR systems. Key characteristics of amorphous silicon based uncooled IR detector is described to highlight the advantage of this technology for system operation. A full range of products from 160 x 120 to 1024 x 768 has been developed and we will focus the paper on the ¼ VGA with 17 µm pixel pitch. Readout integrated circuit (ROIC architecture is described highlighting innovations that are widely on-chip implemented to enable an easier operation by the user. The detector configuration (integration time, windowing, gain, scanning direction, is driven by a standard I²C link. Like most of the visible arrays, the detector adopts the HSYNC/VSYNC free-run mode of operation driven with only one master clock (MC supplied to the ROIC which feeds back pixel, line and frame synchronisation. On-chip PROM memory for customer operational condition storage is available for detector characteristics. Low power consumption has been taken into account and less than 60 mW is possible in analogue mode at 60 Hz. A wide electrical dynamic range (2.4V is maintained despite the use of advanced CMOS node. The specific appeal of this unit lies in the high uniformity and easy operation it provides. The reduction of the pixel-pitch turns this TEC-less ¼ VGA array into a product well adapted for high resolution and compact systems. Noise equivalent temperature difference (NETD of 35 mK and thermal time constant of 10 ms have been measured leading to 350 mK.ms figure of merit. We insist on NETD trade-off with wide thermal dynamic range, as well as the high characteristics uniformity and pixel operability, achieved thanks to the mastering of the amorphous silicon technology coupled with the ROIC design

  7. Pyroelectric energy conversion: optimization principles.

    Science.gov (United States)

    Sebald, Gael; Lefeuvre, Elie; Guyomar, Daniel

    2008-03-01

    In the framework of microgenerators, we present in this paper the key points for energy harvesting from temperature using ferroelectric materials. Thermoelectric devices profit from temperature spatial gradients, whereas ferroelectric materials require temporal fluctuation of temperature, thus leading to different applications targets. Ferroelectric materials may harvest perfectly the available thermal energy whatever the materials properties (limited by Carnot conversion efficiency) whereas thermoelectric material's efficiency is limited by materials properties (ZT figure of merit). However, it is shown that the necessary electric fields for Carnot cycles are far beyond the breakdown limit of bulk ferroelectric materials. Thin films may be an excellent solution for rising up to ultra-high electric fields and outstanding efficiency. Different thermodynamic cycles are presented in the paper: principles, advantages, and drawbacks. Using the Carnot cycle, the harvested energy would be independent of materials properties. However, using more realistic cycles, the energy conversion effectiveness remains dependent on the materials properties as discussed in the paper. A particular coupling factor is defined to quantify and check the effectiveness of pyroelectric energy harvesting. It is defined similarly to an electromechanical coupling factor as k2=p2theta0/(epsilontheta33cE), where p, theta0, epsilontheta33, cE are pyroelectric coefficient, maximum working temperature, dielectric permittivity, and specific heat, respectively. The importance of the electrothermal coupling factor is shown and discussed as an energy harvesting figure of merit. It gives the effectiveness of all techniques of energy harvesting (except the Carnot cycle). It is finally shown that we could reach very high efficiency using 1110.75Pb(Mg1/3Nb2/3)-0.25PbTiO3 single crystals and synchronized switch harvesting on inductor (almost 50% of Carnot efficiency). Finally, practical implementation key

  8. Thermophysics modeling of an infrared detector cryochamber for transient operational scenario

    Science.gov (United States)

    Singhal, Mayank; Singhal, Gaurav; Verma, Avinash C.; Kumar, Sushil; Singh, Manmohan

    2016-05-01

    An infrared detector (IR) is essentially a transducer capable of converting radiant energy in the infrared regime into a measurable form. The benefit of infrared radiation is that it facilitates viewing objects in dark or through obscured conditions by detecting the infrared energy emitted by them. One of the most significant applications of IR detector systems is for target acquisition and tracking of projectile systems. IR detectors also find widespread applications in the industry and commercial market. The performance of infrared detector is sensitive to temperatures and performs best when cooled to cryogenic temperatures in the range of nearly 120 K. However, the necessity to operate in such cryogenic regimes increases the complexity in the application of IR detectors. This entails a need for detailed thermophysics analysis to be able to determine the actual cooling load specific to the application and also due to its interaction with the environment. This will enable design of most appropriate cooling methodologies suitable for specific scenarios. The focus of the present work is to develop a robust thermo-physical numerical methodology for predicting IR cryochamber behavior under transient conditions, which is the most critical scenario, taking into account all relevant heat loads including radiation in its original form. The advantage of the developed code against existing commercial software (COMSOL, ANSYS, etc.), is that it is capable of handling gas conduction together with radiation terms effectively, employing a ubiquitous software such as MATLAB. Also, it requires much smaller computational resources and is significantly less time intensive. It provides physically correct results enabling thermal characterization of cryochamber geometry in conjunction with appropriate cooling methodology. The code has been subsequently validated experimentally as the observed cooling characteristics are found to be in close agreement with the results predicted using

  9. Thermal cycling reliability of indirect hybrid HgCdTe infrared detectors

    Science.gov (United States)

    Chen, Xing; He, Kai; Wang, Jian-xin; Zhang, Qin-yao

    2013-09-01

    Thermal cycling reliability is one of the most important issues whether the HgCdTe infrared focal plane array detectors can be applied to both military and civil fields. In this paper, a 3D finite element model for indirect hybrid HgCdTe infrared detectors is established. The thermal stress distribution and thermally induced warpage of the detector assembly as a function of the distance between the detector chip and Si-ROIC, the thickness and the materials properties of electrical lead board in cryogenic temperature are analyzed. The results show that all these parameters have influences on the thermal stress distribution and warpage of the detector assembly, especially the coefficient of thermal expansion(CTE) of electrical lead board. The thermal stress and warpage in the assembly can be avoided or minimized by choosing the appropriate electrical lead board. Additionally, the warpage of some indirect hybrid detectors assembly samples is measured in experiment. The experimental results are in good agreement with the simulation results, which verifies that the results are calculated by finite element method are reasonable.

  10. An Infrared Laser Testing Facility for the Characterization of the CLAS12 Silicon Detectors

    Science.gov (United States)

    Phillips, Sarah

    2011-04-01

    During the 12 GeV upgrade to the CEBAF accelerator at Jefferson Lab, a new spectrometer, CLAS12, will be built in Hall B. The Nuclear Physics Group at the University of New Hampshire is part of the collaboration working to design and build this new detector system. Among the new detector systems being developed for CLAS12 is a silicon vertex tracker that will be placed close to the target, providing excellent position resolution for vertex determination. It is essential to have the ability to perform quality assurance tests and to evaluate the performance of the individual silicon strip detectors before their installation in the full detector system. The UNH Nuclear Physics Group is designing and building a laser testing facility at UNH to perform this task. The design for the testing facility consists of a 1064 nm infrared laser system and a precision positioning mechanism to scan the laser light on the detector by a computer controlled system designed to efficiently test the large number of detectors prior to installation. The detector signals are read out by a computer data acquisition system for analysis. The facility also includes a cleanroom area to house the test stand, and a dry storage containment system for the storage of the detectors.

  11. Photoluminescence Study of Long Wavelength Superlattice Infrared Detectors

    Science.gov (United States)

    Hoglund, Linda; Khoshakhlagh, Arezou; Soibel, Alexander; Ting, David Z.; Hill, Cory J.; Keo, Sam; Gunapala, Sarath D.

    2011-01-01

    In this paper, the relation between the photoluminescence (PL) intensity and the PL peak wavelength was studied. A linear decrease of the PL intensity with increasing cut-off wavelength of long wavelength infrared CBIRDs was observed at 77 K and the trend remained unchanged in the temperature range 10 - 77 K. This relation between the PL intensity and the peak wavelength can be favorably used for comparison of the optical quality of samples with different PL peak wavelengths. A strong increase of the width of the PL spectrum in the studied temperature interval was observed, which was attributed to thermal broadening.

  12. The pyroelectric constant and dielectric coefficient measurement of pyroelectric thin films

    CERN Document Server

    Altintas, E

    1998-01-01

    Pyroelectric coefficient measurements were made in various temperature for poled and unpoled form of PVDF which is pyroelectric material. For these experiments the quasi-static techniques was used. PVDF samples were poled in various electric strengths and relation between poling field strength and pyroelectric coefficient was investigated. It was observed that as poling field strength was increased, the pyroelectric coefficient increased as well. The other study was the effect of poling temperature on pyroelectricity. The best result was obtained when PVDF sample was poled at 340 K. This temperature value is about the Curie temperature of PVDF is and given in the literature. For poled and unpoled samples, there was an increase in pyroelectric coefficient with the increase of measurement temperature up to T sub c. The dielectric permittivity and dielectric loss measurement of PVDF which is a semi-crystalline polymer was taken in the 125-375 K temperature and 100-20 khz frequency interval. The measurements show...

  13. Wind-driven pyroelectric energy harvesting device

    Science.gov (United States)

    Xie, Mengying; Zabek, Daniel; Bowen, Chris; Abdelmageed, Mostafa; Arafa, Mustafa

    2016-12-01

    Pyroelectric materials have recently received attention for harvesting waste heat owing to their potential to convert temperature fluctuations into useful electrical energy. One of the main challenges in designing pyroelectric energy harvesters is to provide a means to induce a temporal heat variation in a pyroelectric material autonomously from a steady heat source. To address this issue, we propose a new form of wind-driven pyroelectric energy harvester, in which a propeller is set in rotational motion by an incoming wind stream. The speed of the propeller’s shaft is reduced by a gearbox to drive a slider-crank mechanism, in which a pyroelectric material is placed on the slider. Thermal cycling is obtained as the reciprocating slider moves the pyroelectric material across alternative hot and cold zones created by a stationary heat lamp and ambient temperature, respectively. The open-circuit voltage and closed-circuit current are investigated in the time domain at various wind speeds. The device was experimentally tested under wind speeds ranging from 1.1 to 1.6 m s-1 and charged an external 100 nF capacitor through a signal conditioning circuit to demonstrate its effectiveness for energy harvesting. Unlike conventional wind turbines, the energy harvested by the pyroelectric material is decoupled from the wind flow and no mechanical power is drawn from the transmission; hence the system can operate at low wind speeds (<2 m s-1).

  14. Design of MWIR Type-II Superlattices for Infrared Photon Detectors

    Science.gov (United States)

    Grein, Christoph

    The Type II InAs/GaInSb and InAs/InAsSb superlattices are material systems for implementation as photodetector absorbers in infrared imaging applications. In addition to cutoff wavelengths spanning the infrared spectrum, they offer degrees of freedom in their materials design (e.g. layer thicknesses, alloy compositions, number of layers in one superlattice period) that permit the optimization of an infrared photon detector's figures of merit such as detectivity through the tuning of material properties like generation/recombination lifetimes and optical absorption. We describe efforts to obtain accurate electronic band structures of superlattice semiconductors with infrared energy gaps, and employing them to evaluate nonradiative minority carrier lifetimes. Simple device models are utilized to suggest potential performance enhancements that arise from employing superlattices as infrared absorber. We also discuss current efforts to simulate the molecular beam epitaxial growth of InAs/InAsSb superlattices to predict dominant native point defects and other growth nonidealities. Design of MWIR Type-II Superlattices for Infrared Photon Detectors.

  15. 32 Bin Near-Infrared Time-Multiplexing Detector with Attojoule Single-Shot Energy Resolution

    CERN Document Server

    Eraerds, Patrick; Pomarico, Enrico; Sanguinetti, Bruno; Thew, Rob; Zbinden, Hugo

    2010-01-01

    We present two implementations of photon counting time-multiplexing detectors for near-infrared wavelengths, based on Peltier cooled InGaAs/InP avalanche photo diodes (APDs). A first implementation is motivated by practical considerations using only commercially available components. It features 16 bins, pulse repetition rates of up to 22 kHz and a large range of applicable pulse widths of up to 100 ns. A second implementation is based on rapid gating detectors, permitting deadtimes below 10 ns. This allows one to realize a high dynamic-range 32 bin detector, able to process pulse repetition rates of up to 6 MHz for pulse width of up to 200 ps. Analysis of the detector response at 16.5% detection efficiency, reveals a single-shot energy resolution on the attojoule level.

  16. Virtual experiment of pyroelectric fusion

    Energy Technology Data Exchange (ETDEWEB)

    Nasseri, Mohammad Mehdi, E-mail: mnasseri@aeoi.org.ir

    2015-11-01

    The virtual experiment of pyroelectric fusion was conducted by Geant4 simulator. Despite the limitations of the code for simulating the pyroelectric fusion experiment precisely, the following interesting results were obtained. Two crystals were separated by a certain distance. A constant electric field with varying intensities was applied between the crystals. As initial particles, deuterium ions were emitted to deuterated polypropylene (CD{sub 2}). This virtual experiment showed that the number of ions that hit the target, for different distances between the crystals, increases with the increase of the intensity of the electric field; however, further increase of the electric field results in the reduction of the number of hit ions, which attains a constant value of about 57% of the initial number of ions. For a (D, D) fusion reaction to occur, the distance between the two crystals should be <1.5 cm and for a (D, T) fusion reaction to occur, this distance could be up to 2 cm. The energy spectra of ions for low and high electric fields were narrow and long and wide and short, respectively.

  17. High-resolution infrared detector and its electronic unit for space application

    Science.gov (United States)

    Meftah, M.; Montmessin, F.; Korablev, O.; Trokhimovsky, A.; Poiet, G.; Bel, J.-B.

    2015-05-01

    High-resolution infrared detector is used extensively for military and civilian purposes. Military applications include target acquisition, surveillance, night vision, and tracking. Civilian applications include, among others, scientific observations. For our space systems, we want to use the products developed by SOFRADIR Company. Thus, we have developed a space electronic unit that is used to control the high-resolution SCORPIO-MW infrared detector, which has a format of 640×512 pixels with 15μm×15μm pixel pitch. The detector within microelectronics based on infrared mid-wave (MW) complementary metal oxide semiconductors (CMOS) uses a micro-cooler in order to keep its temperature around 100 K. The standard wavelength range (3 to 5μm) is adapted to the 2.2 to 4.3μm wavelength range thanks to adaptation of the optical interface of the detector and with an antireflection coating. With our electronic system, we can acquire 3 images per second. To increase the signal to noise ratio, we have the opportunity to make a summation of 15 frames per image. Through this article, we will describe the space electronic system that we have developed in order to achieve space observations (e.g. Atmospheric Chemistry Suite package for ExoMars Trace Gas Orbiter).

  18. A new generation of small pixel pitch/SWaP cooled infrared detectors

    Science.gov (United States)

    Espuno, L.; Pacaud, O.; Reibel, Y.; Rubaldo, L.; Kerlain, A.; Péré-Laperne, N.; Dariel, A.; Roumegoux, J.; Brunner, A.; Kessler, A.; Gravrand, O.; Castelein, P.

    2015-10-01

    Following clear technological trends, the cooled IR detectors market is now in demand for smaller, more efficient and higher performance products. This demand pushes products developments towards constant innovations on detectors, read-out circuits, proximity electronics boards, and coolers. Sofradir was first to show a 10μm focal plane array (FPA) at DSS 2012, and announced the DAPHNIS 10μm product line back in 2014. This pixel pitch is a key enabler for infrared detectors with increased resolution. Sofradir recently achieved outstanding products demonstrations at this pixel pitch, which clearly demonstrate the benefits of adopting 10μm pixel pitch focal plane array-based detectors. Both HD and XGA Daphnis 10μm products also benefit from a global video datapath efficiency improvement by transitioning to digital video interfaces. Moreover, innovative smart pixels functionalities drastically increase product versatility. In addition to this strong push towards a higher pixels density, Sofradir acknowledges the need for smaller and lower power cooled infrared detector. Together with straightforward system interfaces and better overall performances, latest technological advances on SWAP-C (Size, Weight, Power and Cost) Sofradir products enable the advent of a new generation of high performance portable and agile systems (handheld thermal imagers, unmanned aerial vehicles, light gimbals etc...). This paper focuses on those features and performances that can make an actual difference in the field.

  19. Hetero-engineering infrared detectors with type-II superlattices

    Science.gov (United States)

    Tian, Z.-B.; DeCuir, E. A.; Gautam, N.; Krishna, S.; Wijewarnasuriya, P. S.; Pattison, J. W.; Dhar, N.; Welser, R. E.; Sood, A. K.

    2013-09-01

    InAs/GaSb type-II superlattices (T2-SLs) are of great interest as they provide a lot of band engineering flexibility. A wide variety of unipolar barrier structures have been investigated with this material system. In this report, we will present our recent work on the development of low noise long-wave infrared (LWIR) InAs/GaSb T2-SLs photodetectors. By adopting a so-called pBiBn design, the dark current of LWIR photodetectors is greatly suppressed. The LWIR pBiBn device has demonstrated a dark current density as low as 1.42×10-5 A/cm2 at -60 mV, and R0A of 5365 Ωcm2 at 76 K. A peak detectivity at 7.8 μm of 7.7×1011 cmHz1/2W-1 is obtained at 76 K. Further effort to reduce the operating bias is also reported. By refining the energy-band alignment, a 2-μm-thick LWIR pBiBn device has demonstrated a single pass (no AR coating) quantum efficiency of 20% at 10 μm under zero-bias at 77 K. We have recently extended our efforts to further reduce the dark current by using an interband cascade (IC) photodetector structure. Some further details about the device operation and results will be discussed.

  20. Optical readout uncooled infrared imaging detector using knife-edge filter operation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Q; MIAO Z; GUO Z; DONG F; XIONG Z; WU X; CHEN D; LI C; JIAO B

    2007-01-01

    An optical readout uncooled infrared (IR) imaging detector of bimaterial cantilever array using knife-edge filter operation(KEFO) is demonstrated. The angle change of each cantilever in a focal plane array (FPA) can be simultaneously detected with a resolution of 10-5 degree. A deformation magnifying substrate-free micro-cantilever unit with multi-fold interval metallized legs is specially designed and modeled. A FPA with 160× 160 pixels is fabricated and thermal images with noise equivalent temperature difference (NETD) of 400 mK are obtained by this imaging detector.

  1. Single-photon source characterization with infrared-sensitive superconducting single-photon detectors

    CERN Document Server

    Hadfield, R H; Nam, S W; Stevens, M J; Hadfield, Robert H.; Mirin, Richard P.; Nam, Sae Woo; Stevens, Martin J.

    2006-01-01

    Single-photon sources and detectors are key enabling technologies in quantum information processing. Nanowire-based superconducting single-photon detectors (SSPDs) offer single-photon detection from the visible well into the infrared with low dark counts, low jitter and short dead times. We report on the high fidelity characterization (via antibunching and spontaneous emission lifetime measurements) of a cavity-coupled single-photon source at 902 nm using a pair of SSPDs. The twin SSPD scheme reported here is well-suited to the characterization of single-photon sources at telecom wavelengths (1310 nm, 1550 nm).

  2. Nanopillar optical antenna nBn detectors for subwavelength infrared pixels

    Science.gov (United States)

    Hung, Chung Hong; Senanayake, Pradeep; Lee, Wook-Jae; Farrell, Alan; Hsieh, Nick; Huffaker, Diana L.

    2015-06-01

    The size, weight and power (SWaP) of state of the art infrared focal plane arrays are limited by the pixel size approaching the diffraction limit. We investigate a novel detector architecture which allows improvements in detectivity by shrinking the absorber volume while maintaining high quantum efficiency and wide field of view (FOV). It has been previously shown that the Nanopillar Optical Antenna (NOA) utilizes 3D plasmonic modes to funnel light into a subwavelength nanopillar absorber. We show detailed electro-optical simulations for the NOA-nBn architecture for overcoming generation recombination current with suitable surface passivation to achieve background limited infrared performance.

  3. Commentary: JWST near-infrared detector degradation— finding the problem, fixing the problem, and moving forward

    Directory of Open Access Journals (Sweden)

    Bernard J. Rauscher

    2012-06-01

    Full Text Available The James Webb Space Telescope (JWST is the successor to the Hubble Space Telescope. JWST will be an infrared-optimized telescope, with an approximately 6.5 m diameter primary mirror, that is located at the Sun-Earth L2 Lagrange point. Three of JWST’s four science instruments use Teledyne HgCdTe HAWAII-2RG (H2RG near infrared detector arrays. During 2010, the JWST Project noticed that a few of its 5 μm cutoff H2RG detectors were degrading during room temperature storage, and NASA chartered a “Detector Degradation Failure Review Board” (DD-FRB to investigate. The DD-FRB determined that the root cause was a design flaw that allowed indium to interdiffuse with the gold contacts and migrate into the HgCdTe detector layer. Fortunately, Teledyne already had an improved design that eliminated this degradation mechanism. During early 2012, the improved H2RG design was qualified for flight and JWST began making additional H2RGs. In this article, we present the two public DD-FRB “Executive Summaries” that: (1 determined the root cause of the detector degradation and (2 defined tests to determine whether the existing detectors are qualified for flight. We supplement these with a brief introduction to H2RG detector arrays, some recent measurements showing that the performance of the improved design meets JWST requirements, and a discussion of how the JWST Project is using cryogenic storage to retard the degradation rate of the existing flight spare H2RGs.

  4. Enhanced infrared detectors using resonant structures combined with thin type-II superlattice absorbers

    Science.gov (United States)

    Goldflam, M. D.; Kadlec, E. A.; Olson, B. V.; Klem, J. F.; Hawkins, S. D.; Parameswaran, S.; Coon, W. T.; Keeler, G. A.; Fortune, T. R.; Tauke-Pedretti, A.; Wendt, J. R.; Shaner, E. A.; Davids, P. S.; Kim, J. K.; Peters, D. W.

    2016-12-01

    We examined the spectral responsivity of a 1.77 μm thick type-II superlattice based long-wave infrared detector in combination with metallic nanoantennas. Coupling between the Fabry-Pérot cavity formed by the semiconductor layer and the resonant nanoantennas on its surface enables spectral selectivity, while also increasing peak quantum efficiency to over 50%. Electromagnetic simulations reveal that this high responsivity is a direct result of field-enhancement in the absorber layer, enabling significant absorption in spite of the absorber's subwavelength thickness. Notably, thinning of the absorbing material could ultimately yield lower photodetector noise through a reduction in dark current while improving photocarrier collection efficiency. The temperature- and incident-angle-independent spectral response observed in these devices allows for operation over a wide range of temperatures and optical systems. This detector paradigm demonstrates potential benefits to device performance with applications throughout the infrared.

  5. Modeling effects of common molecular contaminants on the Euclid infrared detectors

    Science.gov (United States)

    Holmes, W.; McKenney, C.; Barbier, R.; Cho, H.; Cillis, A.; Clemens, J.-C.; Dawson, O.; Delo, G.; Ealet, A.; Feizi, A.; Ferraro, N.; Foltz, R.; Goodsall, T.; Hickey, M.; Hwang, T.; Israelsson, U.; Jhabvala, M.; Kahle, D.; Kan, Em.; Kan, Er.; Lotkin, G.; Maciaszek, T.; McClure, S.; Miko, L.; Nguyen, L.; Pravdo, S.; Prieto, E.; Powers, T.; Seiffert, M.; Strada, P.; Tucker, C.; Turck, K.; Waczynski, A.; Wang, F.; Weber, C.; Williams, J.

    2016-07-01

    Cleanliness specifications for infrared detector arrays are usually so stringent that effects are neglibile. However, the specifications determine only the level of particulates and areal density of molecular layer on the surface, but the chemical composition of these contaminants are not specified. Here, we use a model to assess the impact on system quantum efficiency from possible contaminants that could accidentally transfer or cryopump to the detector during instrument or spacecraft testing and on orbit operation. Contaminant layers thin enough to meet typical specifications, < 0.5μgram/cm2, have a negligible effect on the net quantum efficiency of the detector, provided that the contaminant does not react with the detector surface, Performance impacts from these contaminant plating onto the surface become important for thicknesses 5 - 50μgram/cm2. Importantly, detectable change in the "ripple" of the anti reflection coating occurs at these coverages and can enhance the system quantum efficiency. This is a factor 10 less coverage for which loss from molecular absorption lines is important. Thus, should contamination be suspected during instrument test or flight, detailed modelling of the layer on the detector and response to very well known calibrations sources would be useful to determine the impact on detector performance.

  6. Characterisation of an inhomogeneously irradiated microstrip detector using a fine spot infrared laser

    Energy Technology Data Exchange (ETDEWEB)

    Casse, G. E-mail: gcasse@hep.ph.liv.ac.uk; Allport, P.P.; Biagi, S.F.; Bowcock, T.J.V.; Greenall, A.; Turner, P.R

    2003-10-11

    A prototype silicon microstrip detector with p-strip read-out on oxygen enriched n-type substrate has been non-homogeneously irradiated using a 24 GeV/c proton beam at the CERN-PS accelerator. The detector has a semicircular shape with radial strip geometry. The peak fluence received by the detector was 4.6x10{sup 14} p/cm{sup 2} though the non-uniform nature of the exposure left part of the detector unirradiated. The inhomogeneous irradiation introduced a damage profile in the detector approximating to that expected in the inner LHC region. High-irradiation gradients are important to study as they can modify the electric field within the silicon. Of special interest are changes in the component of the electric field parallel to the strip plane but perpendicular to the strips, which could lead to systematic shifts in the reconstructed cluster position. If these (flux and position dependent) shifts are sufficiently large they could contribute to degrading the spatial resolution of the detector. In order to quantify these effects, a precision narrow focus light spot from an infrared laser was used to investigate the charge collection properties of the sensor. Particular attention was devoted to the regions where a high gradient of the fluence will have introduced a large gradient in the effective local space charge. The results reported below place limits on the 'distortions' due to non-uniform irradiation.

  7. Analysis and Control of Carrier Transport in Unipolar Barrier Mid-Infrared (IR) Detectors

    Science.gov (United States)

    2017-01-03

    permission to manufacture, use, or sell any patented invention that may relate to them. This report is the result of contracted fundamental research...infrared detectors constructed of InAs-based materials. MBE growth temperature affects the quality of InAs materials, as assessed by measured ...490ºC (solid red line), measured at 15K………….3 Figure 4. (Color online) Minority carrier recombination lifetimes determined by fitting a single

  8. A Novel Multiple Component Gas Infrared Ray Sensor

    Institute of Scientific and Technical Information of China (English)

    张永怀; 周金林; 林继鹏; 刘君华

    2003-01-01

    In this paper, The principle, structure and practical application of a novel multiple component gas infrared ray sensor are discussed. The optical gas sensor, which has infrared radiation impulses input and electric single output, is composed of narrow band light filter, optical taper and pyroelectric detector array. An infrared gas analyzer with multiple component gas tested synchronously consists of the sensor, single middle infrared source, single gas cell and computer data acquire system. As compared with sensor in other infrared gas analyzer, it has many merits such as novel structure, strong anti-oscillate performance and low cost. Different gas in different measurement area can be analyzed quantitatively by replacing optical filter module easily.

  9. A new test facility for the E-ELT infrared detector program

    Science.gov (United States)

    Lizon, Jean Louis; Amico, Paola; Brinkmann, Martin; Delabre, Bernard; Finger, Gert; Guidolin, Ivan Maria; Guzman, Ronald; Hinterschuster, Renate; Ives, Derek; Klein, Barbara; Quattri, Marco

    2016-08-01

    During the development of the VLT instrumentation program, ESO acquired considerable expertise in the area of infrared detectors, their testing and optimizing their performance. This can mainly be attributed to a very competent team and most importantly to the availability of a very well suited test facility, namely, IRATEC. This test facility was designed more than 15 years ago, specifically for 1K × 1K detectors such as the Aladdin device, with a maximum field of only 30 mm square. Unfortunately, this facility is no longer suited for the testing of the new larger format detectors that are going to be used to equip the future E-ELT instruments. It is projected that over the next 20 years, there will be of the order of 50-100 very large format detectors to be procured and tested for use with E-ELT first and second generation instruments and VLT third generation instruments. For this reason ESO has initiated the in-house design and construction of a dedicated new IR detector arrays test facility: the Facility for Infrared Array Testing (FIAT). It will be possible to mount up to four 60 mm square detectors in the facility, as well as mosaics of smaller detectors. It is being designed to have a very low thermal background such that detectors with 5.3 μm cut-off material can routinely be tested. The paper introduces the most important use cases for which FIAT is designed: they range from performing routine performance measurements on acquired devices, optimization setups for custom applications (like spot scan intra-pixel response, persistence and surface reflectivity measurements), test of new complex operation modes (e.g. high speed subwindowing mode for low order sensing, flexure control, etc.) and the development of new tests and calibration procedures to support the scientific requirements of the E-ELT and to allow troubleshooting the unexpected challenges that arise when a new detector system is brought online. The facility is also being designed to minimize

  10. Numerical Device Modeling, Analysis, and Optimization of Extended-SWIR HgCdTe Infrared Detectors

    Science.gov (United States)

    Schuster, J.; DeWames, R. E.; DeCuir, E. A.; Bellotti, E.; Dhar, N.; Wijewarnasuriya, P. S.

    2016-09-01

    Imaging in the extended short-wavelength infrared (eSWIR) spectral band (1.7-3.0 μm) for astronomy applications is an area of significant interest. However, these applications require infrared detectors with extremely low dark current (less than 0.01 electrons per pixel per second for certain applications). In these detectors, sources of dark current that may limit the overall system performance are fundamental and/or defect-related mechanisms. Non-optimized growth/device processing may present material point defects within the HgCdTe bandgap leading to Shockley-Read-Hall dominated dark current. While realizing contributions to the dark current from only fundamental mechanisms should be the goal for attaining optimal device performance, it may not be readily feasible with current technology and/or resources. In this regard, the U.S. Army Research Laboratory performed physics-based, two- and three-dimensional numerical modeling of HgCdTe photovoltaic infrared detectors designed for operation in the eSWIR spectral band. The underlying impetus for this capability and study originates with a desire to reach fundamental performance limits via intelligent device design.

  11. Free-space-coupled superconducting nanowire single-photon detectors for infrared optical communications.

    Science.gov (United States)

    Bellei, Francesco; Cartwright, Alyssa P; McCaughan, Adam N; Dane, Andrew E; Najafi, Faraz; Zhao, Qingyuan; Berggren, Karl K

    2016-02-22

    This paper describes the construction of a cryostat and an optical system with a free-space coupling efficiency of 56.5% ± 3.4% to a superconducting nanowire single-photon detector (SNSPD) for infrared quantum communication and spectrum analysis. A 1K pot decreases the base temperature to T = 1.7 K from the 2.9 K reached by the cold head cooled by a pulse-tube cryocooler. The minimum spot size coupled to the detector chip was 6.6 ± 0.11 µm starting from a fiber source at wavelength, λ = 1.55 µm. We demonstrated photon counting on a detector with an 8 × 7.3 µm2 area. We measured a dark count rate of 95 ± 3.35 kcps and a system detection efficiency of 1.64% ± 0.13%. We explain the key steps that are required to improve further the coupling efficiency.

  12. Thermal imager fixed pattern noise prediction using a characterization of the infrared detector

    Science.gov (United States)

    Mariani, Paolo; Zatti, Stefano; Giunti, Claudio; Sozzi, Barbara; Guadagnoli, Emanuele; Porta, Antonio

    2014-12-01

    Cooled infrared detectors are typically characterized by well-known electro-optical parameters: responsivity, noise equivalent temperature difference, shot noise, 1/f noise, and so on. Particularly important for staring arrays is also the residual fixed pattern noise (FPN) that can be obtained after the application of the nonuniformity correction (NUC) algorithm. A direct measure of this parameter is usually hard to define because the residual FPN strongly depends, other than on the detector, on the choice of the NUC algorithm and the operative scenario. We introduce three measurable parameters: instability, nonlinearity, and a residual after a polynomial fitting of the detector response curve, and we demonstrate how they are related to the residual FPN after the application of an NUC (the relationship with three common correction algorithms is discussed). A comparison with experimental data is also presented and discussed.

  13. InSb Mid-Infrared Photon Detector for Room-Temperature Operation

    Science.gov (United States)

    Ueno, Koichiro; Gomes Camargo, Edson; Katsumata, Takashi; Goto, Hiromasa; Kuze, Naohiro; Kangawa, Yoshihiro; Kakimoto, Koichi

    2013-09-01

    We developed a small InSb mid-infrared (2-7 µm wavelength range) photon detector that operates at room temperature. The photodiode was made from (hetero epitaxial) InSb layers that were grown on a semi-insulating GaAs substrate by molecular beam epitaxy. To suppress the effects of the diffusion current of the p-i-n photodiode, we used an AlInSb barrier layer that raises the resistance of the photodiode. We also optimized the device's doping concentration and the infrared incidence window structure. These optimization steps realized high photoelectric current output in a room-temperature environment. We also increased the signal-to-noise ratio of the detector by connecting multiple photodiodes in series. The size of this detector is 1.9×2.7×0.4 mm3 and the detectivity is 2.8×108 cm Hz1/2/W at 300 K. This is a practical IR detector that can be used in general signal amplification ICs.

  14. Bismuth Oxide Thin Films Deposited on Silicon Through Pulsed Laser Ablation, for Infrared Detectors

    Science.gov (United States)

    Condurache-Bota, Simona; Constantinescu, Catalin; Tigau, Nicolae; Praisler, Mirela

    2016-12-01

    Infrared detectors are used in many human activities, from industry to military, telecommunications, environmental studies and even medicine. Bismuth oxide thin films have proved their potential for optoelectronic applications, but their uses as infrared sensors have not been thoroughly studied so far. In this paper, pulsed laser ablation of pure bismuth targets within a controlled oxygen atmosphere is proposed for the deposition of bismuth oxide films on Si (100) substrates. Crystalline films were obtained, whose uniformity depends on the deposition conditions (number of laser pulses and the use of a radio-frequency (RF) discharge of the oxygen inside the deposition chamber). The optical analysis proved that the refractive index of the films is higher than 3 and that their optical bandgap is around 1eV, recommending them for infrared applications.

  15. Pyroelectric IRFPA mosaic image acquisition system with multi channels%多通道热释电 IRFPA 图像拼接采集系统

    Institute of Scientific and Technical Information of China (English)

    程瑶

    2014-01-01

    为了实现分辨率高的大规模热释电IRFPA 探测器,设计了多路通道并行输出的读出电路。针对多路输出的热释电IRFPA探测器,依据热释电探测的时序要求,设计了图像拼接采集系统。利用外部驱动信号控制采集卡的触发及采样时钟,由斩波器同步信号判断热释电探测器的亮场及暗场信号。构造PC-DA Q虚拟仪器系统对多通道输出的热释电型IRFPA进行多路并行图像采集,并对每路图像信号进行亮、暗场判断后进行差分处理,通过软件拼接处理成一副完整的图像,最终在软件平台上显示。对实验室研制的160列×120行双通道读出及320列×120行四通道读出的热释电读出电路进行了图像采集实验,对于同样阵列大小的单通道读出探测器,双通道结构读出速度提高了1倍,四通道结构读出速度提高了3倍。通过采集成像实验验证了系统的可行性。%In order to achieve large-scale pyroelectric infrared focal plane array (IRFPA ) detec-tor with high resolution ,the readout circuit with multi-channel parallel output was designed . Based on the pyroelectric IRFPA detector of multiple-output and the pyroelectric detecting tim-ing requirements ,the system of mosaic imaging acquisition was designed .The external driving signals were used to control the trigger and sampling clock of acquisition card ,and a chopper synchronizing signal was used to judge the bright field and dark field signal of the pyroelectric detector .The system was constructed with PC-DAQ virtual instrument system to acquire multi-channel parallel image ,judge the bright and dark field for differential processing on each channel ,and display a whole image after mosaic processing on software platform .The experi-mental image acquisition of the pyroelectric readout circuit with 160 × 120 two-channels read-out and 320 × 120 four-channels readout were taken and the output signal waveform and image were

  16. Measurements of Low Frequency Noise of Infrared Photo-Detectors with Transimpedance Detection System

    Directory of Open Access Journals (Sweden)

    Ciura Łukasz

    2014-08-01

    Full Text Available The paper presents the method and results of low-frequency noise measurements of modern mid-wavelength infrared photodetectors. A type-II InAs/GaSb superlattice based detector with nBn barrier architecture is compared with a high operating temperature (HOT heterojunction HgCdTe detector. All experiments were made in the range 1 Hz - 10 kHz at various temperatures by using a transimpedance detection system, which is examined in detail. The power spectral density of the nBn’s dark current noise includes Lorentzians with different time constants while the HgCdTe photodiode has more uniform 1/f - shaped spectra. For small bias, the low-frequency noise power spectra of both devices were found to scale linearly with bias voltage squared and were connected with the fluctuations of the leakage resistance. Leakage resistance noise defines the lower noise limit of a photodetector. Other dark current components give raise to the increase of low-frequency noise above this limit. For the same voltage biasing devices, the absolute noise power densities at 1 Hz in nBn are 1 to 2 orders of magnitude lower than in a MCT HgCdTe detector. In spite of this, low-frequency performance of the HgCdTe detector at ~ 230K is still better than that of InAs/GaSb superlattice nBn detector.

  17. A Failure Mode in Dense Infrared Detector Arrays Resulting in Increased Dark Current

    Science.gov (United States)

    Pinkie, Benjamin; Bellotti, Enrico

    2016-09-01

    In this paper, we investigate a failure mode that arises in dense infrared focal plane detector arrays as a consequence of the interactions of neighboring pixels through the minority carrier profiles in the common absorber layer. We consider the situation in which one pixel in a hexagonal array becomes de-biased relative to its neighbors and show that the dark current in the six neighboring pixels increases exponentially as a function of the difference between the nominal and anomalous biases. Moreover, we show that the current increase in the six nearest-neighbor pixels is in total larger than that by which the current in the affected pixel decreases, causing a net increase in the dark current. The physical origins of this effect are explained as being due to increased lateral diffusion currents that arise as a consequence of breaking the symmetry of the minority carrier profiles. We then perform a parametric study to quantify the magnitude of this effect for a number of detector geometric parameters, operating temperatures, and spectral bands. Particularly, numerical simulations are carried out for short-, mid-, and long-wavelength HgCdTe infrared detectors operating between 77 K and 210 K. We show that this effect is most prevalent in architectures for which the lateral diffusion current is the largest component of the total dark current—high operating temperature devices with narrow epitaxial absorber thicknesses and pitches small compared to the diffusion length of minority carriers. These results could prove significant particularly for short- and mid-wave infrared detectors, which are typically designed to fit these conditions.

  18. Examination of cotton fibers and common contaminants using an infrared microscope and a focal-plane array detector

    Science.gov (United States)

    The chemical imaging of cotton fibers and common contaminants in fibers is presented. Chemical imaging was performed with an infrared microscope equipped with a Focal-Plane Array (FPA) detector. Infrared spectroscopy can provide us with information on the structure and quality of cotton fibers. In a...

  19. Comparative Performance of PLZT and PVDF Pyroelectric Sensors Used to the Thermal Characterization of Liquid Samples

    Directory of Open Access Journals (Sweden)

    Gemima Lara Hernandez

    2013-01-01

    Full Text Available Among the photothermal methods, the photopyroelectric (PPE technique is a suitable method to determine thermal properties of different kinds of samples ranging from solids to liquids and gases. Polyvinylidene difluoride (PVDF is one of the most frequently used pyroelectric sensors in PPE technique but has the disadvantage that it can be easily deformed by the sample weight. This deformation could add a piezoelectric effect to the thermal parameters assessment; also PVDF has a narrow temperature operation range when compared with ceramic pyroelectric sensors. In order to minimize possible piezoelectric effects due to sensor deformation, a ceramic of lanthanum modified lead zirconate (PLZT was used as pyroelectric sensor in the PPE technique. Then, thermal diffusivity of some liquid samples was measured, by using the PPE configuration that denominated the thermal wave resonator cavity (TWRC, with a PLZT ceramic as pyroelectric detector. The performance obtained with the proposed ceramic in the TWRC configuration was compared with that obtained with PVDF by using the same configuration.

  20. Growth and pyroelectric properties of high Curie temperature relaxor-based ferroelectric Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 ternary single crystal

    Science.gov (United States)

    Yu, Ping; Wang, Feifei; Zhou, Dan; Ge, Wenwei; Zhao, Xiangyong; Luo, Haosu; Sun, Jinglan; Meng, Xiangjian; Chu, Junhao

    2008-06-01

    To enhance the service temperature of relaxor-PbTiO3 pyroelectric single crystals, high quality ternary perovskite single crystal was grown by a modified Bridgman technique. Analyzed by x-ray fluorescence, the as-grown crystal is 0.41Pb(In1/2Nb1/2)O3-0.17Pb(Mg1/3Nb2/3)O3-0.42PbTiO3 [PIMNT(41/17/42)], which appears to be a tetragonal ferroelectric phase with relatively high Curie temperature of 253°C. It exhibits the relative permittivity of 487 and low dielectric loss of 0.3% at 50Hz and room temperature. The pyroelectric properties with a pyroelectric coefficient of 5.7×10-4C /m2K and a detectivity of 6.34×10-5Pa-1/2 would satisfy the needs of operation as a high Curie temperature material. The results show that PIMNT crystal with better temperature stability, compared with the pure PMNT single crystals, is a good candidate as an infrared detector material.

  1. Development of low-noise kinetic inductance detectors for far-infrared astrophysics

    Science.gov (United States)

    Barlis, Alyssa; Hailey-Dunsheath, Steven; Bradford, Charles M.; McKenney, Christopher; Le Duc, Henry G.; Aguirre, James

    2017-01-01

    The star formation mechanisms at work in the early universe remain one of the major unsolved problems of modern astrophysics. Many spectral lines at far-infrared wavelengths (10 μm working to develop a detector system for a far-infrared balloon-borne spectroscopic experiment using kinetic inductance detectors (KIDs), which have the potential to achieve high sensitivity, low noise levels, high multiplexing factor, and may enable future space missions. We describe the design, fabrication, and noise performance measurements of prototype detector devices targeting an optical noise equivalent power below 1 ×10-17 WHz - 1 / 2 with readout frequencies below 250 MHz. The devices consist of arrays of 45 lumped-element KID pixels patterned out of thin-film aluminum on silicon wafers. They are optically coupled to incident radiation with a set of feedhorns. We use an FPGA-based readout system to read out the response of all the pixels in the array simultaneously. This work was supported by a NASA Space Technology Research Fellowship.

  2. Real-time, continuous-wave terahertz imaging by a pyroelectric camera

    Institute of Scientific and Technical Information of China (English)

    Jun Yang; Shuangchen Ruan; Min Zhang

    2008-01-01

    Real-time, continuous-wave terahertz (THz) imaging is demonstrated. A 1.89-THz optically-pumped farinfrared laser is used as the illumination source, and a 124 × 124 element room-temperature pyroelectric camera is adopted as the detector. With this setup, THz images through various wrapping materials are shown. The results show that this imaging system has the potential applications in real-time mail and security inspection.

  3. GaAs Blocked-Impurity-Band Detectors for Far-Infrared Astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Cardozo, Benjamin Lewin

    2004-12-21

    High-purity and doped GaAs films have been grown by Liquid-phase epitaxy (LPE) for development of a blocked impurity band (BIB) detector for far-infrared radiation. The film growth process developed has resulted in the capability to grow GaAs with a net active impurity concentration below 1 x 10{sup 13} cm{sup -3}, ideal for the blocking layer of the BIB detector. The growth of n-type LPE GaAs films with donor concentrations below the metal-insulator transition, as required for the absorbing layer of a BIB detector, has been achieved. The control of the donor concentration, however, was found to be insufficient for detector production. The growth by LPE of a high-purity film onto a commercially grown vapor-phase epitaxial (VPE) n-type GaAs doped absorbing layer resulted in a BIB device that showed a significant reduction in the low-temperature dark current compared to the absorbing layer only. Extended optical response was not detected, most likely due to the high compensation of the commercially grown GaAs absorbing layer, which restricts the depletion width of the device.

  4. Fundamental Limits on the Imaging and Polarisation Properties of Far-Infrared Detectors

    Science.gov (United States)

    Thomas, Christopher N.; Withington, Stafford; Chuss, David T.; Wollack, Edward J.; Moseley, S. Harvey

    2009-01-01

    Far-infrared bolometric detectors are used extensively in ground-based and space-borne astronomy, and thus it is important to understand their optical behaviour precisely. We have studied the intensity and polarisation response of free-space bolometers, and shown that when the size of the absorber is reduced below a wavelength, the response changes from being that of a classical optical detector to that of a few-mode antenna. We have calculated the modal content of the reception patterns, and found that for any volumetric detector having a side length of less than a wavelength, three magnetic and three electric dipoles characterize the behaviour. The size of the absorber merely determines the relative strengths of the contributions. The same formalism can be applied to thin-film absorbers, where the induced current is forced to flow in a plane. In this case, one magnetic and two electric dipoles characterize the behaviour. The ability to model easily the intensity, polarisation, and straylight characteristics of electrically-small detectors will be of great value when designing high-performance polarimetric imaging arrays.

  5. GaAs Blocked-Impurity-Band Detectors for Far-Infrared Astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Cardozo, Benjamin Lewin [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    High-purity and doped GaAs films have been grown by Liquid-phase epitaxy (LPE) for development of a blocked impurity band (BIB) detector for far-infrared radiation. The film growth process developed has resulted in the capability to grow GaAs with a net active impurity concentration below 1 x 1013 cm-3, ideal for the blocking layer of the BIB detector. The growth of n-type LPE GaAs films with donor concentrations below the metal-insulator transition, as required for the absorbing layer of a BIB detector, has been achieved. The control of the donor concentration, however, was found to be insufficient for detector production. The growth by LPE of a high-purity film onto a commercially grown vapor-phase epitaxial (VPE) n-type GaAs doped absorbing layer resulted in a BIB device that showed a significant reduction in the low-temperature dark current compared to the absorbing layer only. Extended optical response was not detected, most likely due to the high compensation of the commercially grown GaAs absorbing layer, which restricts the depletion width of the device.

  6. Modeling of high-precision wavefront sensing with new generation of CMT avalanche photodiode infrared detectors.

    Science.gov (United States)

    Gousset, Silvère; Petit, Cyril; Michau, Vincent; Fusco, Thierry; Robert, Clelia

    2015-12-01

    Near-infrared wavefront sensing allows for the enhancement of sky coverage with adaptive optics. The recently developed HgCdTe avalanche photodiode arrays are promising due to their very low detector noise, but still present an imperfect cosmetic that may directly impact real-time wavefront measurements for adaptive optics and thus degrade performance in astronomical applications. We propose here a model of a Shack-Hartmann wavefront measurement in the presence of residual fixed pattern noise and defective pixels. To adjust our models, a fine characterization of such an HgCdTe array, the RAPID sensor, is proposed. The impact of the cosmetic defects on the Shack-Hartmann measurement is assessed through numerical simulations. This study provides both a new insight on the applicability of cadmium mercury telluride (CMT) avalanche photodiodes detectors for astronomical applications and criteria to specify the cosmetic qualities of future arrays.

  7. Detector Response and Beam Line Transmission Measurements with Far-Infrared Radiation

    CERN Document Server

    Grimm, O; Fröhlich, L

    2005-01-01

    Various activities at the TTF linear accelerator at DESY, Hamburg, that drives the VUV-FEL are geared towards measuring the longitudinal charge distribution of electron bunches with coherent far-infrared radiation. Examples are beam lines transporting synchrotron or transition radiation to interferometers mounted inside or outside the tunnel, and studies of single-shot grating spectrometers. All such approaches require a good understanding of the radiation generation and transport mechanism and of the detector characteristics to extract useful information on the charge distribution. Simulations and measurements of the expected transverse intensity distribution and polarization of synchrotron radiation emitted at the first bunch compressor of TTF have been performed. The transverse intensity scanning provided for the first time at DESY a visual image of the footprint of terahertz radiation. Detector response measurements have been performed at the FELIX facility, Netherlands, for wavelengths between 100-160 mi...

  8. Non-local means-based nonuniformity correction for infrared focal-plane array detectors

    Science.gov (United States)

    Yu, Hui; Zhang, Zhi-jie; Chen, Fu-sheng; Wang, Chen-sheng

    2014-11-01

    The infrared imaging systems are normally based on the infrared focal-plane array (IRFPA) which can be considered as an array of independent detectors aligned at the focal plane of the imaging system. Unfortunately, every detector on the IRFPA may have a different response to the same input infrared signal which is known as the nonuniformity problem. Then we can observe the fixed pattern noise (FPN) from the resulting images. Standard nonuniformity correction (NUC) methods need to be recalibrated after a short period of time due the temporal drift of the FPN. Scene-based nonuniformity correction (NUC) techniques eliminate the need for calibration by correction coefficients based on the scene being viewed. However, in the scene-based NUC method the problem of ghosting artifacts widely seriously decreases the image quality, which can degrade the performance of many applications such as target detection and track. This paper proposed an improved scene-based method based on the retina-like neural network approach. The method incorporates the use of non-local means (NLM) method into the estimation of the gain and the offset of each detector. This method can not only estimates the accurate correction coefficient but also restrict the ghosting artifacts efficiently. The proposed method relies on the use of NLM method which is a very successful image denoising method. And then the NLM used here can preserve the image edges efficiently and obtain a reliable spatial estimation. We tested the proposed NUC method by applying it to an IR sequence of frames. The performance of the proposed method was compared the other well-established adaptive NUC techniques.

  9. New and Better Near-Infrared Detectors for JWST Near Infrared Spectrograph

    Science.gov (United States)

    Rauscher, Bernard J.; Mott, D. Brent; Wen, Yiting; Linder, Don; Greenhouse, Matthew A.; Hill, Robert J.

    2014-01-01

    ESA and NASA recently selected two 5 m cutoff Teledyne H2RG sensor chip assemblies (SCA) for flight on the James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec). These HgCdTe SCAs incorporate Teledynes improved barrier layer design that eliminates the degradation that affected earlier JWST H2RGs(Rauscher et al. 2012a). The better indium barrier, together with other design changes, has improved the performance and reliability of JWSTs SCAs. In this article, we describe the measured performance characteristics that most directly affect scientific observations including read noise, total noise, dark current, quantum efficiency (QE), and image persistence. As part of measuring QE, we measured the quantum yield as a function of photon energy,, and found that it exceeds unity for photon energies E (2.65.2) Eg, where Eg is the HgCdTe bandgap energy. This corresponds to. 2 m for NIRSpecs 5 m cutoff HgCdTe. Our measurements agree well with a previous measurement by McCullough et al. (2008) for. 1.3. For 1.3, we find a slower increase in with photon energy than McCullough et al. did. However, and as McCullough et al. note, their two state model of the yield process is not valid for large 1.

  10. Sol-gel PZT and Mn-doped PZT thin films for pyroelectric applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Q. [Advanced Materials Group, School of Industrial and Manufactory Science, Cranfield University, Beds (United Kingdom)]. E-mail: q.zhang@cranfield.ac.uk; Whatmore, R.W. [Advanced Materials Group, School of Industrial and Manufactory Science, Cranfield University, Beds (United Kingdom)

    2001-08-07

    Thin films of ferroelectric lead zirconate titanate (PbZr{sub 0.3}Ti{sub 0.7}O{sub 3} PZT30/70) and manganese-doped lead zirconate titanate ((Pb(Zr{sub 0.3}Ti{sub 0.7}){sub 1-x}Mn{sub x})O{sub 3}, where x=0.01, PM01ZT30/70; and x=0.03, PM03ZT30/70) have been prepared using sol-gel processing techniques. These materials can be used as the pyroelectric thin films in uncooled infrared detectors. The thin films were prepared via a sol-gel route based on a hybrid solvent of methanol and ethanol with acetic acid, ethanolamine and ethylene glycol as additives. The final solution is non-moisture sensitive and stable. Films deposited on Pt/Ti/SiO{sub 2}/Si substrates and annealed on a hot plate at 500-530{sup 0}C for a few minutes were seen to fully crystallize into the required perovskite phase and showed excellent ferroelectric behaviour, demonstrated by reproducible hysteresis loops (P{sub r}=33-37 {mu}C cm{sup -2}, Ec(+)=70-100 kV cm{sup -1}, Ec(-)=-170 to -140 kV cm{sup -1}). The pyroelectric coefficient (p) was measured using the Byer-Roundy method. At 20 deg. C, p was 2.11x10{sup -4} C m{sup -2} K{sup -1} for PZT30/70, 3.00x10{sup -4} C m{sup -2} K{sup -1} for PM01ZT30/70 and 2.40x10{sup -4} C m{sup -2} K{sup -1} for PM03ZT30/70 thin films. The detectivity figure-of-merit (F{sub D}) was 1.07x10{sup -5} Pa{sup -0.5} for PZT30/70, 3.07x10{sup -5} Pa{sup -0.5} for PM01ZT30/70 and 1.07x10{sup -5} Pa{sup -0.5} for PM03ZT30/70. These figures compare well with values reported previously. (author)

  11. Materials Research of Perovskite Thin Films for Uncooled Infrared (IR) Detectors

    Science.gov (United States)

    2011-07-01

    a. spinning a liquid photoresist onto the wafer b. baking the wafer for about an hour, exposing the wafer (the mask could have several arrays on...a wafer will go through the photolithographic steps (a-c) several times (~50 times). Figure 17 shows a film grown by conventional MBE with pixels...shows a similar process using laser-induced pyroelectric activation and bump bonding to a Si fan-out. This procedure will be used to prove proof-of

  12. Infrared limb sounding of Titan with the Cassini Composite InfraRed Spectrometer: effects of the mid-IR detector spatial responses.

    Science.gov (United States)

    Nixon, Conor A; Teanby, Nicholas A; Calcutt, Simon B; Aslam, Shahid; Jennings, Donald E; Kunde, Virgil G; Flasar, F Michael; Irwin, Patrick G; Taylor, Fredric W; Glenar, David A; Smith, Michael D

    2009-04-01

    The composite infrared spectrometer (CIRS) instrument on board the Cassini Saturn orbiter employs two 1x10 HgCdTe detector arrays for mid-infrared remote sensing of Titan's and Saturn's atmospheres. In this paper we show that the real detector spatial response functions, as measured in ground testing before launch, differ significantly from idealized "boxcar" responses. We further show that neglecting this true spatial response function when modeling CIRS spectra can have a significant effect on interpretation of the data, especially in limb-sounding mode, which is frequently used for Titan science. This result has implications not just for CIRS data analysis but for other similar instrumental applications.

  13. Innovative design of a calibration mechanism for the space infrared detector

    Science.gov (United States)

    Sun, De-wei; Li, Bo; Liu, Jian-feng; Ruan, Ning-juan

    2013-09-01

    A new style calibration mechanism is designed for the infrared camera working in space. This calibration mechanism adds a locking device, which will produce magnetic force to fix the moving parts on the stage of launch. It has not been taken into account in past calibration mechanism of space infrared camera. In order to simplify structure and control system, an alnico is adopted in locking device as the source of magnetic field, which interacts with magnetic material and produces locking force. In addition, there is also a special structural design, which makes magnetic circuit closeitself to control magnetic leakage interfering with other equipment. Besides, another important component of calibration mechanism is a permanent magnet torquer. It can provide driving force for the blackbody to complete two state conversions of calibration and Non-calibration. High magnetic induction intensity and coercivity alnico is used as the stator, which will lighten the weight of torquer. On-off control strategy is selected in order to simplify the control system. Because calibration is only a temporary state, temperature rise has little influence on torquer. This setup is favorable to increase its reliability. There are guard plates on the axial direction shielding electromagnetism, also reducing magnetic leakage. Experimental investigations have been carried out to verify the feasibility and reliability of design. Result indicates the calibration mechanism can primely complete the calibration task of the space infrared detector. It has an important application value on the field of infrared detection.

  14. Energy harvesting with piezoelectric and pyroelectric materials

    CERN Document Server

    Muensit, Nantakan

    2011-01-01

    The purpose of this book is to present the current state of knowledge in the field of energy harvesting using piezoelectric and pyroelectric materials. The book is addressed to students and academics engaged in research in the fields of energy harvesting, material sciences and engineering. Scientists and engineers who are working in the area of energy conservation and renewable energy resources should find it useful as well. Explanations of fundamental physical properties such as piezoelectricity and pyroelectricity are included to aid the understanding of the non-specialist. Specific technolo

  15. The pyroelectric vidicon - Ten years on

    Science.gov (United States)

    Burgess, D.; Nixon, R.; Ritchie, J.

    1986-01-01

    A technology development status evaluation is presented for British high performance pyroelectric vidicon, IR-sensitive TV cameras, the first tubes and cameras of which were demonstrated over a decade ago. Attention is given to the improvements that had to be instituted in camera design in order to obtain optimum performance from the vidicon tubes. A rotating disk chopper and flicker processing were incorporated into the camera's design. Pyroelectric cameras have been extensively applied in industry and the police and military services for fire detection and in rescue operations.

  16. Pyroelectric coupling in thin film photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Karpov, Victor G.; Shvydka, Diana [Department of Physics and Astronomy, University of Toledo, OH (United States)

    2007-07-15

    We propose a theory of thin film photovoltaics in which one of the polycrystalline films is made of a pyroelectric material grains such as CdS. That film is shown to generate strong polarization improving the device open circuit voltage. Implications and supporting facts for the major photovoltaic types based on CdTe and CuIn(Ga)Se{sub 2} absorber layers are discussed. Band diagram of a pyroelectric (CdS) based PV junction. Arrows represent the charge carrier photo-generation. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Denoising Using Blind Source Separation for Pyroelectric Sensors

    Directory of Open Access Journals (Sweden)

    Huez Regis

    2001-01-01

    Full Text Available This paper deals with a process of denoising based on a Blind Source Separation (BSS method. This technique is inserted in an experimental device of nondestructive testing. Its excitation is a laser beam and its detectors are pyroelectric sensors. The latter are sensitive to the temperature. As they are also piezoelectric, they are particularly sensitive to the environmental noise. Therefore, it is necessary to denoise them. With this aim in view, a technique of blind source separation is implemented. One source corresponds to the incidental beam and the other sources are various noise. A judicious experimental device was designed in the laboratory. It fits to the requirements of the BSS technique, and it allows indeed a restoration of the incident signal.

  18. Pyroelectric response of lead zirconate titanate thin films on silicon: Effect of thermal stresses

    Energy Technology Data Exchange (ETDEWEB)

    Kesim, M. T.; Zhang, J.; Alpay, S. P. [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Trolier-McKinstry, S. [Department of Materials Science and Engineering and Materials Research Institute, Pennsylvania State University, Pennsylvania 16802 (United States); Mantese, J. V. [United Technologies Research Center, East Hartford, Connecticut 06118 (United States); Whatmore, R. W. [Tyndall National Institute, Lee Maltings, Dyke Parade, Cork City, County Cork (Ireland)

    2013-11-28

    Ferroelectric lead zirconate titanate [Pb(Zr{sub x}Ti{sub 1-x}O){sub 3}, (PZT x:1-x)] has received considerable interest for applications related to uncooled infrared devices due to its large pyroelectric figures of merit near room temperature, and the fact that such devices are inherently ac coupled, allowing for simplified image post processing. For ferroelectric films made by industry-standard deposition techniques, stresses develop in the PZT layer upon cooling from the processing/growth temperature due to thermal mismatch between the film and the substrate. In this study, we use a non-linear thermodynamic model to investigate the pyroelectric properties of polycrystalline PZT thin films for five different compositions (PZT 40:60, PZT 30:70, PZT 20:80, PZT 10:90, PZT 0:100) on silicon as a function of processing temperature (25–800 °C). It is shown that the in-plane thermal stresses in PZT thin films alter the out-of-plane polarization and the ferroelectric phase transformation temperature, with profound effect on the pyroelectric properties. PZT 30:70 is found to have the largest pyroelectric coefficient (0.042 μC cm{sup −2} °C{sup −1}, comparable to bulk values) at a growth temperature of 550 °C; typical to what is currently used for many deposition processes. Our results indicate that it is possible to optimize the pyroelectric response of PZT thin films by adjusting the Ti composition and the processing temperature, thereby, enabling the tailoring of material properties for optimization relative to a specific deposition process.

  19. Hole effective masses and subband splitting in type-II superlattice infrared detectors

    Science.gov (United States)

    Ting, David Z.; Soibel, Alexander; Gunapala, Sarath D.

    2016-05-01

    We explore band structure effects to help determine the suitability of n-type type-II superlattice (T2SL) absorbers for infrared detectors. It is often assumed that the exceedingly large growth-direction band-edge curvature hole effective mass in n-type long wavelength infrared (LWIR) T2SL would lead to low hole mobility and therefore low detector collection quantum efficiency. We computed the thermally averaged conductivity effective mass and show that the LWIR T2SL hole conductivity effective mass along the growth direction can be orders of magnitude smaller than the corresponding band-edge effective mass. LWIR InAs/GaSb T2SL can have significantly smaller growth-direction hole conductivity effective mass than its InAs/InAsSb counterpart. For the InAs/InAsSb T2SL, higher Sb fraction is more favorable for hole transport. Achieving long hole diffusion length becomes progressively more difficult for the InAs/InAsSb T2SL as the cutoff wavelength increases, since its growth-direction hole conductivity effective mass increases significantly with decreasing band gap. However, this is mitigated by the fact that the splitting between the top valence subbands also increases with the cutoff wavelength, leading to reduced inter-subband scattering and increased relaxation time.

  20. Free space-coupled superconducting nanowire single photon detectors for infrared optical communications

    CERN Document Server

    Bellei, Francesco; McCaughan, Adam N; Dane, Andrew E; Najafi, Faraz; Zhao, Quinyuan; Berggren, Karl K

    2015-01-01

    This paper describes the construction of a cryostat and an optical system with a free-space coupling efficiency of 56.5% +/- 3.4% to a superconducting nanowire single-photon detector (SNSPD) for infrared quantum communication and spectrum analysis. A 1K pot decreases the base temperature to T = 1.7 K from the 2.9 K reached by the cold head cooled by a pulse-tube cryocooler. The minimum spot size coupled to the detector chip was 6.6 +/- 0.11 {\\mu}m starting from a fiber source at wavelength, {\\lambda} = 1.55 {\\mu}m. We demonstrated efficient photon counting on a detector with an 8 x 7.3 {\\mu}m^2 area. We measured a dark count rate of 95 +/- 3.35 kcps and a system detection efficiency of 1.64% +/- 0.13%. We explain the key steps that are required to further improve the coupling efficiency.

  1. Progress in MOCVD growth of HgCdTe epilayers for HOT infrared detectors

    Science.gov (United States)

    Kebłowski, A.; Gawron, W.; Martyniuk, P.; Stepień, D.; Kolwas, K.; Piotrowski, J.; Madejczyk, P.; Kopytko, M.; Piotrowski, A.; Rogalski, A.

    2016-05-01

    In this paper we present progress in MOCVD growth of (100) HgCdTe epilayers achieved recently at the Institute of Applied Physics, Military University of Technology and Vigo System S.A. It is shown that MOCVD technology is an excellent tool in fabrication of different HgCdTe detector structures with a wide range of composition, donor/acceptor doping and without post grown annealing. Particular progress has been achieved in the growth of (100) HgCdTe epilayers for long wavelength infrared photoconductors operated in HOT conditions. The (100) HgCdTe photoconductor optimized for 13-μm attain detectivity equal to 6.5x109 Jones and therefore outperform its (111) counterpart. The paper also presents technological progress in fabrication of MOCVD-grown (111) HgCdTe barrier detectors. The barrier device performance is comparable with state-of-the-art of HgCdTe photodiodes. The detectivity of HgCdTe detectors is close to the value marked HgCdTe photodiodes. Dark current densities are close to the values given by "Rule 07".

  2. An infrared motion detector system for lossless real-time monitoring of animal preference tests.

    Science.gov (United States)

    Pogány, A; Heszberger, J; Szurovecz, Zita; Vincze, E; Székely, T

    2014-12-01

    Automated behavioural observations are routinely used in many fields of biology, including ethology, behavioural ecology and physiology. When preferences for certain resources are investigated, the focus is often on simple response variables, such as duration and frequency of visits to choice chambers. Here we present an automated motion detector system that use passive infrared sensors to eliminate many drawbacks of currently existing methods. Signals from the sensors are processed by a custom-built interface, and after unnecessary data is filtered by a computer software, the total time and frequency of the subject's visits to each of the choice chambers are calculated. We validate the detector system by monitoring (using the system) and in the same time video recording mating preferences of zebra finches in a four-way choice apparatus. Manual scoring of the video recordings showed very high consistency with data from the detector system both for time and for frequency of visits. Furthermore, the validation revealed that if we used micro-switches or light barriers, the most commonly applied automatic detection techniques, this would have resulted in approximately 22% less information compared to our lossless system. The system provides a low-cost alternative for monitoring animal movements, and we discuss its further applicability.

  3. Development and application of InAsP/InP quantum well infrared detector

    Science.gov (United States)

    Geetanjali, Porwal, S.; Kumar, R.; Dixit, V. K.; Sharma, T. K.; Oak, S. M.

    2016-05-01

    InAsxP1-x/InP quantum wells grown using metal organic vapor phase epitaxy are investigated for infrared detector applications. The structural parameters of the QWs are evaluated from high resolution x-ray diffraction. The electronic transition energies measured from surface photo voltage and photoconductivity confirms that these QWs can be used for fabricating IR detectors in the wide wavelength range, i.e. 0.9-1.46 µm by inter-band transitions and 7-18 µm by inter-sub-band transitions. Subsequently the functionality of one such fabricated InAsxP1-x/InPQW detector is verified by measuring the photoluminescence of suitable semiconductor quantum well structure. At the request of all authors of the paper, and with the agreement of the Proceedings Editor, an updated version of this article was published on 24 June 2016. The original version supplied to AIP Publishing contained an error in the Figures 1 and 2 where the right side of the images were cutoff. The error has been corrected in the updated and re-published article.

  4. Pyroelectric Charge Release in Rhombohedral PZT

    NARCIS (Netherlands)

    Noheda, Beatriz; Duan, Ning; Cereceda, Noé; Gonzalo, Julio A.

    1998-01-01

    A new experimental set-up controlled by computer has been made to measure the pyroelectric charge of ferroelectric materials with a relatively high conductivity at slow rates of temperature variation. It allowed us to obtain the polarisation vs. temperature behaviour of PZT with various compositions

  5. Multi-Frequency Band Pyroelectric Sensors

    Directory of Open Access Journals (Sweden)

    Chun-Ching Hsiao

    2014-11-01

    Full Text Available A methodology is proposed for designing a multi-frequency band pyroelectric sensor which can detect subjects with various frequencies or velocities. A structure with dual pyroelectric layers, consisting of a thinner sputtered ZnO layer and a thicker aerosol ZnO layer, proved helpful in the development of the proposed sensor. The thinner sputtered ZnO layer with a small thermal capacity and a rapid response accomplishes a high-frequency sensing task, while the thicker aerosol ZnO layer with a large thermal capacity and a tardy response is responsible for low-frequency sensing tasks. A multi-frequency band pyroelectric sensor is successfully designed, analyzed and fabricated in the present study. The range of the multi-frequency sensing can be estimated by means of the proposed design and analysis to match the thicknesses of the sputtered and the aerosol ZnO layers. The fabricated multi-frequency band pyroelectric sensor with a 1 μm thick sputtered ZnO layer and a 20 μm thick aerosol ZnO layer can sense a frequency band from 4000 to 40,000 Hz without tardy response and low voltage responsivity.

  6. Pyroelectric nanogenerators for harvesting thermoelectric energy.

    Science.gov (United States)

    Yang, Ya; Guo, Wenxi; Pradel, Ken C; Zhu, Guang; Zhou, Yusheng; Zhang, Yan; Hu, Youfan; Lin, Long; Wang, Zhong Lin

    2012-06-13

    Harvesting thermoelectric energy mainly relies on the Seebeck effect that utilizes a temperature difference between two ends of the device for driving the diffusion of charge carriers. However, in an environment that the temperature is spatially uniform without a gradient, the pyroelectric effect has to be the choice, which is based on the spontaneous polarization in certain anisotropic solids due to a time-dependent temperature variation. Using this effect, we experimentally demonstrate the first application of pyroelectric ZnO nanowire arrays for converting heat energy into electricity. The coupling of the pyroelectric and semiconducting properties in ZnO creates a polarization electric field and charge separation along the ZnO nanowire as a result of the time-dependent change in temperature. The fabricated nanogenerator has a good stability, and the characteristic coefficient of heat flow conversion into electricity is estimated to be ∼0.05-0.08 Vm(2)/W. Our study has the potential of using pyroelectric nanowires to convert wasted energy into electricity for powering nanodevices.

  7. Study on Pyroelectric Harvesters Integrating Solar Radiation with Wind Power

    Directory of Open Access Journals (Sweden)

    Chun-Ching Hsiao

    2015-07-01

    Full Text Available Pyroelectric harvesters use temperature fluctuations to generate electrical outputs. Solar radiation and waste heat are rich energy sources that can be harvested. Pyroelectric energy converters offer a novel and direct energy-conversion technology by transforming time-dependent temperatures directly into electricity. Moreover, the great challenge for pyroelectric energy harvesting lies in finding promising temperature variations or an alternating thermal loading in real situations. Hence, in this article, a novel pyroelectric harvester integrating solar radiation with wind power by the pyroelectric effect is proposed. Solar radiation is a thermal source, and wind is a dynamic potential. A disk generator is used for harvesting wind power. A mechanism is considered to convert the rotary energy of the disk generator to drive a shutter for generating temperature variations in pyroelectric cells using a planetary gear system. The optimal period of the pyroelectric cells is 35 s to harvest the stored energy, about 70 μJ, while the rotary velocity of the disk generator is about 31 RPM and the wind speed is about 1 m/s. In this state, the stored energy acquired from the pyroelectric harvester is about 75% more than that from the disk generator. Although the generated energy of the proposed pyroelectric harvester is less than that of the disk generator, the pyroelectric harvester plays a complementary role when the disk generator is inactive in situations of low wind speed.

  8. Possible Explanation For Multiple Electron Emission From Pyroelectric Crystals In Dilute Gases

    Science.gov (United States)

    Shafroth, Stephen; Kaleko, David; Brownridge, James

    2009-05-01

    Pyroelectric crystals such as LiNbO3 when cut perpendicular to their z axes and when heated or cooled produce strong electric fields at their surfaces. If a 4 mm dia x 10 mm crystal is immersed in a dilute gas it acts as an accelerator of electrons when the surface is negative and positive ions when the surface is positive. In both cases a focused beam results but in the electron case multiple electron peaks are observed if they are detected through a pin hole with a surface barrier detector(1). In this poster we give evidence for an explanation of this effect. (1) Brownridge, J. D., Shafroth, S. M., Trott, D. W., Stoner, B. R., and Hooke, W. M., Observation of multiple nearly monoenergetic electron production by heated pyroelectric crystals in ambient gas, Appl. Phys. Lett., 78, 1158 (2001)

  9. Measuring Io's Lava Eruption Temperatures with a Novel Infrared Detector and Digital Readout Circuit

    Science.gov (United States)

    Davies, Ashley; Gunapala, Sarath; Rafol, B., Sir; Soibel, Alexander; Ting, David Z.

    2016-10-01

    One method of determining lava eruption temperature of Io's dominant silicate lavas is by measuring radiant flux at two or more wavelengths and fitting a black-body thermal emission function. Only certain styles of volcanic activity are suitable, those where thermal emission is from a restricted range of surface temperatures close to eruption temperature. Such processes include [1] large lava fountains; [2] fountaining in lava lakes; and [3] lava tube skylights. Problems that must be overcome are (1) the cooling of the lava between data acquisitions at different wavelengths; (2) the unknown magnitude of thermal emission, which often led to detector saturation; and (3) thermal emission changing on a shorter timescale than the observation integration time. We can overcome these problems by using the HOT-BIRD detector [4] and an advanced digital readout circuit [5]. We have created an instrument model that allows different instrument parameters (including mirror diameter, number of signal splits, exposure duration, filter band pass, and optics transmissivity) to be tested so as to determine eruption detectability. We find that a short-wavelength infrared instrument on an Io flyby mission can achieve simultaneity of observations by splitting the incoming signal for all relevant eruption processes and obtain data fast enough to remove uncertainties in accurate determination of the highest lava surface temperatures exposed. Observations at 1 and 1.5 μm are sufficient to do this. Lava temperature determinations are also possible with a visible wavelength detector [3] so long as data at different wavelengths are obtained simultaneously and integration time is very short. This is especially important for examining the thermal emission from lava tube skylights [3] due to rapidly-changing viewing geometry during close flybys. References: [1] Davies et al., 2001, JGR, 106, 33079-33104. [2] Davies et al., 2011, GRL, 38, L21308. [3] Davies et al., 2016, Icarus, in press. [4

  10. Improvement of Pyroelectric Cells for Thermal Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Jing-Chih Ciou

    2012-01-01

    Full Text Available This study proposes trenching piezoelectric (PZT material in a thicker PZT pyroelectric cell to improve the temperature variation rate to enhance the efficiency of thermal energy-harvesting conversion by pyroelectricity. A thicker pyroelectric cell is beneficial in generating electricity pyroelectrically, but it hinders rapid temperature variations. Therefore, the PZT sheet was fabricated to produce deeper trenches to cause lateral temperature gradients induced by the trenched electrode, enhancing the temperature variation rate under homogeneous heat irradiation. When the trenched electrode type with an electrode width of 200 μm and a cutting depth of 150 μm was used to fabricate a PZT pyroelectric cell with a 200 μm thick PZT sheet, the temperature variation rate was improved by about 55%. Therefore, the trenched electrode design did indeed enhance the temperature variation rate and the efficiency of pyroelectric energy converters.

  11. Theoretical Study of Midwave Infrared HgCdTe nBn Detectors Operating at Elevated Temperatures

    Science.gov (United States)

    Akhavan, Nima Dehdashti; Jolley, Gregory; Umana-Membreno, Gilberto A.; Antoszewski, Jarek; Faraone, Lorenzo

    2015-09-01

    We report a theoretical study of mercury cadmium telluride (HgCdTe) unipolar n-type/barrier/ n-type (nBn) detectors for midwave infrared (MWIR) applications at elevated temperatures. The results obtained indicate that the composition, doping, and thickness of the barrier layer in MWIR HgCdTe nBn detectors can be optimized to yield performance levels comparable with those of ideal HgCdTe p- n photodiodes. It is also shown that introduction of an additional barrier at the back contact layer of the detector structure (nBnn+) leads to substantial suppression of the Auger generation-recombination (GR) mechanism; this results in an order-of-magnitude reduction in the dark current level compared with conventional nBn or p- n junction-based detectors, thus enabling background-limited detector operation above 200 K.

  12. Study of polymorphous silicon as thermo-sensing film for infrared detectors

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, M., E-mail: mariomoreno78@hotmail.com [Instituto Nacional de Astrofisica, Optica y Electronica, INAOE, Puebla (Mexico); Torres, A. [Instituto Nacional de Astrofisica, Optica y Electronica, INAOE, Puebla (Mexico); Ambrosio, R. [Universidad Autonoma de Ciudad Juarez, Chihuahua (Mexico); Torres, E. [Universidad Popular Autonoma del estado de Puebla, Puebla (Mexico); Rosales, P.; Zuniga, C.; Reyes-Betanzo, C.; Calleja, W.; De la Hidalga, J. [Instituto Nacional de Astrofisica, Optica y Electronica, INAOE, Puebla (Mexico); Monfil, K. [Universidad Autonoma de Ciudad Juarez, Chihuahua (Mexico)

    2012-06-05

    In this work we have deposited and characterized pm-Si:H thin films obtained by plasma deposition. Our aim is to use pm-Si:H as thermo-sensing element for infrared (IR) detectors based on un-cooled microbolometers. We have studied the electrical characteristics of pm-Si:H that are figures of merit important for IR detection, as activation energy, thermal coefficient of resistance (TCR), room temperature conductivity ({sigma}{sub RT}) and responsivity under IR radiation. The influence of the substrate temperature (200 Degree-Sign C and 300 Degree-Sign C) on the pm-Si:H characteristics has been also studied. Our results shown that pm-Si:H is an excellent candidate to be used as thermo-sensing film for microbolometers, due to its large activation energy and TCR, with an improved {sigma}{sub RT}.

  13. Symmetric Absorber-Coupled Far-Infrared Microwave Kinetic Inductance Detector

    Science.gov (United States)

    U-yen, Kongpop (Inventor); Wollack, Edward J. (Inventor); Brown, Ari D. (Inventor); Stevenson, Thomas R. (Inventor); Patel, Amil A. (Inventor)

    2016-01-01

    The present invention relates to a symmetric absorber-coupled far-infrared microwave kinetic inductance detector including: a membrane having an absorber disposed thereon in a symmetric cross bar pattern; and a microstrip including a plurality of conductor microstrip lines disposed along all edges of the membrane, and separated from a ground plane by the membrane. The conducting microstrip lines are made from niobium, and the pattern is made from a superconducting material with a transition temperature below niobium, including one of aluminum, titanium nitride, or molybdenum nitride. The pattern is disposed on both a top and a bottom of the membrane, and creates a parallel-plate coupled transmission line on the membrane that acts as a half-wavelength resonator at readout frequencies. The parallel-plate coupled transmission line and the conductor microstrip lines form a stepped impedance resonator. The pattern provides identical power absorption for both horizontal and vertical polarization signals.

  14. HgCdTe Avalanche Photodiode Detectors for Airborne and Spaceborne Lidar at Infrared Wavelengths

    Science.gov (United States)

    Sun, Xiaoli; Abshire, James B.; Beck, Jeffrey D.; Mitra, Pradip; Reiff, Kirk; Yang, Guangning

    2017-01-01

    We report results from characterizing the HgCdTe avalanche photodiode (APD) sensorchip assemblies (SCA) developed for lidar at infrared wavelength using the high density vertically integrated photodiodes (HDVIP) technique. These devices demonstrated high quantum efficiency, typically greater than 90 between 0.8 micrometers and the cut-off wavelength, greater than 600 APD gain, near unity excess noise factor, 6-10 MHz electrical bandwidth and less than 0.5 fW/Hz(exp.1/2) noise equivalent power (NEP). The detectors provide linear analog output with a dynamic range of 2-3 orders of magnitude at a fixed APD gain without averaging, and over 5 orders of magnitude by adjusting the APD and preamplifier gain settings. They have been successfully used in airborne CO2 and CH4 integrated path differential absorption (IPDA) lidar as a precursor for space lidar applications.

  15. Mid/far-infrared photo-detectors based on graphene asymmetric quantum wells

    Science.gov (United States)

    Ben Salem, E.; Chaabani, R.; Jaziri, S.

    2016-09-01

    We conducted a theoretical study on the electronic properties of a single-layer graphene asymmetric quantum well. Quantification of energy levels is limited by electron-hole conversion at the barrier interfaces and free-electron continuum. Electron-hole conversion at the barrier interfaces can be controlled by introducing an asymmetry between barriers and taking into account the effect of the interactions of the graphene sheet with the substrate. The interaction with the substrate induces an effective mass to carriers, allowing observation of Fabry-Pérot resonances under normal incidence and extinction of Klein tunneling. The asymmetry, between barriers creates a transmission gap between confined states and free-electron continuum, allowing the large graphene asymmetric quantum well to be exploited as a photo-detector operating at mid- and far-infrared frequency regimes.

  16. CdS/PbSe heterojunction for high temperature mid-infrared photovoltaic detector applications

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Binbin, E-mail: binbinweng@ou.edu, E-mail: shi@ou.edu; Qiu, Jijun; Zhao, Lihua; Chang, Caleb [The School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Shi, Zhisheng, E-mail: binbinweng@ou.edu, E-mail: shi@ou.edu [The School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Nanolight, Inc., Norman, Oklahoma 73069 (United States)

    2014-03-24

    n-CdS/p-PbSe heterojunction is investigated. A thin CdS film is deposited by chemical bath deposition on top of epitaxial PbSe film by molecular beam epitaxy on Silicon. Current-voltage measurements demonstrate very good junction characteristics with rectifying ratio of ∼178 and ideality factor of 1.79 at 300 K. Detectors made with such structure exhibit mid-infrared spectral photoresponse at room temperature. The peak responsivity R{sub λ} and specific detectivity D{sup *} are 0.055 A/W and 5.482 × 10{sup 8} cm·Hz{sup 1/2}/W at λ = 4.7 μm under zero-bias photovoltaic mode. Temperature-dependent photoresponse measurements show abnormal intensity variation below ∼200 K. Possible reasons for this phenomenon are also discussed.

  17. Detecting an infrared photon within an hour. Transition-edge detector at ALPS-II

    Energy Technology Data Exchange (ETDEWEB)

    Dreyling-Eschweiler, Jan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; Horns, Dieter [Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; Collaboration: ALPS-II collaboration

    2013-09-15

    An essential design requirement of the ALPS-II experiment is the efficient detection of single photons with a very low instrumental background of 10 {mu}Hz. In 2011 the ALPS collaboration started to set up a TES detector (Transition-Edge Sensor) for ALPS-II, the second phase of the experiment. Since mid of 2013 the setup is ready for characterization in the ALPS laboratory: an ADR cryostat (Adiabatic Demagnetization Refrigerator) as millikelvin environment, a low noise SQUID (Superconducting Quantum Interference Device) with electronics for read-out and a fiber-coupled high-efficient TES for near-infrared photons as sensor. First measurements have shown a good discrimination between noise and 1064 nm signals.

  18. HREM study on stacking structure of SiGe/Si infrared detector

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Stacking structure and defects in SiGe/P-Si infrared detector were studied by using localization high resolutionelectron microscopy (HREM). The photosensitive region in the detector consists of 3 P+-Si0.65 Ge0.35 layers and 2 UD-Si(undoped Si) layers. The interface between Si0.65 Ge0.35 and UD-Si is not sharp and has a transition zone with non-uniform contrast. The misfit stress of interface is distributed gradiently along the normal direction of the interface. Thereforethe crystal defects and serious lattice deformations on the interface have not been found. A defect area with a shape of in-verted triangle exists in the edge of photosensitive region. The main types of the defects in the area are stacking faults andmicrotwins. The stacking faults are on ( 1 11), and the thickness of the most microtwins is less than 4 interplanar spacingand the twin plane is (111). The Si0.65Ge0.35 and UD-Si layers on amorphous SiO2 layer consist of polycrystals grown byrandom nueleation, and are in wave

  19. Study of a Vuilleumier cycle cryogenic refrigerator for detector cooling on the limb scanning infrared radiometer

    Science.gov (United States)

    Russo, S. C.

    1976-01-01

    A program to detect and monitor the presence of trace constituents in the earth's atmosphere by using the Limb Scanning Infrared Radiometer (LSIR) is reported. The LSIR, which makes radiometric measurements of the earth's limb radiance profile from a space platform, contains a detector assembly that must be cooled to a temperature of 65 + or - 2 K. The feasibility of cooling the NASA-type detector package with Vuilleumier (VM) cryogenic refrigerator was investigated to develop a preliminary conceptual design of a VM refrigerator that is compatible with a flight-type LSIR instrument. The scope of the LSIR program consists of analytical and design work to establish the size, weight, power consumption, interface requirements, and other important characteristics of a cryogenic cooler that would meet the requirements of the LSIR. The cryogenic cooling requirements under the conditions that NASA specified were defined. Following this, a parametric performance analysis was performed to define the interrelationships between refrigeration characteristics and mission requirements. This effort led to the selection of an optimum refrigerator design for the LSIR mission.

  20. 热释电红外传感器在生物特征识别领域中的研究进展%Pyroelectric infrared(PIR) sensor in the field of biometric identification applications

    Institute of Scientific and Technical Information of China (English)

    冯莉; 明东; 徐瑞; 邱爽; 许敏鹏; 綦宏志; 万柏坤; 王威杰

    2011-01-01

    Biometrics makes use of the physiological or behavioral characteristics of people to validate their identities. Gait recognition is an emerging field of biometrics technologies, whose aim is to identify the individuals based on their walking style. Therefore, this technique has a bright prospect and gains more and more attention from the field of biomedical information detection. When a human walks, the motion of various components of the body produce a characteristic signature, and can be detected by PIR sensor. The features of human motion can be extracted by analyzing the output signals of PIR sensor, then the recognition of different persons or different motion styles can be realized. In this paper, the improvements of this topic in the last several years are discussed in detail from three parts: the sensor detection principle, the applications in the field of gait recognition, and the feature extraction and classification methods of the pyroelectric information. At the end of the survey, some vital problems of this research are presented and analyzed.%步态识别作为生物特征识别技术的一个新兴子领域,旨在根据人的行走姿势实现对个体身份的识别.人行走过程中身体各部分的红外热辐射信号具有某种个体特征,该特征信息能够被热释电红外传感器有效检测.通过分析传感器的输出信号,就可以提取出人体运动的特征性数据,实现对不同人、不同运动状态的识别.本文对热释电红外传感器应用于生物特征识别领域的研究进展进行论述,从传感器的探测原理、在步态识别中的应用以及热释电信息的特征提取与分类算法进行总结,并对当前该研究方向上亟待解决的问题作简要的分析.

  1. A long-range, wide field-of-view infrared eyeblink detector.

    Science.gov (United States)

    Ryan, Steven B; Detweiler, Krystal L; Holland, Kyle H; Hord, Michael A; Bracha, Vlastislav

    2006-04-15

    Classical conditioning of the eyeblink response in the rabbit is one of the most advanced models of learning and memory in the mammalian brain. Successful use of the eyeblink conditioning paradigm requires precise measurements of the eyeblink response. One common technique of eyelid movement detection utilizes measurements of infrared (IR) light reflected from the surface of the eye. The performance of current IR sensors, however, is limited by their sensitivity to ambient infrared noise, by their small field-of-view and by short working distances. To address these limitations, we developed an IR eyeblink detector consisting of a pulsing (62.5 kHz) IR light emitting diode (LED) paired with a silicon IR photodiode and circuit that synchronously demodulates the recorded signal and rejects background IR noise. The working distance of the sensor exceeds 20 mm, and the field-of-view is larger than the area of a rabbit's eye. Due to its superior characteristics, the new sensor is ideally suited for both standard eyeblink conditioning and for studies that utilize IR-containing visual stimuli and/or that are conducted in an environment contaminated with IR noise.

  2. Visible and Infrared Wavefront Sensing detectors review in Europe - part I

    Science.gov (United States)

    Feautrier, Philippe; Gach, Jean-luc

    2013-12-01

    The purpose of this review is to give an overview of the state of the art wavefront sensor detectors developments held in Europe for the last decade. A major breakthrough has been achieved with the development by e2v technologies of the CCD220 between 2004 and 2012. Another major breakthrough is currently achieved with the very successful development of fast low noise infrared arrays called RAPID. The astonishing results of this device will be showed for the first time in an international conference at AO4ELT3.The CCD220, a 240x240 pixels 8 outputs EMCCD (CCD with internal multiplication), offers less than 0.2 e readout noise at a frame rate of 1500 Hz with negligible dark current. The OCAM2 camera is the commercial product that drives this advanced device. This system, commercialized by First Light Imaging, is quickly described in this paper. An upgrade of OCAM2 is currently developed to boost its frame rate to 2 kHz, opening the window of XAO wavefront sensing for the ELT using 4 synchronized cameras and pyramid wavefront sensing. This upgrade and the results obtained are described extensively elsewhere in this conference (Gach et al).Since this major success, new detector developments started in Europe. The NGSD CMOS device is fully dedicated to Natural and Laser Guide Star AO for the E-ELT with ESO involvement. The spot elongation from a LGS Shack Hartman wavefront sensor necessitates an increase of the pixel format. The NGSD will be a 880x840 pixels CMOS detector with a readout noise of 3 e (goal 1e) at 700 Hz frame rate. New technologies will be developed for that purpose: advanced CMOS pixel architecture, CMOS back thinned and back illuminated device for very high QE, full digital outputs with signal digital conversion on chip. This innovative device will be used on the European ELT but also interests potentially all giant telescopes.Additional developments also started in 2009 for wavefront sensing in the infrared based on a new technological breakthrough

  3. Radiatively heated high voltage pyroelectric crystal pulser

    Energy Technology Data Exchange (ETDEWEB)

    Antolak, A.J., E-mail: antolak@sandia.gov [Sandia National Laboratories, Livermore, CA 94550 (United States); Chen, A.X. [Sandia National Laboratories, Livermore, CA 94550 (United States); Leung, K.-N. [Sandia National Laboratories, Livermore, CA 94550 (United States); Nuclear Engineering Department, University of California, Berkeley (United States); Morse, D.H.; Raber, T.N. [Sandia National Laboratories, Livermore, CA 94550 (United States)

    2014-01-21

    Thin lithium tantalate pyroelectric crystals in a multi-stage pulser were heated by quartz lamps during their charging phase to generate high voltage pulses. The charging voltage was determined empirically based on the measured breakdown voltage in air and verified by the induced breakdown voltage of an external high voltage power supply. A four-stage pyroelectric crystal device generated pulse discharges of up to 86 kV using both quartz lamps (radiative) and thermoelectric (conductive) heating. Approximately 50 mJ of electrical energy was harvested from the crystals when radiatively heated in air, and up to 720 mJ was produced when the crystals were submerged in a dielectric fluid. It is anticipated that joule-level pulse discharges could be obtained by employing additional stages and optimizing the heating configuration.

  4. Near-Infrared Image Reconstruction of Newborns' Brains: Robustness to Perturbations of the Source/Detector Location.

    Science.gov (United States)

    Ahnen, L; Wolf, M; Hagmann, C; Sanchez, S

    2016-01-01

    The brain of preterm infants is the most vulnerable organ and can be severely injured by cerebral ischemia. We are working on a near-infrared imager to early detect cerebral ischemia. During imaging of the brain, movements of the newborn infants are inevitable and the near-infrared sensor has to be able to function on irregular geometries. Our aim is to determine the robustness of the near-infrared image reconstruction to small variations of the source and detector locations. In analytical and numerical simulations, the error estimations for a homogeneous medium agree well. The worst case estimates of errors in reduced scattering and absorption coefficient for distances of r=40 mm are acceptable for a single source-detector pair. The optical properties of an inhomogeneity representing an ischemia are reconstructed correctly within a homogeneous medium, if the error in placement is random.

  5. Highly stretchable piezoelectric-pyroelectric hybrid nanogenerator.

    Science.gov (United States)

    Lee, Ju-Hyuck; Lee, Keun Young; Gupta, Manoj Kumar; Kim, Tae Yun; Lee, Dae-Yeong; Oh, Junho; Ryu, Changkook; Yoo, Won Jong; Kang, Chong-Yun; Yoon, Seok-Jin; Yoo, Ji-Beom; Kim, Sang-Woo

    2014-02-01

    A highly stretchable hybrid nanogenerator has been developed using a micro-patterned piezoelectric polymer P(VDF-TrFE), PDMS-CNT composite, and graphene nanosheets. Mechanical and thermal energies are simultaneously harvested from a single cell of the device. The hybrid nanogenerator exhibits high robustness behavior even after 30% stretching and generates very stable piezoelectric and pyroelectric power outputs due to micro-pattern designing. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Self Assembly and Pyroelectric Poling for Organics

    Science.gov (United States)

    2015-07-06

    ozone or nitrogen oxides) and energetic species from corona discharge . These problems can strongly inhibit the efficient poling and large-scale...respectively. In this idealized model , a modest temperature change (10 to 50 °C) will lead to a considerably large electrostatic field in a thin film dielectric...measurement); (e) contact poling. 4. Systematically analyze electrostatics models to quantify electric field generation from commonly used pyroelectric

  7. Design, fabrication and testing of 17um pitch 640x480 uncooled infrared focal plane array detector

    Science.gov (United States)

    Jiang, Lijun; Liu, Haitao; Chi, Jiguang; Qian, Liangshan; Pan, Feng; Liu, Xiang

    2015-10-01

    Uncooled infrared focal plane array (UIRFPA) detectors are widely used in industrial thermography cameras, night vision goggles, thermal weapon sights, as well as automotive night vision systems. To meet the market requirement for smaller pixel pitch and higher resolution, we have developed a 17um pitch 640x480 UIRFPA detector. The detector is based on amorphous silicon (a-Si) microbolometer technology, the readout integrated circuit (ROIC) is designed and manufactured with 0.35um standard CMOS technology on 8 inch wafer, the microbolometer is fabricated monolithically on the ROIC using an unique surface micromachining process developed inside the company, the fabricated detector is vacuum packaged with hermetic metal package and tested. In this paper we present the design, fabrication and testing of the 17um 640x480 detector. The design trade-off of the detector ROIC and pixel micro-bridge structure will be discussed, by comparison the calculation and simulation to the testing results. The novel surface micromachining process using silicon sacrificial layer will be presented, which is more compatible with the CMOS process than the traditional process with polyimide sacrificial layer, and resulted in good processing stability and high fabrication yield. The performance of the detector is tested, with temperature equivalent temperature difference (NETD) less than 60mK at F/1 aperture, operability better than 99.5%. The results demonstrate that the detector can meet the requirements of most thermography and night vision applications.

  8. Design of non-dispersion Infrared detector's data processor on measurement of automobile emission CO and CO2

    Science.gov (United States)

    Liu, Guohua; Zhang, Yujun; Chen, Chen; Lu, Yibing; He, Chungui; Gao, Yanwei; You, Kun; He, Ying; Zhang, Kai; Liu, Wenqing

    2016-10-01

    For the technical requirements of automobile emission CO and CO2 detector's data processor, the scheme is based on the detection principle of NDIR method and the implementation of the data processor software as well as hardware is discussed. High-speed, high-precision DSP is selected as the core of the detector's data acquisition and processing, while four-channel thermoelectricity sensor TPS4339 as infrared detector, digital-analog data acquisition circuit of NDIR is designed and simulated. Then Fast Fourier Transform (FFT) is adopted for signal processing. Automobile emission CO and CO2 concentration can be accurately obtained by appropriately adjusting sampling period and the light source modulation frequencies, the system SNR is improved and the detection limit is reduced. The experimental results show that the detector's data processor has 3% accuracy and stability which can meet the measurement and analysis of automobile emission CO and CO2 concentration.

  9. Infrared

    Science.gov (United States)

    Vollmer, M.

    2013-11-01

    'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the

  10. InAs/GaSb type-II superlattice infrared detectors: Future prospect

    Science.gov (United States)

    Rogalski, A.; Martyniuk, P.; Kopytko, M.

    2017-09-01

    Investigations of antimonide-based materials began at about the same time as HgCdTe ternary alloys—in the 1950s, and the apparent rapid success of their technology, especially low-dimensional solids, depends on the previous five decades of III-V materials and device research. However, the sophisticated physics associated with the antimonide-based bandgap engineering concept started at the beginning of 1990s gave a new impact and interest in development of infrared detector structures within academic and national laboratories. The development of InAs/GaSb type-II superlattices (T2SLs) results from two primary motivations: the perceived challenges of reproducibly fabricating high-operability HgCdTe focal plane arrays (FPAs) at reasonable cost and the theoretical predictions of lower Auger recombination for type T2SL detectors compared with HgCdTe. Second motivation—lower Auger recombination should be translated into a fundamental advantage for T2SL over HgCdTe in terms of lower dark current and/or higher operating temperature, provided other parameters such as Shockley-Read-Hall (SRH) lifetime are equal. InAs/GaSb T2SL photodetectors offer similar performance to HgCdTe at an equivalent cut-off wavelength, but with a sizeable penalty in operating temperature, due to the inherent difference in SRH lifetimes. It is predicted that since the future infrared (IR) systems will be based on the room temperature operation of depletion-current limited arrays with pixel densities that are fully consistent with background- and diffraction-limited performance due to the system optics, the material system with long SRH lifetime will be required. Since T2SLs are very much resisted in attempts to improve its SRH lifetime, currently the only material that meets this requirement is HgCdTe. Due to less ionic chemical bonding, III-V semiconductors are more robust than their II-VI counterparts. As a result, III-V-based FPAs excel in operability, spatial uniformity, temporal stability

  11. The Electronic Structure and Secondary Pyroelectric Properties of Lithium Tetraborate

    Directory of Open Access Journals (Sweden)

    Peter A. Dowben

    2010-09-01

    Full Text Available We review the pyroelectric properties and electronic structure of Li2B4O7(110 and Li2B4O7(100 surfaces. There is evidence for a pyroelectric current along the [110] direction of stoichiometric Li2B4O7 so that the pyroelectric coefficient is nonzero but roughly 103 smaller than along the [001] direction of spontaneous polarization. Abrupt decreases in the pyroelectric coefficient along the [110] direction can be correlated with anomalies in the elastic stiffness  contributing to the concept that the pyroelectric coefficient is not simply a vector but has qualities of a tensor, as expected. The time dependent surface photovoltaic charging suggests that surface charging is dependent on crystal orientation and doping, as well as temperature.

  12. The off-axis pyroelectric effect observed for lithium tetraborate

    Energy Technology Data Exchange (ETDEWEB)

    Ketsman, I. [Dept. of Physics and Astronomy and the Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, PO Box 880111, Lincoln, NE 68588-0111 (United States); Wooten, D. [Air Force Institute of Technology, 2950 Hobson Way, Wright Patterson Air Force Base, OH 45433-7765 (United States); Xiao, Jie [Dept. of Physics and Astronomy and the Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, PO Box 880111, Lincoln, NE 68588-0111 (United States); Losovyj, Ya.B. [Dept. of Physics and Astronomy and the Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, PO Box 880111, Lincoln, NE 68588-0111 (United States); J. Bennett Johnston Sr. Center for Advanced Microstructures and Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, LA 70806 (United States); Burak, Ya.V.; Adamiv, V.T. [Institute of Physical Optics, 23 Dragomanov Street, Lviv 79005 (Ukraine); Sokolov, A. [Dept. of Physics and Astronomy and the Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, PO Box 880111, Lincoln, NE 68588-0111 (United States); Petrosky, J.; McClory, J. [Air Force Institute of Technology, 2950 Hobson Way, Wright Patterson Air Force Base, OH 45433-7765 (United States); Dowben, P.A., E-mail: pdowben@unl.ed [Dept. of Physics and Astronomy and the Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, PO Box 880111, Lincoln, NE 68588-0111 (United States)

    2010-01-25

    We find a pyroelectric current along the <110> direction of stoichiometric Li{sub 2}B{sub 4}O{sub 7} so that the pyroelectric coefficient is nonzero but roughly 10{sup -3} smaller than along the <001> direction of spontaneous polarization. Abrupt decreases in the pyroelectric coefficient along the <110> direction can be correlated with anomalies in the elastic stiffness C{sub 33}{sup D} contributing to concept that the pyroelectric coefficient is not simply a vector but has qualities of a tensor, as expected. The time dependent surface photovoltaic charging suggests that an inverse piezoelectric effect occurs at the (110) surface but not the (100) surface. Both effects along the <110> direction or at the (110) surface are distinct the conventional as a bulk pyroelectric effect.

  13. Thermally induced atmospheric pressure gas discharges using pyroelectric crystals

    Science.gov (United States)

    Johnson, Michael J.; Linczer, John; Go, David B.

    2014-12-01

    Using a heated pyroelectric crystal, an atmospheric pressure gas discharge was generated through the input of heat. When put through a change in temperature, the polarization of a pyroelectric can change significantly, creating a substantial electric potential at its surface. When configured with a grounded sharp counter electrode, a large inhomogeneous electric field forms in the interstitial gas to initiate a corona-like discharge. Under constant heating conditions, gaseous ions drifting to the pyroelectric accumulate and screen the electric field, extinguishing the discharge. By thermally cycling the pyroelectric, negative and positive discharges are generated during heating and cooling, respectively, with peak currents on the order of 80 nA. Time-integrated visualization confirmed the generation of both a corona-like discharge and a surface discharge on the pyroelectric. Parametric studies identified that thermal cycling conditions significantly influence discharge formation for this new atmospheric pressure discharge approach.

  14. Study of pyroelectric activity of PZT/PVDF-HFP composite

    Directory of Open Access Journals (Sweden)

    Luiz Francisco Malmonge

    2003-12-01

    Full Text Available Flexible, free-standing piezo and pyroelectric composite with 0 to 3 connectivity was made up from Lead Zirconate Titanate (PZT powder and poly(vinylidene fluoride-hexafluoropropylene (PVDF-HFP copolymer. The pyroelectric and the piezoelectric longitudinal (d33 coefficients were measured. A 50/50 vol.% PZT/PVDF-HFP composite resulted in piezo and pyroelectric coefficients of d33 = 25.0 pC/N and p = 4.5 × 10-4 C/m²K at 70 °C, respectively. Analysis of the complex permittivity in a wide range of frequency was carried out indicating lower permittivity of the composite in comparison with a permittivity of the PZT ceramic. The low value of the permittivity gives a high pyroelectric figure of merit indicating that this material can be used to build a temperature sensor in spite of the lower pyroelectric coefficient compared with PZT.

  15. Simulation and analysis of grating-integrated quantum dot infrared detectors for spectral response control and performance enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Oh Kim, Jun [Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106 (United States); Division of Industrial Metrology, Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of); Ku, Zahyun; Urbas, Augustine, E-mail: youngchul.jun@inha.ac.kr, E-mail: Augustine.Urbas@wpafb.af.mil [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); Krishna, Sanjay [Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106 (United States); Kang, Sang-Woo; Jun Lee, Sang [Division of Industrial Metrology, Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of); Chul Jun, Young, E-mail: youngchul.jun@inha.ac.kr, E-mail: Augustine.Urbas@wpafb.af.mil [Department of Physics, Inha University, Incheon 402-751 (Korea, Republic of)

    2014-04-28

    We propose and analyze a novel detector structure for pixel-level multispectral infrared imaging. More specifically, we investigate the device performance of a grating-integrated quantum dots-in-a-well photodetector under backside illumination. Our design uses 1-dimensional grating patterns fabricated directly on a semiconductor contact layer and, thus, adds a minimal amount of additional effort to conventional detector fabrication flows. We show that we can gain wide-range control of spectral response as well as large overall detection enhancement by adjusting grating parameters. For small grating periods, the spectral responsivity gradually changes with parameters. We explain this spectral tuning using the Fabry–Perot resonance and effective medium theory. For larger grating periods, the responsivity spectra get complicated due to increased diffraction into the active region, but we find that we can obtain large enhancement of the overall detector performance. In our design, the spectral tuning range can be larger than 1 μm, and, compared to the unpatterned detector, the detection enhancement can be greater than 92% and 148% for parallel and perpendicular polarizations. Our work can pave the way for practical, easy-to-fabricate detectors, which are highly useful for many infrared imaging applications.

  16. Development of a miniature coaxial pulse tube cryocooler for a space-borne infrared detector system

    Science.gov (United States)

    Dang, H. Z.; Wang, L. B.; Wu, Y. N.; Yang, K. X.; Shen, W. B.

    2010-04-01

    A single-stage miniature coaxial pulse tube cryocooler prototype is developed to provide reliable low-noise cooling for an infrared detector system to be equipped in the future space mission. The challenging work is the exacting requirement on its dimensions due to the given miniature Dewar. The limited dimensions result in the insufficiency of the phaseshifting ability of the system when inertance tubes alone are employed. A larger filling pressure of 3.5 Mpa and higher operating frequency up to 70 Hz are adopted to increase the energy density, which compensates for the decrease in working gas volume due to the miniature structure, and realize a fast cool down process. A 1.5 kg dual opposed linear compressor based on flexure bearing and moving magnet technology is used to realize light weight, high efficiency and low contamination. The design and optimization are based on the theoretical CFD model developed by the analyses of thermodynamic behaviors of gas parcels in the oscillating flow. This paper describes the design approach and trade-offs. The cooler performance and characteristics are presented.

  17. Pyroelectric electron emissions and domain inversion of LiNbO{sub 3} single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Wook [Samsung Advanced Institute of Technology, U-Team, P.O. Box 111, Suwon, Kyongki 440-600 (Korea, Republic of)]. E-mail: Peterkim@ucsd.edu; Bourim, E.M. [Samsung Advanced Institute of Technology, U-Team, P.O. Box 111, Suwon, Kyongki 440-600 (Korea, Republic of); Jeong, Soo-Hwan [Samsung Advanced Institute of Technology, U-Team, P.O. Box 111, Suwon, Kyongki 440-600 (Korea, Republic of); Yoo, In K. [Samsung Advanced Institute of Technology, U-Team, P.O. Box 111, Suwon, Kyongki 440-600, Korea (Korea)

    2004-10-30

    We investigated the electron emissions from a congruent LiNbO{sub 3} single crystal with variation in temperature. When there was a small gap between the crystal and detector (<2 mm), we observed abrupt drops in the emission current and polarization domain inversion of the crystal. The current burst was distributed in tree-like patterns that suggested plasma generation. A sufficient gap and a crystal with a high coercive field appear to be factors that allow reproducible electron emissions from pyroelectric materials.

  18. Detector control and data acquisition for the wide field infrared survey telescope (WFIRST) with a custom ASIC

    Science.gov (United States)

    Smith, Brian; Loose, Markus; Alkire, Greg; Joshi, Atul; Kelly, Daniel; Siskind, Eric; Rossetti, Dino; Mah, Jonathan; Cheng, Edward; Miko, Laddawan; Luppino, Gerard; Culver, Harry; Wollack, Edward; Content, David

    2016-07-01

    The Wide-Field Infrared Survey Telescope (WFIRST) will have the largest near-IR focal plane ever flown by NASA, a total of 18 4K x 4K devices. The project has adopted a system-level approach to detector control and data acquisition where 1) control and processing intelligence is pushed into components closer to the detector to maximize signal integrity, 2) functions are performed at the highest allowable temperatures, and 3) the electronics are designed to ensure that the intrinsic detector noise is the limiting factor for system performance. For WFIRST, the detector arrays operate at 90 to 100 K, the detector control and data acquisition functions are performed by a custom ASIC at 150 to 180 K, and the main data processing electronics are at the ambient temperature of the spacecraft, notionally 300 K. The new ASIC is the main interface between the cryogenic detectors and the warm instrument electronics. Its single-chip design provides basic clocking for most types of hybrid detectors with CMOS ROICs. It includes a flexible but simple-to-program sequencer, with the option of microprocessor control for more elaborate readout schemes that may be data-dependent. All analog biases, digital clocks, and analog-to-digital conversion functions are incorporated and are connected to the nearby detectors with a short cable that can provide thermal isolation. The interface to the warm electronics is simple and robust through multiple LVDS channels. It also includes features that support parallel operation of multiple ASICs to control detectors that may have more capability or requirements than can be supported by a single chip.

  19. Elemental boron-doped p(+)-SiGe layers grown by molecular beam epitaxy for infrared detector applications

    Science.gov (United States)

    Lin, T. L.; George, T.; Jones, E. W.; Ksendzov, A.; Huberman, M. L.

    1992-01-01

    SiGe/Si heterojunction internal photoemission (HIP) detectors have been fabricated utilizing molecular beam epitaxy of p(+)-SiGe layers on p(-)-Si substrates. Elemental boron from a high-temperature effusion cell was used as the dopant source during MBE growth, and high doping concentrations have been achieved. Strong infrared absorption, mainly by free-carrier absorption, was observed for the degenerately doped SiGe layers. The use of elemental boron as the dopant source allows a low MBE growth temperature, resulting in improved crystalline quality and smooth surface morphology of the Si(0.7)Ge(0.3) layers. Nearly ideal thermionic emission dark current characteristics have been obtained. Photoresponse of the HIP detectors in the long-wavelength infrared regime has been demonstrated.

  20. GaAs Based InAs/GaSb Superlattice Short Wavelength Infrared Detectors Grown by Molecular Beam Epitaxy

    Institute of Scientific and Technical Information of China (English)

    TANG Bao; XU Ying-Qiang; ZHOU Zhi-Qiang; HAO Rui-Ting; WANG Guo-Wei; REN Zheng-Wei; NIU Zhi-Chuan

    2009-01-01

    InAs/GaSb superlattice (SL) short wavelength infrared photoconduction detectors are grown by molecular beam epitaxy on GaAs(O01) semi-insulating substrates. An interracial misfit mode A1Sb quantum dot layer and a thick GaSb layer are grown as buffer layers. The detectors containing a 200-period 2 ML/8 ML InAs/GaSb SL active layer are fabricated with a pixel area of 800×800 μm2 without using passivation or antireflection coatings. Corresponding to the 50% cutoff wavelengths of 2.05 μm at 77K and 2.25 μ m at 300 K, the peak detectivities of the detectors are 4 × 109 cm·Hz1/2/W at 77K and 2 × 108 cm.Hz1/2/W at 30OK, respectively.

  1. Status of HgCdTe Barrier Infrared Detectors Grown by MOCVD in Military University of Technology

    Science.gov (United States)

    Kopytko, M.; Jóźwikowski, K.; Martyniuk, P.; Gawron, W.; Madejczyk, P.; Kowalewski, A.; Markowska, O.; Rogalski, A.; Rutkowski, J.

    2016-09-01

    In this paper we present the status of HgCdTe barrier detectors with an emphasis on technological progress in metalorganic chemical vapor deposition (MOCVD) growth achieved recently at the Institute of Applied Physics, Military University of Technology. It is shown that MOCVD technology is an excellent tool for HgCdTe barrier architecture growth with a wide range of composition, donor /acceptor doping, and without post-grown annealing. The device concept of a specific barrier bandgap architecture integrated with Auger-suppression is as a good solution for high-operating temperature infrared detectors. Analyzed devices show a high performance comparable with the state-of-the-art of HgCdTe photodiodes. Dark current densities are close to the values given by "Rule 07" and detectivities of non-immersed detectors are close to the value marked for HgCdTe photodiodes. Experimental data of long-wavelength infrared detector structures were confirmed by numerical simulations obtained by a commercially available software APSYS platform. A detailed analysis applied to explain dark current plots was made, taking into account Shockley-Read-Hall, Auger, and tunneling currents.

  2. Secondary pyroelectric and electrocaloric effects in thin films

    Science.gov (United States)

    Tong, Trong

    The pyroelectric and electrocaloric effect play an important role in many applications such as energy harvesting and solid-state cooling. This dissertation focuses on the characterization of the pyroelectric and electric coefficient in thin film using novel laser-based technique. The implementation of the systems is described in detail, and heat transport models are developed to interpret the experimental data. The temperature oscillation caused by the modulated laser power or the entropy change are calculated over a wide range of the modulation frequency. These techniques are applied to characterize Pb(ZrTi)O3 and Ba(SrTi)O3 films growth by Pulse Laser Deposition (PLD) and sol-gel method. The secondary pyroelectric and electrocaloric contributions caused by clamping substrate effect are discussed. A wide range frequency analysis is applied to extract the secondary pyroelectric coefficient. The secondary pyroelectric effect is found to have the same dependence on applied field as the pyroelectric coefficient and is approximately 15% and 20% of the total response for PbZr 0.2Ti0.8O3 and Ba0.6Sr0.4TiO 3 grown by PLD, respectively. By comparing the pyroelectric and electrocaloric coefficient measured on the same devices, our result shows the secondary contribution to the electrocaloric coefficient has the opposite sign as the primary effect and therefore reduces the overall entropy change of Pb(ZrTi)O3 in an electric field. Finally, the sol-gel method is used to produce Pb(ZrTi)O 3 thin films. The sample fabrication is described in detail along with physical characterization and the pyroelectric measurement. Sol-gel PZT films are perovskite phase with (100) orientation. The pyroelectric coefficient is measured to be 135 microC m-2 K-1.

  3. Infrared microspectroscopic imaging using a large radius germanium internal reflection element and a focal plane array detector.

    Science.gov (United States)

    Patterson, Brian M; Havrilla, George J; Marcott, Curtis; Story, Gloria M

    2007-11-01

    Previously, we established the ability to collect infrared microspectroscopic images of large areas using a large radius hemisphere internal reflection element (IRE) with both a single point and a linear array detector. In this paper, preliminary work in applying this same method to a focal plane array (FPA) infrared imaging system is demonstrated. Mosaic tile imaging using a large radius germanium hemispherical IRE on a FPA Fourier transform infrared microscope imaging system can be used to image samples nearly 1.5 mm x 2 mm in size. A polymer film with a metal mask is imaged using this method for comparison to previous work. Images of hair and skin samples are presented, highlighting the complexity of this method. Comparisons are made between the linear array and FPA methods.

  4. Study of pyroelectric activity of PZT/PVDF-HFP composite

    OpenAIRE

    Luiz Francisco Malmonge; José Antonio Malmonge; Walter Katsumi Sakamoto

    2003-01-01

    Flexible, free-standing piezo and pyroelectric composite with 0 to 3 connectivity was made up from Lead Zirconate Titanate (PZT) powder and poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) copolymer. The pyroelectric and the piezoelectric longitudinal (d33) coefficients were measured. A 50/50 vol.% PZT/PVDF-HFP composite resulted in piezo and pyroelectric coefficients of d33 = 25.0 pC/N and p = 4.5 × 10-4 C/m²K at 70 °C, respectively. Analysis of the complex permittivity in a wide ran...

  5. Piezoelectric and pyroelectric effects of a crystalline polymer

    Science.gov (United States)

    Kundu, Nikhil K.; Kundu, Malay

    1990-01-01

    Polyvinylidene flouride (PVDF) is a crystalline polymer to both piezoelectric and pyroelectric nature. Piezoelectricity produces electrical signals when mechanically deformed, and pyroelectricity is the electrical polarization induced by thermal absorption in crystals. To demonstrate the piezoelectric effect PVDF is subjected to impact loads which produce electrical charges proportional to mechanical stresses. A heat source was used to demonstrate the pyroelectric nature of PVDF. The rise in temperature due to absorbed energy by the polymer produces electrical output. The qualitative test results obtained are graphically reproduced.

  6. A Novel Compact Pyroelectric X-Ray and Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Yaron Danon

    2007-08-31

    This research was focused on the utilization of pyroelectric crystals for generation of radiation. When in constant temperature pyroelectric crystals are spontaneously polarized. The polarization causes internal charges to accumulate near the crystal faces and masking charges from the environment are attracted to the crystal faces and neutralize the charge. When a pyroelectric crystal is heated or cooled it becomes depolarized and the surface charges become available. If the heating or cooling is done on a crystal in vacuum where no masking charges are available, the crystal becomes a charged capacitor and because of its small capacitance large potential develops across the faces of the crystal.

  7. Evaluation of Pyro-optic Materials for Infrared Imaging

    Science.gov (United States)

    Pandey, R. K.; Kotru, Sushma; Song, Xiuyu; Donnelly, David

    2004-03-01

    Infrared detectors are needed for a wide range of applications. IR detectors operate either on the principles of photon detection or pyroelectric detection. Both these systems have their respective advantages and disadvantages. However, both of them inherently have difficulties in management of noise to signal ratio and in read-out circuitory. One of the most serious handicaps of photon detectors is requirement of cryogenic cooling for satisfactory operation. In this respect uncooled pyroelectric detectors operating at above room temperature have an advantage. An alternative to these approaches can be pyro-optic based detectors. Only a handful of materials have been found with some satisfactory level of pyro-optic coefficients appropriate for imaginig devices. Some of them are: antimony-sulfo-iodide (SbSI), molybdenum sulfide (MoS2), bismuth vanadate (BiVO4) and Pb-based titanates. Pyrooptic coefficients of these materials have been reported using presumably bulk single crystals. However, no such data are available for their thin films which would be very important for light weight integrated structured devices.In this paper we will describe the parameters and optimization protocol for the growh of thin films of these materials on thermally insulating substrates. We will also discuss their structural, electrical and optical properties. Our investigations suggest that SbSI, BiVO4 and PNZT films are attractive options for advancing the IR detecting technology by utilizing the pyro-optic effect. Integrated thin film structures might lead to the fabrication of light weight, low cost, noise immune and efficient imaging devices based on pyro-optic properties. This research is sponsored by the DEPSCoR program of the U.S. Army Research Office.

  8. Therapeutic dose from a pyroelectric electron accelerator.

    Science.gov (United States)

    Fullem, T Z; Fazel, K C; Geuther, J A; Danon, Y

    2009-11-01

    Simple heating of pyroelectric crystals has been used as the basis for compact sources of X rays, electrons, ions and neutrons. We report on the evaluation of the feasibility of using a portable pyroelectric electron accelerator to deliver a therapeutic dose to tissue. Such a device could be mass produced as a handheld, battery-powered instrument. Experiments were conducted with several crystal sizes in which the crystal was heated inside a vacuum chamber and the emitted electrons were allowed to penetrate a thin beryllium window into the surrounding air. A Faraday cup was used to count the number of electrons that exited the window. The energy of these electrons was determined by measuring the energy spectrum of the X rays that resulted from the electron interactions with the Faraday cup. Based on these measurements, the dose that this source could deliver to tissue was calculated using Monte Carlo calculations. It was found that 10(13) electrons with a peak energy of the order of 100 keV were emitted from the beryllium window and could deliver a dose of 1664 Gy to a 2-cm-diameter, 110-microm-deep region of tissue located 1.5 cm from the window with air between the window and the tissue. This dose level is high enough to consider this technology for medical applications in which shallow energy deposition is beneficial.

  9. Infrared LED Enhanced Spectroscopic CdZnTe Detector Working under High Fluxes of X-rays

    Directory of Open Access Journals (Sweden)

    Jakub Pekárek

    2016-09-01

    Full Text Available This paper describes an application of infrared light-induced de-polarization applied on a polarized CdZnTe detector working under high radiation fluxes. We newly demonstrate the influence of a high flux of X-rays and simultaneous 1200-nm LED illumination on the spectroscopic properties of a CdZnTe detector. CdZnTe detectors operating under high radiation fluxes usually suffer from the polarization effect, which occurs due to a screening of the internal electric field by a positive space charge caused by photogenerated holes trapped at a deep level. Polarization results in the degradation of detector charge collection efficiency. We studied the spectroscopic behavior of CdZnTe under various X-ray fluxes ranging between 5 × 10 5 and 8 × 10 6 photons per mm 2 per second. It was observed that polarization occurs at an X-ray flux higher than 3 × 10 6 mm − 2 ·s − 1 . Using simultaneous illumination of the detector by a de-polarizing LED at 1200 nm, it was possible to recover X-ray spectra originally deformed by the polarization effect.

  10. Infrared LED Enhanced Spectroscopic CdZnTe Detector Working under High Fluxes of X-rays.

    Science.gov (United States)

    Pekárek, Jakub; Dědič, Václav; Franc, Jan; Belas, Eduard; Rejhon, Martin; Moravec, Pavel; Touš, Jan; Voltr, Josef

    2016-09-27

    This paper describes an application of infrared light-induced de-polarization applied on a polarized CdZnTe detector working under high radiation fluxes. We newly demonstrate the influence of a high flux of X-rays and simultaneous 1200-nm LED illumination on the spectroscopic properties of a CdZnTe detector. CdZnTe detectors operating under high radiation fluxes usually suffer from the polarization effect, which occurs due to a screening of the internal electric field by a positive space charge caused by photogenerated holes trapped at a deep level. Polarization results in the degradation of detector charge collection efficiency. We studied the spectroscopic behavior of CdZnTe under various X-ray fluxes ranging between 5 × 10 5 and 8 × 10 6 photons per mm 2 per second. It was observed that polarization occurs at an X-ray flux higher than 3 × 10 6 mm - 2 ·s - 1 . Using simultaneous illumination of the detector by a de-polarizing LED at 1200 nm, it was possible to recover X-ray spectra originally deformed by the polarization effect.

  11. Growth and characterization of crystals for room temperature I.R. detectors and second harmonic generation devices

    Science.gov (United States)

    Lal, R. B.

    1995-01-01

    One of the major objectives of this program was to modify the triglycine sulfate (TGS) crystals with suitable dopants and variants to achieve better pyroelectric properties and improved infrared detectivities (D(sup *)), and higher Curie transition temperature compared to undoped TGS crystals. Towards these objectives, many promising dopants, both inorganic and organic, were investigated in the last few years. These dopants gave significant improvement in the D(sup *) value of the infrared detectors fabricated from the grown crystals with no significant increase in the Curie temperature (49 C). The IR detectors were fabricated at EDO/Barnes Engineering Division, Shelton, CT. In the last one year many TGS crystals doped with urea were grown using the low temperature solution crystal growth facility. It is found that doping with urea, the normalized growth yield increased significantly compared to pure TGS crystals and there is an improvement in the pyroelectric and dielectric constant values of doped crystals. This gave a significant increase in the materials figure of merits. The Vicker's hardness of 10 wt percent urea doped crystals is found to be about three times higher in the (010) direction compared to undoped crystals. This report describes in detail the results of urea doped TGS crystals.

  12. Invited Review Article: Practical guide for pyroelectric measurementsa)

    Science.gov (United States)

    Lubomirsky, Igor; Stafsudd, Oscar

    2012-05-01

    The characterization of pyroelectric materials is a necessary stage in the design of a large variety of pyroelectric-based devices ranging from intrusion alarms to IR cameras. The sample configurations and measurement techniques currently in use vary widely and require careful attention in order to avoid artifacts. In this review, we provide a practical guide to the measurement of the pyroelectric coefficient, paying particular attention to the new instrumental possibilities (fast sinusoidally modulated light sources, low impedance broad band current meters, and fast averaging oscilloscopes) that have become available during the last decade. Techniques applicable to bulk specimens, substrate-supported films, and self-supported films are described in detail. The most commonly used procedures are classified according to the type of thermal excitation: continuous ramping, heat pulse, and continuous oscillation. In the appendices, we describe the practical realization of these measurement schemes and provide mathematical descriptions for the extraction of the pyroelectric coefficient from the measured data.

  13. Superconducting nanowire single-photon detectors (SNSPDs) on SOI for near-infrared range

    Energy Technology Data Exchange (ETDEWEB)

    Trojan, Philipp; Il' in, Konstantin; Henrich, Dagmar; Hofherr, Matthias; Doerner, Steffen; Siegel, Michael [Institut fuer Mikro- und Nanoelektronische Systeme (IMS), Karlsruher Institut fuer Technologie (KIT) (Germany); Semenov, Alexey [Institut fuer Planetenforschung, DLR, Berlin-Adlershof (Germany); Huebers, Heinz-Wilhelm [Institut fuer Planetenforschung, DLR, Berlin-Adlershof (Germany); Institut fuer Optik und Atomare Physik, Technische Universitaet Berlin (Germany)

    2013-07-01

    Superconducting nanowire single-photon detectors are promising devices for photon detectors with high count rates, low dark count rates and low dead times. At wavelengths beyond the visible range, the detection efficiency of today's SNSPDs drops significantly. Moreover, the low absorption in ultra-thin detector films is a limiting factor over the entire spectral range. Solving this problem requires approaches for an enhancement of the absorption range in feeding the light to the detector element. A possibility to obtain a better absorption is the use of multilayer substrate materials for photonic waveguide structures. We present results on development of superconducting nanowire single-photon detectors made from niobium nitride on silicon-on-insulator (SOI) multilayer substrates. Optical and superconducting properties of SNSPDs on SOI will be discussed and compared with the characteristics of detectors on common substrates.

  14. High-Bandwidth Photon-Counting Detectors with Enhanced Near-Infrared Response Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Long-range optical telecommunications (LROT) impose challenging requirements on detector array sensitivity at 1064nm and arrays timing bandwidth. Large photonic...

  15. Performance of the Imaging Fourier Transform Spectrometer with Photoconductive Detector Arrays: An Application for the AKARI Far-Infrared Instrument

    CERN Document Server

    Kawada, Mitsunobu; Murakami, Noriko; Matsuo, Hiroshi; Okada, Yoko; Yasuda, Akiko; Matsuura, Shuji; Shirahata, Mai; Doi, Yasuo; Kaneda, Hidehiro; Ootsubo, Takafumi; Nakagawa, Takao; Shibai, Hiroshi

    2008-01-01

    We have developed an imaging Fourier transform spectrometer (FTS) for space-based far-infrared astronomical observations. The FTS employs a newly developed photoconductive detector arrays with a capacitive trans-impedance amplifier, which makes the FTS a completely unique instrument. The FTS was installed as a function of the far-infrared instrument (FIS: Far-Infrared Surveyor) on the Japanese astronomical satellite, AKARI, which was launched on February 21, 2006 (UT) from the Uchinoura Space Center. The FIS-FTS had been operated for more than one year before liquid helium ran out on August 26, 2007. The FIS-FTS was operated nearly six hundreds times, which corresponds to more than one hundred hours of astronomical observations and almost the same amount of time for calibrations. As expected from laboratory measurements, the FIS-FTS performed well and has produced a large set of astronomical data for valuable objects. Meanwhile, it becomes clear that the detector transient effect is a considerable factor for ...

  16. Wavelength- or Polarization-Selective Thermal Infrared Detectors for Multi-Color or Polarimetric Imaging Using Plasmonics and Metamaterials.

    Science.gov (United States)

    Ogawa, Shinpei; Kimata, Masafumi

    2017-05-04

    Wavelength- or polarization-selective thermal infrared (IR) detectors are promising for various novel applications such as fire detection, gas analysis, multi-color imaging, multi-channel detectors, recognition of artificial objects in a natural environment, and facial recognition. However, these functions require additional filters or polarizers, which leads to high cost and technical difficulties related to integration of many different pixels in an array format. Plasmonic metamaterial absorbers (PMAs) can impart wavelength or polarization selectivity to conventional thermal IR detectors simply by controlling the surface geometry of the absorbers to produce surface plasmon resonances at designed wavelengths or polarizations. This enables integration of many different pixels in an array format without any filters or polarizers. We review our recent advances in wavelength- and polarization-selective thermal IR sensors using PMAs for multi-color or polarimetric imaging. The absorption mechanism defined by the surface structures is discussed for three types of PMAs-periodic crystals, metal-insulator-metal and mushroom-type PMAs-to demonstrate appropriate applications. Our wavelength- or polarization-selective uncooled IR sensors using various PMAs and multi-color image sensors are then described. Finally, high-performance mushroom-type PMAs are investigated. These advanced functional thermal IR detectors with wavelength or polarization selectivity will provide great benefits for a wide range of applications.

  17. Wavelength- or Polarization-Selective Thermal Infrared Detectors for Multi-Color or Polarimetric Imaging Using Plasmonics and Metamaterials

    Directory of Open Access Journals (Sweden)

    Shinpei Ogawa

    2017-05-01

    Full Text Available Wavelength- or polarization-selective thermal infrared (IR detectors are promising for various novel applications such as fire detection, gas analysis, multi-color imaging, multi-channel detectors, recognition of artificial objects in a natural environment, and facial recognition. However, these functions require additional filters or polarizers, which leads to high cost and technical difficulties related to integration of many different pixels in an array format. Plasmonic metamaterial absorbers (PMAs can impart wavelength or polarization selectivity to conventional thermal IR detectors simply by controlling the surface geometry of the absorbers to produce surface plasmon resonances at designed wavelengths or polarizations. This enables integration of many different pixels in an array format without any filters or polarizers. We review our recent advances in wavelength- and polarization-selective thermal IR sensors using PMAs for multi-color or polarimetric imaging. The absorption mechanism defined by the surface structures is discussed for three types of PMAs—periodic crystals, metal-insulator-metal and mushroom-type PMAs—to demonstrate appropriate applications. Our wavelength- or polarization-selective uncooled IR sensors using various PMAs and multi-color image sensors are then described. Finally, high-performance mushroom-type PMAs are investigated. These advanced functional thermal IR detectors with wavelength or polarization selectivity will provide great benefits for a wide range of applications.

  18. Short-wave infrared barriode detectors using InGaAsSb absorption material lattice matched to GaSb

    Energy Technology Data Exchange (ETDEWEB)

    Craig, A. P.; Percy, B.; Marshall, A. R. J. [Physics Department, Lancaster University, Lancaster LA1 4YB (United Kingdom); Jain, M. [Amethyst Research Ltd., Kelvin Campus, West of Scotland Science Park, Glasgow G20 0SP (United Kingdom); Wicks, G.; Hossain, K. [Amethyst Research, Inc., 123 Case Circle, Ardmore, Oklahoma 73401 (United States); Golding, T. [Amethyst Research Ltd., Kelvin Campus, West of Scotland Science Park, Glasgow G20 0SP (United Kingdom); Amethyst Research, Inc., 123 Case Circle, Ardmore, Oklahoma 73401 (United States); McEwan, K.; Howle, C. [Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ (United Kingdom)

    2015-05-18

    Short-wave infrared barriode detectors were grown by molecular beam epitaxy. An absorption layer composition of In{sub 0.28}Ga{sub 0.72}As{sub 0.25}Sb{sub 0.75} allowed for lattice matching to GaSb and cut-off wavelengths of 2.9 μm at 250 K and 3.0 μm at room temperature. Arrhenius plots of the dark current density showed diffusion limited dark currents approaching those expected for optimized HgCdTe-based detectors. Specific detectivity figures of around 7×10{sup 10} Jones and 1×10{sup 10} Jones were calculated, for 240 K and room temperature, respectively. Significantly, these devices could support focal plane arrays working at higher operating temperatures.

  19. In situ calibration of the foil detector for an infrared imaging video bolometer using a carbon evaporation technique

    Science.gov (United States)

    Mukai, K.; Peterson, B. J.; Takayama, S.; Sano, R.

    2016-11-01

    The InfraRed imaging Video Bolometer (IRVB) is a useful diagnostic for the multi-dimensional measurement of plasma radiation profiles. For the application of IRVB measurement to the neutron environment in fusion plasma devices such as the Large Helical Device (LHD), in situ calibration of the thermal characteristics of the foil detector is required. Laser irradiation tests of sample foils show that the reproducibility and uniformity of the carbon coating for the foil were improved using a vacuum evaporation method. Also, the principle of the in situ calibration system was justified.

  20. Use of an infrared detector to analyze the temperature evolution of a droplet impacting on a heating wall

    Science.gov (United States)

    Amiel, Clarisse; Le Clercq, Patrick; Ravel, Olivier; Lavergne, Gerard; Berthoumieu, Pierre; Farre, Jean A.

    2001-03-01

    The improvement of the combustion performance in combustor engines in terms of the reduction of the pollutant emissions is an important objective in Automotive and Aerospace Research and Development. Many phenomena occur during the spray injection in the combustor engine: droplet turbulent dispersion, droplet wall interaction, droplets interaction, droplet evaporation, primary and secondary breakup, auto- ignition, combustion, etc. To improve and to validate the heat exchange models between the droplet and a heated wall, an experimental set-up is developed at the ONERA Toulouse Centre on fundamental studies involving single droplets. An Infrared detector measures the temperature evolution of the surface droplet which impinges on a heated wall.

  1. Long-wavelength PtSi infrared detectors fabricated by incorporating a p(+) doping spike grown by molecular beam epitaxy

    Science.gov (United States)

    Lin, T. L.; Park, J. S.; George, T.; Jones, E. W.; Fathauer, R. W.; Maserjian, J.

    1993-01-01

    By incorporating a 1-nm-thick p(+) doping spike at the PtSi/Si interface, we have successfully demonstrated extended cutoff wavelengths of PtSi Schottky infrared detectors in the long wavelength infrared (LWIR) regime for the first time. The extended cutoff wavelengths resulted from the combined effects of an increased electric field near the silicide/Si interface due to the p(+) doping spike and the Schottky image force. The p(+) doping spikes were grown by molecular beam epitaxy at 450 C, using elemental boron as the dopant source, with doping concentrations ranging from 5 x 10 exp 19 to 2 x 10 exp 20/cu cm. Transmission electron microscopy indicated good crystalline quality of the doping spikes. The cutoff wavelengths were shown to increase with increasing doping concentrations of the p(+) spikes. Thermionic emission dark current characteristics were observed and photoresponses in the LWIR regime were demonstrated.

  2. High-Speed Incoming Infrared Target Detection by Fusion of Spatial and Temporal Detectors

    Science.gov (United States)

    Kim, Sungho

    2015-01-01

    This paper presents a method for detecting high-speed incoming targets by the fusion of spatial and temporal detectors to achieve a high detection rate for an active protection system (APS). The incoming targets have different image velocities according to the target-camera geometry. Therefore, single-target detector-based approaches, such as a 1D temporal filter, 2D spatial filter and 3D matched filter, cannot provide a high detection rate with moderate false alarms. The target speed variation was analyzed according to the incoming angle and target velocity. The speed of the distant target at the firing time is almost stationary and increases slowly. The speed varying targets are detected stably by fusing the spatial and temporal filters. The stationary target detector is activated by an almost zero temporal contrast filter (TCF) and identifies targets using a spatial filter called the modified mean subtraction filter (M-MSF). A small motion (sub-pixel velocity) target detector is activated by a small TCF value and finds targets using the same spatial filter. A large motion (pixel-velocity) target detector works when the TCF value is high. The final target detection is terminated by fusing the three detectors based on the threat priority. The experimental results of the various target sequences show that the proposed fusion-based target detector produces the highest detection rate with an acceptable false alarm rate. PMID:25815448

  3. Infrared detector Dewars - Increased LN2 hold time and vacuum jacket life spans

    Science.gov (United States)

    Jennings, D. E.; Boyd, W. J.; Blass, W. E.

    1976-01-01

    IR detector Dewars commonly suffer from shorter than desired LN2 hold times and insulation jacket vacuum corruption over relatively short time periods. In an attempt to solve this problem for a 9144 detector Dewar, small 1 liter/s appendage ion pumps were selected for continuous pumping of the vacuum jackets. This procedure extended LN2 hold times from 20 to 60 h and virtually eliminated vacuum jacket corruption. Thus the detector systems are usable continuously over periods of 6 months or more.

  4. Turn-key Near-Infrared Photon-Counting Detector Module for LIDAR Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Based on the prototype photon counter developed during Phase I, we will deliver a next-generation photon counting detector optimized for LIDAR applications within...

  5. An Implant-Passivated Blocked Impurity Band Germanium Detector for the Far Infrared Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to fabricate a germanium blocked-impurity-band (BIB) detector using a novel process which will enable us to: 1- fabricate a suitably-doped active layer...

  6. An Implant-Passivated Blocked Impurity Band Germanium Detector for the Far Infrared Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to investigate the feasibility of fabricating a germanium blocked-impurity-band (BIB) detector using a novel process which will enable us to: 1- fabricate...

  7. Improved mid infrared detector for high spectral or spatial resolution and synchrotron radiation use

    Science.gov (United States)

    Faye, Mbaye; Bordessoule, Michel; Kanouté, Brahim; Brubach, Jean-Blaise; Roy, Pascale; Manceron, Laurent

    2016-06-01

    When using bright, small effective size sources, such as synchrotron radiation light beam, for broadband spectroscopy at spectral or spatial high resolution for mid-IR FTIR measurements, a marked detectivity improvement can be achieved by setting up a device matching the detector optical étendue to that of the source. Further improvement can be achieved by reducing the background unmodulated flux and other intrinsic noise sources using a lower temperature cryogen, such as liquid helium. By the combined use of cooled apertures, cold reimaging optics, filters and adapted detector polarization, and preamplification electronics, the sensitivity of a HgCdTe photoconductive IR detector can be improved by a significant factor with respect to standard commercial devices (more than one order of magnitude on average over 6-20 μm region) and the usable spectral range extended to longer wavelengths. The performances of such an optimized detector developed on the AILES Beamline at SOLEIL are presented here.

  8. A kilo-pixel imaging system for future space based far-infrared observatories using microwave kinetic inductance detectors

    Science.gov (United States)

    Baselmans, J. J. A.; Bueno, J.; Yates, S. J. C.; Yurduseven, O.; Llombart, N.; Karatsu, K.; Baryshev, A. M.; Ferrari, L.; Endo, A.; Thoen, D. J.; de Visser, P. J.; Janssen, R. M. J.; Murugesan, V.; Driessen, E. F. C.; Coiffard, G.; Martin-Pintado, J.; Hargrave, P.; Griffin, M.

    2017-05-01

    Aims: Future astrophysics and cosmic microwave background space missions operating in the far-infrared to millimetre part of the spectrum will require very large arrays of ultra-sensitive detectors in combination with high multiplexing factors and efficient low-noise and low-power readout systems. We have developed a demonstrator system suitable for such applications. Methods: The system combines a 961 pixel imaging array based upon Microwave Kinetic Inductance Detectors (MKIDs) with a readout system capable of reading out all pixels simultaneously with only one readout cable pair and a single cryogenic amplifier. We evaluate, in a representative environment, the system performance in terms of sensitivity, dynamic range, optical efficiency, cosmic ray rejection, pixel-pixel crosstalk and overall yield at an observation centre frequency of 850 GHz and 20% fractional bandwidth. Results: The overall system has an excellent sensitivity, with an average detector sensitivity =3×10-19 WHz measured using a thermal calibration source. At a loading power per pixel of 50 fW we demonstrate white, photon noise limited detector noise down to 300 mHz. The dynamic range would allow the detection of 1 Jy bright sources within the field of view without tuning the readout of the detectors. The expected dead time due to cosmic ray interactions, when operated in an L2 or a similar far-Earth orbit, is found to be <4%. Additionally, the achieved pixel yield is 83% and the crosstalk between the pixels is <-30 dB. Conclusions: This demonstrates that MKID technology can provide multiplexing ratios on the order of a 1000 with state-of-the-art single pixel performance, and that the technology is now mature enough to be considered for future space based observatories and experiments.

  9. Advanced far infrared blocked impurity band detectors based on germanium liquid phase epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Christopher Sean [Univ. of California, Berkeley, CA (United States)

    1998-05-01

    This research has shown that epilayers with residual impurity concentrations of 5 x 1013 cm-3 can be grown by producing the purest Pb available in the world. These epilayers have extremely low minority acceptor concentrations, which is ideal for fabrication of IR absorbing layers. The Pb LPE growth of Ge also has the advantageous property of gettering Cu from the epilayer and the substrate. Epilayers have been grown with intentional Sb doping for IR absorption on lightly doped substrates. This research has proven that properly working Ge BIB detectors can be fabricated from the liquid phase as long as pure enough solvents are available. The detectors have responded at proper wavelengths when reversed biased even though the response did not quite reach minimum wavenumbers. Optimization of the Sb doping concentration should further decrease the photoionization energy of these detectors. Ge BIB detectors have been fabricated that respond to 60 cm-1 with low responsivity. Through reduction of the minority residual impurities, detector performance has reached responsivities of 1 A/W. These detectors have exhibited quantum efficiency and NEP values that rival conventional photoconductors and are expected to provide a much more sensitive tool for new scientific discoveries in a number of fields, including solid state studies, astronomy, and cosmology.

  10. Characterisation of an inhomogeneously irradiated microstrip detector using a fine spot infrared laser

    CERN Document Server

    Casse, G; Bowcock, T J V; Greenall, A; Phillips, JP; Turner, PR; Wright, V

    2001-01-01

    A prototype silicon microstrip detector for the LHCb vertex locator (VELO) has been partially irradiated using a 24 GeV/c proton beam at the CERN-PS accelerator. The detector possesses a radial strip geometry designed to measure the azimuthal coordinate (Phi) of tracks within the VELO. The peak fluence received by the detector was measured to be 4.6×10 14 p/cm 2 though the non-uniform nature of the exposure left part of the detector unirradiated. The inhomogeneous irradiation introduced a damage profile in the detector approximating to that expected in the VELO. High irradiation gradients are important to study as they can modify the electric field within the silicon. Of special interest are changes in the component of the electric field parallel to the strip plane but perpendicular to the strips which lead to systematic shifts in the reconstructed cluster position. If these (flux and position dependent) shifts are sufficiently large they could contribute to a degraded spatial resolution of the detector. In ...

  11. Design, Growth, and Characterization of Mid Infrared and Terahertz Detectors Based on Nanostructures

    Science.gov (United States)

    Choi, Jae Kyu

    In the first part of the dissertation, I present the design, growth, and characterization a multi-color quantum well infrared photodetecor (QWIP). The QWIP is based on GaAs/Al0.2Ga0.8As coupled double-quantum-well structure with asymmetric doping of the wells. The asymmetry resulted into a new property of the detector -- voltage tunability of the QWIP multicolor spectrum. Three major mechanisms contributing into the photoresponse were analyzed: 1) electron energy level shifting due to the quantum-confined Stark effect, 2) tunneling process at the triangular tip of barrier, which is known Fowler-Nordheim effect, and 3) thermoactivation processes. The experimental and theoretical results are in good agreement with the simulation results using Matlab and nextnano3 software. The QWIP structure was grown by the solid source molecular beam epitaxy, and was experimentally characterized by performing current-voltage characteristics and spectral photoresponse measurement. The effective voltage tunability and switchability of spectral photoresponse were demonstrated in the spectral range between 7.5 ˜ 11.1 mum. The low noise QWIP operation (at the dark current as low as 3 ?10-3 A/cm2) was demonstrated up to 60 K. The results are promising for development of accurate remote temperature sensing. In the second part, we present the results on design, fabrication, and characterization of a hot-electron bolometer based on low mobility 2-D electron gas (2-DEG) in an AlGaN/GaN heterostructure. The characterization of the hot-electron bolometer (HEB) demonstrated that we could simultaneously achieve the following conditions required for successful operation of 2-DEG HEB: 1) strong coupling to incident THz radiation due to strong Drude absorption; 2) significant THz heating of 2-DEG due to the small value of the electron heat capacity: and 3) high responsivity due to the strong temperature dependence of 2-DEG resistance. We identified THz response from our HEBs as a bolometric effect

  12. Design of a VDF/TrFE Copolymer-on-silicon pyroelectric sensor

    NARCIS (Netherlands)

    Setiadi, D.; Regtien, P.P.L.

    1994-01-01

    This paper presents a design of a VDF/TrFE copolymer-on-silicon pyroelectric sensor. For an optimal design of a VDF/TrFE-on-silicon pyroelectric sensor, the one-dimensional diffusion equation is solved for the pyroelectric multilayer structure. The output current of the sensor is calculated. Improve

  13. Dielectric and Pyroelectric Properties of La- and Pr-Modified Tungsten-Bronze Ferroelectrics

    Science.gov (United States)

    Parida, B. N.; Das, Piyush R.; Padhee, R.; Choudhary, R. N. P.

    2013-08-01

    The polycrystalline materials Li2Pb2R2W2Ti4Nb4O30 (R = La, Pr) of the tungsten-bronze structural family have been synthesized using a high- temperature mixed-oxide method. Room-temperature x-ray diffraction (XRD) analysis confirms the formation of single-phase compounds. Room-temperature scanning electron micrography of the pellet samples shows a uniform distribution of well-defined different sizes of grains on the surface of the samples, confirming the formation of single-phase compounds. Study of the frequency and temperature dependence of the dielectric constant and loss tangent suggests the existence of dielectric dispersion in the materials. The ferroelectric phase transition in the samples has been studied based on the variation of fitting parameters (calculated from a theoretical model) with temperature. Studies of pyroelectric properties [figure of merit (FOM) and coefficient] show that the materials have reasonably high FOM useful for pyroelectric detectors. The variation of alternating-current (AC) and direct-current (DC) conductivity with inverse absolute temperature (obtained from dielectric data) follows a typical Arrhenius relation. The low leakage current and negative temperature coefficient of resistance behavior of the samples have been verified from J- E plots.

  14. Investigation of pyroelectric electron emission from monodomain lithium niobate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Bourim, El Mostafa [Samsung Advanced Institute of Technology, U-Team, P.O. Box 111, Suwon, Kyongki 440-600 (Korea, Republic of)]. E-mail: em.bourim@samsung.com; Moon, Chang-Wook [Samsung Advanced Institute of Technology, U-Team, P.O. Box 111, Suwon, Kyongki 440-600 (Korea, Republic of); Lee, Seung-Woon [Samsung Advanced Institute of Technology, U-Team, P.O. Box 111, Suwon, Kyongki 440-600 (Korea, Republic of); Kyeong Yoo, In [Samsung Advanced Institute of Technology, U-Team, P.O. Box 111, Suwon, Kyongki 440-600 (Korea, Republic of)

    2006-09-01

    The behaviors of thermally stimulated electron emission from pyroelectric monodomain lithium niobate single crystal (LiNbO{sub 3}) were investigated by utilizing a Si p-n junction photodiode as electron detector and a receptive electron beam resist (E-beam resist) as electron collector. In high vacuum (10{sup -6} Torr), the pyroelectric electron emission (PEE) was found to depend on the exposed emitting polar crystal surface (+Z face or -Z face) and was significantly influenced by the emitter-electron receiver gap distances. Thus, the PEE from +Z face was detected during heating and was activated, in small gaps (<2 mm), by field emission effect on which was superposed an intense field ionization effect that primed intermittent runway ionizations (plasma breakdown into a glow discharge). In large gaps (>2 mm) the emission was simply mastered by field emission effect. Whereas, The PEE from -Z face was detected during cooling and was solely due to the field ionization effect. Therewith, for small gaps (<2 mm) the emission was governed by intermittent runway ionization ignitions resulting from a high ionization degree leading to dense plasma formation, and for large gaps (>2 mm) PEE was governed by field ionization generating a soft and continuous plasma ambient atmosphere. Significant decrease of electron emission current was observed from +Z face after successive thermal cycles. A fast and fully emission recovery was established after a brief exposure of crystal to a poor air vacuum of 10{sup -1} Torr.

  15. A kilo-pixel imaging system for future space based far-infrared observatories using microwave kinetic inductance detectors

    CERN Document Server

    Baselmans, J J A; Yates, S J C; Yurduseven, O; Llombart, N; Karatsu, K; Baryshev, A M; Ferrari, L; Endo, A; Thoen, D J; de Visser, P J; Janssen, R M J; Murugesan, V; Driessen, E F C; Coiffard, G; Martin-Pintado, J; Hargrave, P; Griffin, M

    2016-01-01

    Future astrophysics and cosmic microwave background space missions operating in the far-infrared to millimetre part of the spectrum will require very large arrays of ultra-sensitive detectors in combination with high multiplexing factors and efficient low- noise and low-power readout systems. We have developed a demonstrator system suitable for such applications. The system combines a 961 pixel imaging array based upon Microwave Kinetic Inductance Detectors (MKIDs) with a readout system capable of reading out all pixels simultaneously with only one readout cable pair and a single cryogenic amplifier. We evaluate, in a representative environment, the system performance in terms of sensitivity, dynamic range, optical efficiency, cosmic ray rejection, pixel-pixel crosstalk and overall yield at an observation frequency of 850 GHz. The overall system has an excellent sensitivity, with an average detector sensitivity NEP=2.8 +- 0.8 x 10^-19 W/rt(Hz) measured using a thermal calibration source. The dynamic range wou...

  16. Improving Pyroelectric Energy Harvesting Using a Sandblast Etching Technique

    Directory of Open Access Journals (Sweden)

    An-Shen Siao

    2013-09-01

    Full Text Available Large amounts of low-grade heat are emitted by various industries and exhausted into the environment. This heat energy can be used as a free source for pyroelectric power generation. A three-dimensional pattern helps to improve the temperature variation rates in pyroelectric elements by means of lateral temperature gradients induced on the sidewalls of the responsive elements. A novel method using sandblast etching is successfully applied in fabricating the complex pattern of a vortex-like electrode. Both experiment and simulation show that the proposed design of the vortex-like electrode improved the electrical output of the pyroelectric cells and enhanced the efficiency of pyroelectric harvesting converters. A three-dimensional finite element model is generated by commercial software for solving the transient temperature fields and exploring the temperature variation rate in the PZT pyroelectric cells with various designs. The vortex-like type has a larger temperature variation rate than the fully covered type, by about 53.9%.The measured electrical output of the vortex-like electrode exhibits an obvious increase in the generated charge and the measured current, as compared to the fully covered electrode, by of about 47.1% and 53.1%, respectively.

  17. Development of MEMS based pyroelectric thermal energy harvesters

    Science.gov (United States)

    Hunter, Scott R.; Lavrik, Nickolay V.; Bannuru, Thirumalesh; Mostafa, Salwa; Rajic, Slo; Datskos, Panos G.

    2011-06-01

    The efficient conversion of waste thermal energy into electrical energy is of considerable interest due to the huge sources of low-grade thermal energy available in technologically advanced societies. Our group at the Oak Ridge National Laboratory (ORNL) is developing a new type of high efficiency thermal waste heat energy converter that can be used to actively cool electronic devices, concentrated photovoltaic solar cells, computers and large waste heat producing systems, while generating electricity that can be used to power remote monitoring sensor systems, or recycled to provide electrical power. The energy harvester is a temperature cycled pyroelectric thermal-to-electrical energy harvester that can be used to generate electrical energy from thermal waste streams with temperature gradients of only a few degrees. The approach uses a resonantly driven pyroelectric capacitive bimorph cantilever structure that potentially has energy conversion efficiencies several times those of any previously demonstrated pyroelectric or thermoelectric thermal energy harvesters. The goals of this effort are to demonstrate the feasibility of fabricating high conversion efficiency MEMS based pyroelectric energy converters that can be fabricated into scalable arrays using well known microscale fabrication techniques and materials. These fabrication efforts are supported by detailed modeling studies of the pyroelectric energy converter structures to demonstrate the energy conversion efficiencies and electrical energy generation capabilities of these energy converters. This paper reports on the modeling, fabrication and testing of test structures and single element devices that demonstrate the potential of this technology for the development of high efficiency thermal-to-electrical energy harvesters.

  18. A Meliorated Multi-Frequency Band Pyroelectric Sensor.

    Science.gov (United States)

    Hsiao, Chun-Ching; Liu, Sheng-Yi; Siao, An-Shen

    2015-07-06

    This article proposes a meliorated multi-frequency band pyroelectric sensor for detecting subjects with various velocities, namely extending the sensing frequency under good performance from electrical signals. A tactic, gradually increasing thickness of the ZnO layers, is used for redeeming drawbacks of a thicker pyroelectric layer with a tardy response at a high-frequency band and a thinner pyroelectric layer with low voltage responsivity at a low-frequency band. The proposed sensor is built on a silicon substrate with a thermal isolation layer of a silicon nitride film, consisting of four pyroelectric layers with various thicknesses deposited by a sputtering or aerosol deposition (AD) method and top and bottom electrodes. The thinnest ZnO layer is deposited by sputtering, with a low thermal capacity and a rapid response shoulders a high-frequency sensing task, while the thicker ZnO layers are deposited by AD with a large thermal capacity and a tardy response shoulders a low-frequency sensing task. The fabricated device is effective in the range of 1 KHz~10 KHz with a rapid response and high voltage responsivity, while the ZnO layers with thicknesses of about 0.8 μm, 6 μm, 10 μm and 16 μm are used for fabricating the meliorated multi-frequency band pyroelectric sensor. The proposed sensor is successfully designed, analyzed, and fabricated in the present study, and can indeed extend the sensing range of the multi-frequency band.

  19. AUTHENTIC: a very low-cost infrared detector and camera system

    Science.gov (United States)

    Mansi, Mike V.; Brookfield, Martin; Porter, Stephen G.; Edwards, Ivan; Bold, Brendon; Shannon, John; Lambkin, Paul; Mathewson, Alan

    2003-01-01

    An Oxide over Titanium metal resistance bolometer technology developed by NMRC, Ireland) has been transferred to the X-FAB UK CMOS foundry at Plymouth, UK. Prototypes of the bolometers have been manufactured in the X-FAB production facility and tests show performance comparable with the NMRC prototypes. The bolometer design has been integrated with a CMOS read-out chip and the first wafers are currently being packaged for evaluation. The development of a low cost thermal imaging camera using the detector is under way. We present an overview of the detector and camera design, together with preliminary results from the detector test programme. The work is partly funded by the European Union IST programme.

  20. 线列TDI型红外探测器组件坏元替代方法%Alternative method of linear TDI infrared detector blind pixel

    Institute of Scientific and Technical Information of China (English)

    郭亮; 李冬冰; 杨微; 石纲; 孙玉杰

    2015-01-01

    The linear TDI infrared detector is widely used in many fields.Due to the influence of some factors such as work materials and manufacturing process,there are blind pixels in infrared detector.Blind pixels will cause image degradation and the distribution distortion of image gray,which affects the performance of infrared system.An alterna-tive method of blind pixel for 576 ×6 linear TDI infrared detector was introduced.Based on this method,blind pixels in channels of the linear TDI infrared detector can be replaced,which improves the image quality.%国产线列TDI型红外探测器组件在红外系统中的应用越来越广泛,但由于加工材料和制造工艺等因素的影响,探测器组件存在坏元,将造成图像质量下降,图像灰度分布失真,进而影响红外系统的性能。本文介绍了576×6线列TDI型红外探测器组件的读出电路坏元替代方法,采用该方法可进行线列TDI型红外探测器组件通道内的坏元替代,提高图像质量。

  1. Pyroelectric spectrum in Pb(Zr,Sn,Ti)O3 antiferroelectric- ferroelectric ceramics

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The pyroelectric effect of phase transition induced with temperature in Nb-modified Pb(Zr,Sn,Ti)O3 antiferroelectric-ferroelectric ceramics is studied. Experimental results reveal that the phase transitions are accompanied with marked pyroelectric peaks, there exists the close relation between the type of phase transition and the shape of pyroelectric peak. Because of the variations of phase transition, various pyroelectric spectra result. The pyroelectric spectrum can display the polarization effect and some inferior phase transitions with temperature variations, such as antiferroelectric AFEA-AFEB or ferroelectric FEL-FEH transition, which are not detected by the conventional dielectric measurement.

  2. Extraction of thermal parameters of microbolometer infrared detectors using electrical measurement

    Science.gov (United States)

    Karunasiri, R. P. G.; Xu, Gu; Chen, G. X.; Sridhar, U.

    1998-10-01

    The performance of microbolometer infrared sensors is typically characterized by its thermal time constant, heat capacitance, and thermal conductance. Therefore, the determination of these parameters accurately and efficiently is of considerable interest for the design and operation of microbolometer infrared sensors. Usually, the thermal time constant is obtained by measuring the frequency response of microbolometers under infrared excitation and the thermal conductance and capacity are extracted using electrical measurement. In this paper, a technique is described to extract all three parameters using a single electrical measurement. In the measurement, we have employed a Wheatstone Bridge consisting of a bolometer and three reference resistors. The resistance of the bolometer changes as a result of self-heating under an external bias which in turn generates an output voltage across the Bridge. The time dependence of the output voltage was used to extract thermal parameters of the bolometer. We believe this technique is useful in determining the thermal parameters of microbolometer based sensors.

  3. Near infrared single photon avalanche detector with negative feedback and self quenching

    Science.gov (United States)

    Linga, Krishna; Yevtukhov, Yuriy; Liang, Bing

    2009-08-01

    We present the design and development of a negative feedback devices using the internal discrete amplifier approach used for the development of a single photon avalanche photodetector in the near infrared wavelength region. This new family of photodetectors with negative feedback, requiring no quenching mechanism using Internal Discrete Amplification (IDA) mechanism for the realization of very high gain and low excess noise factor in the visible and near infrared spectral regions, operates in the non-gated mode under a constant bias voltage. The demonstrated device performance far exceeds any available solid state Photodetectors in the near infrared wavelength range. The measured devices have Gain > 2×105, Excess noise factor Lidar, free space optical communication, 3D imaging, industrial and scientific instrumentation, night vision, quantum cryptography, and other military, defence and aerospace applications.

  4. Proton irradiation results for long-wave HgCdTe infrared detector arrays for NEOCam

    CERN Document Server

    Dorn, M; McMurtry, C; Hartman, S; Mainzer, A; McKelvey, M; McMurray, R; Chevara, D; Rosser, J

    2016-01-01

    HgCdTe detector arrays with a cutoff wavelength of ~10 ${\\mu}$m intended for the NEOCam space mission were subjected to proton beam irradiation at the University of California Davis Crocker Nuclear Laboratory. Three arrays were tested - one with 800 $\\mu$m substrate intact, one with 30 $\\mu$m substrate, and one completely substrate-removed. The CdZnTe substrate, on which the HgCdTe detector is grown, has been shown to produce luminescence in shorter wave HgCdTe arrays that causes elevated signal in non-hit pixels when subjected to proton irradiation. This testing was conducted to ascertain whether or not full substrate removal is necessary. At the dark level of the dewar, we detect no luminescence in non-hit pixels during proton testing for both the substrate-removed detector array and the array with 30 ${\\mu}$m substrate. The detector array with full 800 ${\\mu}$m substrate exhibited substantial photocurrent for a flux of 103 protons/cm$^2$-s at a beam energy of 18.1 MeV (~ 750 e$^-$/s) and 34.4 MeV ($\\sim$ 6...

  5. Nano/microscale pyroelectric energy harvesting: challenges and opportunities

    Directory of Open Access Journals (Sweden)

    Devashish Lingam

    2013-12-01

    Full Text Available With the ever-growing demand for renewable energy sources, energy harvesting from natural resources has gained much attention. Energy sources such as heat and mechanical motion could be easily harvested based on pyroelectric, thermoelectric, and piezoelectric effects. The energy harvested from otherwise wasted energy in the environment can be utilized in self-powered micro and nano devices, and wearable electronics, which required only µW–mW power. This article reviews pyroelectric energy harvesting with an emphasis on recent developments in pyroelectric energy harvesting and devices at micro/nanoscale. Recent developments are presented and future challenges and opportunities for more efficient materials and devices with higher energy conversion efficiency are also discussed.

  6. Power maximization for pyroelectric, piezoelectric, and hybrid energy harvesting

    Science.gov (United States)

    Shaheen, Murtadha A.

    The goal of this dissertation consists of improving the efficiency of energy harvesting using pyroelectric and piezoelectric materials in a system by the proper characterization of electrical parameters, widening frequency, and coupling of both effects with the appropriate parameters. A new simple stand-alone method of characterizing the impedance of a pyroelectric cell has been demonstrated. This method utilizes a Pyroelectric single pole low pass filter technique, PSLPF. Utilizing the properties of a PSLPF, where a known input voltage is applied and capacitance C p and resistance Rp can be calculated at a frequency of 1 mHz to 1 Hz. This method demonstrates that for pyroelectric materials the impedance depends on two major factors: average working temperature, and the heating rate. Design and implementation of a hybrid approach using multiple piezoelectric cantilevers is presented. This is done to achieve mechanical and electrical tuning, along with bandwidth widening. In addition, a hybrid tuning technique with an improved adjusting capacitor method was applied. An toroid inductor of 700 mH is shunted in to the load resistance and shunt capacitance. Results show an extended frequency range up to 12 resonance frequencies (300% improvement) with improved power up to 197%. Finally, a hybrid piezoelectric and pyroelectric system is designed and tested. Using a voltage doubler, circuit for rectifying and collecting pyroelectric and piezoelectric voltages individually is proposed. The investigation showed that the hybrid energy is possible using the voltage doubler circuit from two independent sources for pyroelectrictity and piezoelectricity due to marked differences of optimal performance.

  7. Spatial solitons in biased photovoltaic photorefractive materials with the pyroelectric effect

    Energy Technology Data Exchange (ETDEWEB)

    Katti, Aavishkar; Yadav, R.A., E-mail: rayadav@bhu.ac.in

    2017-01-23

    Spatial solitons in biased photorefractive media due to the photovoltaic effect and the pyroelectric effect are investigated. The pyroelectric field considered is induced due to the heating by the incident beam's energy. These solitons can be called screening photovoltaic pyroelectric solitons. It is shown that the solitons can exist in the bright and dark realizations. The conditions for formation of these solitons are discussed. Relevant example is considered to illustrate the self trapping of such solitons. The external electric field interacts with the photovoltaic field and the pyroelectric field to either support or oppose the self trapping. - Highlights: • Effect of pyroelectric field on screening photovoltaic solitons is studied. • Illumination induced pyroelectric field is considered for the first time. • Self trapping depends on external, pyroelectric and photovoltaic space charge field.

  8. Monolithic dual-band HgCdTe infrared detector structure

    CSIR Research Space (South Africa)

    Parish, G

    1997-07-01

    Full Text Available A monolithic HgCdTe photoconductive device structure is presented that is suitable for dual-band optically registered infrared photodetection in the two atmospheric transmission windows of 3-5 mu m and 8-12 mu m, which correspond to the mid...

  9. Improved Response of ZnO Films for Pyroelectric Devices

    Directory of Open Access Journals (Sweden)

    Shih-Yuan Yu

    2012-12-01

    Full Text Available Increasing the temperature variation rate is a useful method for enhancing the response of pyroelectric devices. A three-dimensional ZnO film was fabricated by the aerosol deposition (AD rapid process using the shadow mask method, which induces lateral temperature gradients on the sidewalls of the responsive element, thereby increasing the temperature variation rate. To enhance the quality of the film and reduce the concentration of defects, the film was further treated by laser annealing, and the integration of a comb-like top electrode enhanced the voltage response and reduced the response time of the resulting ZnO pyroelectric devices.

  10. Pyroelectric Energy Harvesting: With Thermodynamic-Based Cycles

    Directory of Open Access Journals (Sweden)

    Saber Mohammadi

    2012-01-01

    Full Text Available This work deals with energy harvesting from temperature variations using ferroelectric materials as a microgenerator. The previous researches show that direct pyroelectric energy harvesting is not effective, whereas thermodynamic-based cycles give higher energy. Also, at different temperatures some thermodynamic cycles exhibit different behaviours. In this paper pyroelectric energy harvesting using Lenoir and Ericsson thermodynamic cycles has been studied numerically and the two cycles were compared with each other. The material used is the PMN-25 PT single crystal that is a very interesting material in the framework of energy harvesting and sensor applications.

  11. Increasing sensitivity and angle-of-view of mid-wave infrared detectors by integration with dielectric microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Kenneth W., E-mail: kenneth.allen@gtri.gatech.edu; Astratov, Vasily N., E-mail: astratov@uncc.edu [Department of Physics and Optical Science, Center for Optoelectronics and Optical Communications, University of North Carolina at Charlotte, Charlotte, North Carolina 28223-0001 (United States); Air Force Research Laboratory, Sensors Directorate, Wright Patterson AFB, Ohio 45433 (United States); UES, Dayton, Ohio 45433 (United States); Abolmaali, Farzaneh [Department of Physics and Optical Science, Center for Optoelectronics and Optical Communications, University of North Carolina at Charlotte, Charlotte, North Carolina 28223-0001 (United States); Duran, Joshua M.; Ariyawansa, Gamini; Limberopoulos, Nicholaos I. [Air Force Research Laboratory, Sensors Directorate, Wright Patterson AFB, Ohio 45433 (United States); Urbas, Augustine M. [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Ohio 45433 (United States)

    2016-06-13

    We observed up to 100 times enhancement of sensitivity of mid-wave infrared photodetectors in the 2–5 μm range by using photonic jets produced by sapphire, polystyrene, and soda-lime glass microspheres with diameters in the 90–300 μm range. By finite-difference time-domain (FDTD) method for modeling, we gain insight into the role of the microspheres refractive index, size, and alignment with respect to the detector mesa. A combination of enhanced sensitivity with angle-of-view (AOV) up to 20° is demonstrated for individual photodetectors. It is proposed that integration with microspheres can be scaled up for large focal plane arrays, which should provide maximal light collection efficiencies with wide AOVs, a combination of properties highly attractive for imaging applications.

  12. Feasibility Study for a Dual Field of View-Single Detector Array Infrared System.

    Science.gov (United States)

    1974-06-01

    the background is shown in Figure 2-8. In this system the field stop is scare I with a vertical slit and essentially all the energy falling on the...cylindrical mirror will be o focused as a vertical iine on the detector array. Several of the previous problems have been solved in this system. The...patterns Limillid only by DAC, AD,,.J Access y u, limited by speed. anid Display Mtsaitor strict possible formats. xalbe Modification of timing salto

  13. Room temperature detector array technology for the terahertz to far-infrared.

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, Ryan; Shaw, Michael; Zhang, X.; Tao, Hu; Lentine, Anthony L.; Wright, Jeremy Benjamin; Shaner, Eric Arthur; Trotter, Douglas Chandler; Averitt, Richard D.; Kadlec, Emil G; Rakich, Peter T.

    2011-10-01

    Thermal detection has made extensive progress in the last 40 years, however, the speed and detectivity can still be improved. The advancement of silicon photonic microring resonators has made them intriguing for detection devices due to their small size and high quality factors. Implementing silicon photonic microring or microdisk resonators as a means of a thermal detector gives rise to higher speed and detectivity, as well as lower noise compared to conventional devices with electrical readouts. This LDRD effort explored the design and measurements of silicon photonic microdisk resonators used for thermal detection. The characteristic values, consisting of the thermal time constant ({tau} {approx} 2 ms) and noise equivalent power were measured and found to surpass the performance of the best microbolometers. Furthermore the detectivity was found to be D{sub {lambda}} = 2.47 x 10{sup 8} cm {center_dot} {radical}Hz/W at 10.6 {mu}m which is comparable to commercial detectors. Subsequent design modifications should increase the detectivity by another order of magnitude. Thermal detection in the terahertz (THz) remains underdeveloped, opening a door for new innovative technologies such as metamaterial enhanced detectors. This project also explored the use of metamaterials in conjunction with a cantilever design for detection in the THz region and demonstrated the use of metamaterials as custom thin film absorbers for thermal detection. While much work remains to integrate these technologies into a unified platform, the early stages of research show promising futures for use in thermal detection.

  14. The Mid-Infrared Instrument for the James Webb Space Telescope, VII: The MIRI Detectors

    CERN Document Server

    Rieke, G H; Morrison, Jane E; Bergeron, L; Bouchet, Patrice; Garcıa-Marın, Macarena; Greene, T P; Regan, M W; Sukhatme, K G; Walker, Helen

    2015-01-01

    The MIRI Si:As IBC detector arrays extend the heritage technology from the Spitzer IRAC arrays to a 1024 x 1024 pixel format. We provide a short discussion of the principles of operation, design, and performance of the individual MIRI detectors, in support of a description of their operation in arrays provided in an accompanying paper (Ressler et al. (2015)). We then describe modeling of their response. We find that electron diffusion is an important component of their performance, although it was omitted in previous models. Our new model will let us optimize the bias voltage while avoiding avalanche gain. It also predicts the fraction of the IR-active layer that is depleted (and thus contributes to the quantum efficiency) as signal is accumulated on the array amplifier. Another set of models accurately predicts the nonlinearity of the detector-amplifier unit and has guided determination of the corrections for nonlinearity. Finally, we discuss how diffraction at the interpixel gaps and total internal reflecti...

  15. Optical characteristics of p-type GaAs-based semiconductors towards applications in photoemission infrared detectors

    Science.gov (United States)

    Lao, Y. F.; Perera, A. G. U.; Wang, H. L.; Zhao, J. H.; Jin, Y. J.; Zhang, D. H.

    2016-03-01

    Free-carrier effects in a p-type semiconductor including the intra-valence-band and inter-valence-band optical transitions are primarily responsible for its optical characteristics in infrared. Attention has been paid to the inter-valence-band transitions for the development of internal photoemission (IPE) mid-wave infrared (MWIR) photodetectors. The hole transition from the heavy-hole (HH) band to the spin-orbit split-off (SO) band has demonstrated potential applications for 3-5 μm detection without the need of cooling. However, the forbidden SO-HH transition at the Γ point (corresponding to a transition energy Δ0, which is the split-off gap between the HH and SO bands) creates a sharp drop around 3.6 μm in the spectral response of p-type GaAs/AlGaAs detectors. Here, we report a study on the optical characteristics of p-type GaAs-based semiconductors, including compressively strained InGaAs and GaAsSb, and a dilute magnetic semiconductor, GaMnAs. A model-independent fitting algorithm was used to derive the dielectric function from experimental reflection and transmission spectra. Results show that distinct absorption dip at Δ0 is observable in p-type InGaAs and GaAsSb, while GaMnAs displays enhanced absorption without degradation around Δ0. This implies the promise of using GaMnAs to develop MWIR IPE detectors. Discussions on the optical characteristics correlating with the valence-band structure and free-hole effects are presented.

  16. C-RED One : the infrared camera using the Saphira e-APD detector

    Science.gov (United States)

    Greffe, Timothée.; Feautrier, Philippe; Gach, Jean-Luc; Stadler, Eric; Clop, Fabien; Lemarchand, Stephane; Boutolleau, David; Baker, Ian

    2016-08-01

    Name for Person Card: Observatoire de la Côte d'Azur First Light Imaging' C-RED One infrared camera is capable of capturing up to 3500 full frames per second with a sub-electron readout noise and very low background. This breakthrough has been made possible thanks to the use of an e- APD infrared focal plane array which is a real disruptive technology in imagery. C-RED One is an autonomous system with an integrated cooling system and a vacuum regeneration system. It operates its sensor with a wide variety of read out techniques and processes video on-board thanks to an FPGA. We will show its performances and expose its main features. The project leading to this application has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement N° 673944.

  17. TEM study on Si0.65Ge0.35/p-Si HIP infrared detector

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Microstructure of P+ -Si0.65Ge0.35/p-Si HIP infrared detector has been studied by using localization cross-section transmission electron microscopy. The photosensitive region of the detector consists of 6 P+ -Si0.65Ge0.35 layers and 5 UD-Si layers, whichare flat and have thickness of 6 nm and 32 nm, respectively. A stress field exists on the interface between Si0.65Ge0.35 and UD-Si layers, but no any crystal defect has been found in this region, except the edges of this region. Both Si0.65Ge0.35 and UD-Si layers on amorphous SiO2 layer consist of polycrystals and are in wave. There is defect area in the edges of photosensitive region.The area appears in a shape of inverse triangle and the maximum width is less than 120 nm. The crystal defects are stacking faults and microtwins.

  18. Metal-Organic Vapor Phase Epitaxial Reactor for the Deposition of Infrared Detector Materials

    Science.gov (United States)

    2015-04-09

    ADDRESS (ES) U.S. Army Research Office P.O. Box 12211 Research Triangle Park , NC 27709-2211 Epitaxial reactor, MOCVD, Infrared Materials, CdTe and...researchers from First Solar in depositing single crystal solar cell materials. A research contract worth over $150K was awarded to RPI b First Solar based on...Administrative Support Army Contracting Command - APG Research Triangle Park Division TEL: (919) 549-4269 FAX: (919) 549-4388 Table of

  19. Comparison of Thermal Detector Arrays for Off-Axis THz Holography and Real-Time THz Imaging.

    Science.gov (United States)

    Hack, Erwin; Valzania, Lorenzo; Gäumann, Gregory; Shalaby, Mostafa; Hauri, Christoph P; Zolliker, Peter

    2016-02-06

    In terahertz (THz) materials science, imaging by scanning prevails when low power THz sources are used. However, the application of array detectors operating with high power THz sources is increasingly reported. We compare the imaging properties of four different array detectors that are able to record THz radiation directly. Two micro-bolometer arrays are designed for infrared imaging in the 8-14 μm wavelength range, but are based on different absorber materials (i) vanadium oxide; (ii) amorphous silicon; (iii) a micro-bolometer array optimized for recording THz radiation based on silicon nitride; and (iv) a pyroelectric array detector for THz beam profile measurements. THz wavelengths of 96.5 μm, 118.8 μm, and 393.6 μm from a powerful far infrared laser were used to assess the technical performance in terms of signal to noise ratio, detector response and detectivity. The usefulness of the detectors for beam profiling and digital holography is assessed. Finally, the potential and limitation for real-time digital holography are discussed.

  20. Comparison of Thermal Detector Arrays for Off-Axis THz Holography and Real-Time THz Imaging

    Directory of Open Access Journals (Sweden)

    Erwin Hack

    2016-02-01

    Full Text Available In terahertz (THz materials science, imaging by scanning prevails when low power THz sources are used. However, the application of array detectors operating with high power THz sources is increasingly reported. We compare the imaging properties of four different array detectors that are able to record THz radiation directly. Two micro-bolometer arrays are designed for infrared imaging in the 8–14 μm wavelength range, but are based on different absorber materials (i vanadium oxide; (ii amorphous silicon; (iii a micro-bolometer array optimized for recording THz radiation based on silicon nitride; and (iv a pyroelectric array detector for THz beam profile measurements. THz wavelengths of 96.5 μm, 118.8 μm, and 393.6 μm from a powerful far infrared laser were used to assess the technical performance in terms of signal to noise ratio, detector response and detectivity. The usefulness of the detectors for beam profiling and digital holography is assessed. Finally, the potential and limitation for real-time digital holography are discussed.

  1. An Array of One-Dimensional Porous Silicon Photonic Crystal Reflector Islands for a Far-Infrared Image Detector

    Institute of Scientific and Technical Information of China (English)

    MIAO Feng-Juan; ZHANG Jie; XU Shao-Hui; WANG Lian-Wei; CHU Jun-Hao; CAO Zhi-Shen; ZHAN Peng; WANG Zhen-Lin

    2009-01-01

    @@ With the aid of photolithography, an array of one-dimensional porous silicon photonic crystal reflector islands for a far infrared image detector ranging from 10μm to 14μm is successfully fabricated. Silicon nitride formed by low pressure chemical vapor deposition (LPCVD) was used as the masking layer for the island array formation. After etching, the microstructures were examined by a scanning electron microscope and the optical properties were studied by Fourier transform infrared spectroscopy, the result indicates that the multilayer structure could be obtained in the perpendicular direction via periodically alternative etching current in each pre-patteru. At the same time, the island array has a well-proportioned lateral etching effect, which is very useful for the thermal isolation in lateral orientation of the application in devices. It is concluded that regardless of the absorption of the deposition layer on the substrate, the localized photonic crystalline islands have higher reflectivity. The designed islands structure not only prevents the cracking of the porous silicon layers but is also useful for the application in the cold part for the sensor devices and the interconnection of each pixel.

  2. InAs/GaSb type-II superlattice infrared detectors: three decades of development

    Science.gov (United States)

    Rogalski, A.; Kopytko, M.; Martyniuk, P.

    2017-02-01

    Recently, there has been considerable progress towards III-V antimonide-based low dimensional solids development and device design innovations. From a physics point of view, the type-II InAs/GaSb superlattice is an extremely attractive proposition. Their development results from two primary motivations: the perceived challenges of reproducibly fabricating high-operability HgCdTe FPAs at reasonable cost and theoretical predictions of lower Auger recombination for type-II superlattice (T2SL) detectors compared to HgCdTe. Lower Auger recombination should be translated into a fundamental advantage for T2SL over HgCdTe in terms of lower dark current and/or higher operating temperature, provided other parameters such as Shockley-Read-Hall lifetime are equal. Based on these promising results it is obvious now that the InAs/GaSb superlattice technology is competing with HgCdTe third generation detector technology with the potential advantage of standard III-V technology to be more competitive in costs and as a consequence series production pricing. Comments to the statement whether the superlattice IR photodetectors can outperform the "bulk" narrow gap HgCdTe detectors is one of the most important questions for the future of IR photodetectors presented by Rogalski at the April 2006 SPIE meeting in Orlando, Florida, are more credible today and are presented in this paper. It concerns the trade-offs between two most competing IR material technologies: InAs/GaSb type-II superlattices and HgCdTe ternary alloy system.

  3. Prospective sur les besoins « défense » en détecteurs infrarougeMid-term defence needs for infrared detectors

    Science.gov (United States)

    Peyrard, Jean-Christophe

    2003-12-01

    In this paper, we propose to present the prospects for mid-term needs for infrared detectors. These needs are derived from expected evolutions in imaging techniques as well as from operational requirements. The main trends that shall allow the direct development in infrared detection are as much the pursuit of greater range, a better discrimination of targets, as the efforts to minimize cost, volume, weigh and consumption. These trends will lead to an examination of the specific needs for some kind of 'smart' infrared detector. Among these applications, we will investigate more deeply the technological requirements for flash and 3D imaging, hyperspectral and uncooled imaging. To cite this article: J.-C. Peyrard, C. R. Physique 4 (2003).

  4. Impact of three-dimensional geometry on the performance of isolated electron-injection infrared detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fathipour, Vala; Jang, Sung Jun; Nia, Iman Hassani; Mohseni, Hooman, E-mail: hmohseni@northwestern.edu [Bio-Inspired Sensors and Optoelectronics Laboratory, Northwestern University, 2145 Sheridan Rd, Evanston, Illinois 60208 (United States)

    2015-01-12

    We present a quantitative study of the influence of three-dimensional geometry of the isolated electron–injection detectors on their characteristics. Significant improvements in the device performance are obtained as a result of scaling the injector diameter with respect to the trapping/absorbing layer diameters. Devices with about ten times smaller injector area with respect to the trapping/absorbing layer areas show more than an order of magnitude lower dark current, as well as an order of magnitude higher optical gain compared with devices of same size injector and trapping/absorbing layer areas. Devices with 10 μm injector diameter and 30 μm trapping/absorbing layer diameter show an optical gain of ∼2000 at bias voltage of −3 V with a cutoff wavelength of 1700 nm. Analytical expressions are derived for the electron-injection detector optical gain to qualitatively explain the significance of scaling the injector with respect to the absorber.

  5. Short wave infrared InGaAs focal plane arrays detector: the performance optimization of photosensitive element

    Science.gov (United States)

    Gao, Xin-jiang; Tang, Zun-lie; Zhang, Xiu-chuan; Chen, Yang; Jiang, Li-qun; Cheng, Hong-bing

    2009-07-01

    Significant progress has been achieved in technology of the InGaAs focal plane arrays (FPA) detector operating in short wave infrared (SWIR) last two decades. The no cryogenic cooling, low manufacturing cost, low power, high sensitivity and maneuverability features inherent of InGaAs FPA make it as a mainstream SWIR FPA in a variety of critical military, national security, aerospace, telecommunications and industrial applications. These various types of passive image sensing or active illumination image detecting systems included range-gated imaging, 3-Dimensional Ladar, covert surveillance, pulsed laser beam profiling, machine vision, semiconductor inspection, free space optical communications beam tracker, hyperspectroscopy imaging and many others. In this paper the status and perspectives of hybrid InGaAs FPA which is composed of detector array (PDA) and CMOS readout integrate circuit (ROIC) are reviewed briefly. For various low light levels applications such as starlight or night sky illumination, we have made use of the interface circuit of capacitive feedback transimpedance amplifier (CTIA) in which the integration capacitor was adjustable, therefore implements of the physical and electrical characteristics matches between detector arrays and readout intergrate circuit was achieved excellently. Taking into account the influences of InGaAs detector arrays' optoelectronic characteristics on performance of the FPA, we discussed the key parameters of the photodiode in detailed, and the tradeoff between the responsivity, dark current, impedance at zero bias and junction capacitance of photosensitive element has been made to root out the impact factors. As a result of the educed approach of the photodiode's characteristics optimizing which involve with InGaAs PDA design and process, a high performance InGaAs FPA of 30um pixel pitch and 320×256 format has been developed of which the response spectrum range over 0.9um to 1.7um, the mean peak detectivity (λ=1.55

  6. Advances in research and development homojunction and quantum-well infrared detectors

    CERN Document Server

    Francombe, Maurice H

    1995-01-01

    Physics of Thin Films is one of the longest running continuing series in thin film science, consisting of twenty volumes since 1963. The series contains quality studies of the properties of various thinfilms materials and systems.In order to be able to reflect the development of today''s science and to cover all modern aspects of thin films, the series, starting with Volume 20, has moved beyond the basic physics of thin films. It now addresses the most important aspects of both inorganic and organic thin films, in both their theoretical as well as technological aspects. Therefore, in order to reflect the modern technology-oriented problems, the title has been slightly modified from Physics of Thin Films to Thin Films.Key Features* Discusses the latest research about structure, physics, and infrared photoemissive behavior of heavily doped silicon homojunctions and Ge and GaAs-based alloy junctions* Reviews the current status of SiGe/Si quantum wells for infrared detection* Discusses key developments in the gro...

  7. A Meliorated Multi-Frequency Band Pyroelectric Sensor

    Directory of Open Access Journals (Sweden)

    Chun-Ching Hsiao

    2015-07-01

    Full Text Available This article proposes a meliorated multi-frequency band pyroelectric sensor for detecting subjects with various velocities, namely extending the sensing frequency under good performance from electrical signals. A tactic, gradually increasing thickness of the ZnO layers, is used for redeeming drawbacks of a thicker pyroelectric layer with a tardy response at a high-frequency band and a thinner pyroelectric layer with low voltage responsivity at a low-frequency band. The proposed sensor is built on a silicon substrate with a thermal isolation layer of a silicon nitride film, consisting of four pyroelectric layers with various thicknesses deposited by a sputtering or aerosol deposition (AD method and top and bottom electrodes. The thinnest ZnO layer is deposited by sputtering, with a low thermal capacity and a rapid response shoulders a high-frequency sensing task, while the thicker ZnO layers are deposited by AD with a large thermal capacity and a tardy response shoulders a low-frequency sensing task. The fabricated device is effective in the range of 1 KHz~10 KHz with a rapid response and high voltage responsivity, while the ZnO layers with thicknesses of about 0.8 μm, 6 μm, 10 μm and 16 μm are used for fabricating the meliorated multi-frequency band pyroelectric sensor. The proposed sensor is successfully designed, analyzed, and fabricated in the present study, and can indeed extend the sensing range of the multi-frequency band.

  8. Research on Spectral Response of an Infrared Detector%一种红外探测器的光谱响应研究

    Institute of Scientific and Technical Information of China (English)

    秦玉伟

    2012-01-01

    A new photoelectric detection system was designed by using Fourier transform infrared spectrometer advantages to detect the infrared detector spectral response. Through the measurement of the infrared interference signals, to Fourier transform, then the spectral response degree which is the important technical indexes of infrared detector performance could be got. This system in measurement of infrared spectral response, inherited the advantages and function of the Fourier transform infrared spectrometer. It realized the measuring high resolution, high accuracy and good stability.%针对傅里叶变换红外光谱仪的优点,测量红外探测器的光谱响应,设计一套新的光电检测系统.通过对测量所得红外干涉信号进行傅里叶变换,得到评判红外探测器性能重要技术指标的光谱响应度.系统在红外探测器光谱响应的测量上,继承了傅里叶变换红外光谱仪的功能和优点,实现了测量分辨率高、精度高和稳定性好.

  9. Development of ultra pure germanium epi layers for blocked impurity band far infrared detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, M.P.

    1991-05-01

    The main goals of this paper are: (1) To develop a low-pressure CVD (LPCVD) process that allows epitaxial growth at lower temperatures. Lower temperatures will allow the achievement of a sharp dopant profile at the substrate/epi-layer interface. Less out-diffusion from the substrate would allow the use of thinner epitaxial layers, which would lead to a larger depletion width in the photoactive region. LPCVD also avoids, to a great extent, gas-phase nucleation, which would cause Ge particulates to fall onto the wafer surface during growth. (2) To reduce high levels of oxygen and copper present at the wafer interface, as observed by secondary ion mass spectroscopy (SIMS). In order to achieve high-quality epitaxial layers, it is imperative that the substrate surface be of excellent quality. (3) To make and test detectors, after satisfactory epitaxial layers have been made.

  10. Photoresponse enhancement in graphene/silicon infrared detector by controlling photocarrier collection

    Science.gov (United States)

    Tang, Xin; Zhang, Hengkai; Tang, Xiaobing; Lai, King W. C.

    2016-07-01

    Graphene/silicon junction based photodetectors have attracted great interest due to their superior characteristics like large photosensitive area, fast photocarrier collection and low dark current. Currently, the weak optical absorption and short photocarrier lifetime of graphene remain major limitations for detection of infrared light with wavelengths above 1.2 μm. Here, we elucidate the mechanism of photocarrier transport in graphene/silicon junction based photodetector and propose a theoretical model to study the design and effect of finger-electrode structures on the photocurrent in graphene. We demonstrate that the top finger-like electrode in graphene/silicon photodetector can be designed to enhance the photocarrier collection efficiency in graphene by reducing the average transport distance of photocarriers. Therefore, the photoresponsivity of the graphene/silicon junction based photodetector can be increased. Our results have successfully demonstrated that by optimizing the design of finger electrodes, 4 times enhancement of photocurrents in graphene can be obtained at room temperature.

  11. Pyroelectric and dielectric properties of lead-free ferroelectric Ba{sub 3}Nb{sub 2}O{sub 8} ceramic

    Energy Technology Data Exchange (ETDEWEB)

    Pati, Biswajit [Department of Physics, Institute of Technical Education and Research, Siksha O Anusandhan University, Bhubaneswar 751030 (India); Department of Physics, Government Junior College, Bhawanipatna, Kalahandi 766001 (India); Choudhary, R.N.P., E-mail: crnpfl@gmail.com [Department of Physics, Institute of Technical Education and Research, Siksha O Anusandhan University, Bhubaneswar 751030 (India); Das, Piyush R.; Parida, B.N.; Padhee, R. [Department of Physics, Institute of Technical Education and Research, Siksha O Anusandhan University, Bhubaneswar 751030 (India)

    2014-04-01

    Graphical abstract: - Highlights: • Barium orthoniobate (lead-free perovskite) crystallizes as palmierite with structural stability. • The material exhibits ferroelectric phase transition of diffuse-type suitable for devices. • The low values of ε{sub r} and tan δ at high frequencies makes it a potential candidate for microwave applications. • The material has very good pyroelectric properties for detector application. • The material exhibits smaller value of dc activation energy. - Abstract: The present study highlights ferroelectric phase transition, dielectric, pyroelectric properties and conduction mechanism of highly crystallized barium orthoniobate (Ba{sub 3}Nb{sub 2}O{sub 8}) ceramic, prepared by a solid-state reaction technique. X-ray diffraction studies show the formation of a single-phase compound in hexagonal crystal system. Detailed studies of dielectric parameters (ε{sub r} and tan δ) of the compound as a function of temperature and frequency reveal their independence over a wide range of temperature and frequency. An anomaly in ε{sub r} suggests the possible existence of a ferroelectric–paraelectric phase transition of diffuse-type in the material. The low dielectric loss and moderate relative permittivity make this material (with certain modification) a potential candidate for microwave applications. Studies of pyroelectric properties reveal that the materials have reasonably high figure of merit useful for fabrication of pyroelectric detectors. The low-leakage current and negative temperature coefficient of resistance (NTCR) behavior of the sample have been verified from J–E plots. The nature of variation of dc conductivity with temperature confirms the Arrhenius and NTCR behavior of the material.

  12. Low-volume aluminum and aluminum / titanium nitride bilayer lumped-element kinetic inductance detectors for far-infrared astronomy

    Science.gov (United States)

    Glenn, Jason; Fyhrie, Adalyn; Wheeler, Jordan; Day, Peter K.; Eom, Byeong H.; Leduc, Henry G.

    2016-07-01

    We present the design and characterization of low-volume, lumped-element aluminum kinetic inductance de- tectors for sensitive far-infrared astronomy observations. The lumped-element kinetic inductance detectors are comprised of meandered inductors that serve as radiation absorbers in parallel with interdigitated capacitors, forming high quality factor resonators. Low inductor volumes lead to low noise equivalent powers by raising quasiparticles densities, and hence responsivities, with respect to larger volumes. Low volumes are achieved with thin (20 nm), narrow (150 nm) inductors. The interdigitated capacitor architecture is designed to mitigate two-level system noise by lowering electric fields in the silicon substrate. Resonance frequencies are in the range of 190 to 500 MHz, with measured internal quality factors in excess of 1 x 105. In a prior incarnation, a titanium nitride layer on top of the aluminum served as a protective layer, but complicated the superconducting proper- ties. These results were reported previously. In the current incarnation, the aluminum layer is left bare with no titanium nitride over-layer. The results for these bare aluminum devices include a yield of 88%, frequency responsivity of 109 W-1, and noise equivalent power of 1 x 10-17 W Hz-1/2 for a 350μm array. There is no evidence for 1=f noise down to at least 200 mHz. The sensitivity is currently limited by white noise, very likely from stray light in the testbed; for this detector design, sensitivities limited by generation-recombination noise in a lower-background environment should be several orders of magnitude lower.

  13. Design Optimization of Pixel Structure for α-Si based Uncooled Infrared Detector

    Directory of Open Access Journals (Sweden)

    Sudha Gupta

    2013-11-01

    Full Text Available In this paper authors present the design and simulation results achieved for pixel structure of amorphous Si (α-Si based bolometer array. Most uncooled IR detectors in the world are based on VOx material. But this is not a standard material in IC technology and has many inherent disadvantages. The α-Si, an alternative material with high TCR is becoming as popular. However, large TCR values, in this material are achieved only in films of high resistivity. To achieve TCR value more than 2.5%/K, α-Si film resistivity is ~ 80 ohms-cm. This gives rise to very large pixel resistance of the order of 100 Mega ohms depending upon the design of the leg structure. This high pixel resistance causes very large noise and hence lower sensitivity. If leg width or membrane thickness is increased in order to reduce the pixel resistance, then this results in higher thermal conductance which also decreases sensitivity. To overcome this problem, pixel structure is so designed that within a pixel, only part of the electrical conduction is through α-Si and rest is through metal. Simulation using Coventorware software has been done to optimize pixel resistance as well as thermal conductance through legs so that maximum sensitivity could be obtained. Optimization is also carried out in order to reduce sensitivity of pixel resistance to variation in material resistivity.

  14. Improvement of infrared single-photon detectors absorptance by integrated plasmonic structures

    CERN Document Server

    Csete, M; Szalai, A; Najafi, F; Berggren, K K

    2012-01-01

    The absorptance of p-polarized light in superconducting-nanowire single-photon detectors (SNSPDs) was improved by integrating (1) ~quarter-wavelength nano-optical cavity closed by a gold reflector (OC-SNSPD), (2) nano-cavity-array closed by vertical and horizontal gold segments (NCAI-SNSPD), and (3) nano-cavity-deflector-array consisting of longer vertical gold segments (NCDAI-SNSPD) into short- (p-) and long- (3p-) periodic niobium-nitride (NbN) stripe-patterns. In OC-SNSPDs the highest absorptance is observable at perpendicular incidence onto NbN stripes in P-orientation due to E-field concentration at the bottom of nano-optical cavities. In short-periodic NCAI-SNSPDs off-axis illumination results in almost polar-angle-independent perfect absorptance due to collective resonances on plasmonic MIM nano-cavity-arrays in S-orientation. In long-periodic NCAI-SNSPDs the surface wave-excitation phenomena promoting EM-field transportation to the NbN stripes in S-orientation are capable of resulting in local absorpt...

  15. Modeling and optimization of InGaAs infrared photovoltaic detectors

    CERN Document Server

    Piotrowski, J; Reginski, K

    2000-01-01

    The performance of In sub x Ga sub 1 sub - sub x As detectors operating in the 2-3.4 mu m spectral range and temperature of 300 K has been analyzed theoretically as a function of wavelength, band gap and doping level with special emphasis on 2-2.5 mu m and 3-3.5 mu m atmospheric window devices. The calculations show that the dominant generation-recombination mechanism in p-type, intrinsic and in a lightly doped n-type InGaAs is the spin split-off band Auger process (AS). Since the AS generation increases with the square of the hole concentration, the minimum thermal generation and the best performance can be obtained using moderately doped n-type material as the absorber region of a photovoltaic device. In principle, the ultimate performance can be achieved in the optimized homojunction devices with relatively thick n-type absorber region forming n-p junction with a thin p-type material. N-type doping of absorber region of InGaAs photodiodes at 300 K changes from 1x10 sup 1 sup 4 to 5.2x10 sup 1 sup 5 cm sup ...

  16. Design optimization of Pixel Structure for α-Si based uncooled Infrared detector

    Directory of Open Access Journals (Sweden)

    Sudha Gupta

    2013-12-01

    Full Text Available In this paper authors present the design and simulation results achieved for pixel structure of amorphous Si (α-Si based bolometer array. Most uncooled IR detectors in the world are based on VOx material. But this is not a standard material in IC technology and has many inherent disadvantages. The α-Si, an alternative material with high TCR is becoming as popular. However, large TCR values, in this material are achieved only in films of high resistivity. To achieve TCR value more than 2.5%/K, α-Si film resistivity is ~ 80 ohms-cm. This gives rise to very large pixel resistance of the order of 100 Mega ohms depending upon the design of the leg structure. This high pixel resistance causes very large noise and hence lower sensitivity. If leg width or membrane thickness is increased in order to reduce the pixel resistance, then this results in higher thermal conductance which also decreases sensitivity. To overcome this problem, pixel structure is so designed that within a pixel, only part of the electrical conduction is through α-Si and rest is through metal. Simulation using Coventorware software has been done to optimize pixel resistance as well as thermal conductance through legs so that maximum sensitivity could be obtained. Optimization is also carried out in order to reduce sensitivity of pixel resistance to variation in material resistivity.Defence Science Journal, 2013, 63(6, pp.581-588, DOI:http://dx.doi.org/10.14429/dsj.63.5758

  17. Spatial solitons in biased photovoltaic photorefractive materials with the pyroelectric effect

    Science.gov (United States)

    Katti, Aavishkar; Yadav, R. A.

    2017-01-01

    Spatial solitons in biased photorefractive media due to the photovoltaic effect and the pyroelectric effect are investigated. The pyroelectric field considered is induced due to the heating by the incident beam's energy. These solitons can be called screening photovoltaic pyroelectric solitons. It is shown that the solitons can exist in the bright and dark realizations. The conditions for formation of these solitons are discussed. Relevant example is considered to illustrate the self trapping of such solitons. The external electric field interacts with the photovoltaic field and the pyroelectric field to either support or oppose the self trapping.

  18. Real-time assessment of a linear pyroelectric sensor array for object classication

    Science.gov (United States)

    White, William E., III; Brown, Jeremy B.; Chari, Srikant; Jacobs, Eddie L.

    2010-10-01

    Pyroelectric linear arrays can be used to generate profiles of targets. Simulations have shown that generated profiles can be used to classify human and animal targets. A pyroelectric array system was used to collect data and classify targets as either human or non-human in real time. The pyroelectric array system consists of a 128-element Dias 128LTI pyroelectric linear array, an F/0.86 germanium lens, and an 18F4550 pic microcontroller for A/D conversion and communication. The classifier used for object recognition was trained using data collected in petting zoos and tested using data collected at the US-Mexico border in Arizona.

  19. Passivation Effect of Atomic Layer Deposition of Al2O3 Film on HgCdTe Infrared Detectors

    Science.gov (United States)

    Zhang, Peng; Ye, Zhen-Hua; Sun, Chang-Hong; Chen, Yi-Yu; Zhang, Tian-Ning; Chen, Xin; Lin, Chun; Ding, Ring-Jun; He, Li

    2016-09-01

    The passivation effect of atomic layer deposition of (ALD) Al2O3 film on a HgCdTe infrared detector was investigated in this work. The passivation effect of Al2O3 film was evaluated by measuring the minority carrier lifetime, capacitance versus voltage ( C- V) characteristics of metal-insulator-semiconductor devices, and resistance versus voltage ( R- V) characteristics of variable-area photodiodes. The minority carrier lifetime, C- V characteristics, and R- V characteristics of HgCdTe devices passivated by ALD Al2O3 film was comparable to those of HgCdTe devices passivated by e-beam evaporation of ZnS/CdTe film. However, the baking stability of devices passivated by Al2O3 film is inferior to that of devices passivated by ZnS/CdTe film. In future work, by optimizing the ALD Al2O3 film growing process and annealing conditions, it may be feasible to achieve both excellent electrical properties and good baking stability.

  20. APDs as Single-Photon Detectors for Visible and Near-Infrared Wavelenghts down to Hz Rates

    CERN Document Server

    Jöhren, R; Buglak, W; Hampf, D; Hannen, V; Mader, J; Nörtershäuser, W; Sánchez, R; Weinheimer, C

    2011-01-01

    For the SPECTRAP experiment at GSI, Germany, detectors with Single-Photon counting capability in the visible and near-infrared regime are required. For the wavelength region up to 1100 nm we investigate the performance of 2x2 mm^2 avalanche photo diodes (APDs) of type S0223 manufactured by Radiation Monitoring Devices. To minimize thermal noise, the APDs are cooled to approximately -170 deg. C using liquid nitrogen. By operating the diodes close to the breakdown voltage it is possible to achieve gains in excess of 2x10^4. Extremly low noise preamplifiers are used to read out the devices. The measurements presented in this paper have been obtained at a gain of 22,000. At a discriminator threshold of 6 mV the resulting dark count rate is in the region of 200/s. With these settings the studied APDs are able to detect single photons at 628 nm wavelength with a photodetection efficiency of (67+-7)%. Measurements at 1020 nm wavelength have been performed using the attenuated output of a grating spectrograph with a ...

  1. Fabrication of a ZnO Pyroelectric Sensor

    Directory of Open Access Journals (Sweden)

    Yuh-Chung Hu

    2008-01-01

    Full Text Available This paper proposes a two-step radio frequency (RF sputtering process to forma ZnO film for pyroelectric sensors. It is shown that the two-step sputtering process with alower power step followed by a higher power step can significantly improve the voltageresponsivity of the ZnO pyroelectric sensor. The improvement is attributed mainly to theformation of ZnO film with a strongly preferred orientation towards the c-axis.Furthermore, a nickel film deposited onto the uncovered parts of the ZnO film caneffectively improve the voltage responsivity at higher modulating frequencies since thenickel film can enhance the incident energy absorption of the ZnO layer.

  2. A virtual experiment on pyroelectric X-ray generator

    Energy Technology Data Exchange (ETDEWEB)

    Nasseri, Mohammad Mehdi, E-mail: mnasseri@aeoi.org.ir

    2015-09-01

    The production of pyroelectric type X-ray generators has a long term background. In case of using X-ray generators containing two pyroelectric crystals, some parameters have not been practically measured yet. This article aims to calculate such parameters by means of Geant4 Mont Carlo codes. The obtained edge energy of initial electrons was 3 keV at a constant pressure of 1mTorr and electric field of 250 kV/cm. The amplification coefficient production of electrons was increased reaching to a constant value of 2.7. The observed mean energy of produced gas ions was approximately 39 eV, equivalent to 5.7% of the emitted electrons. The efficiency of the generated X-ray was about 63% and did not show a considerable change as the energy of initial electrons increased.

  3. Mid-infrared Laser-Induced Fluorescence with Nanosecond Time Resolution Using a Superconducting Nanowire Single-Photon Detector: New Technology for Molecular Science.

    Science.gov (United States)

    Chen, Li; Schwarzer, Dirk; Verma, Varun B; Stevens, Martin J; Marsili, Francesco; Mirin, Richard P; Nam, Sae Woo; Wodtke, Alec M

    2017-06-20

    In contrast to UV photomultiplier tubes that are widely used in physical chemistry, mid-infrared detectors are notorious for poor sensitivity and slow time response. This helps explain why, despite the importance of infrared spectroscopy in molecular science, mid-infrared fluorescence is not more widely used. In recent years, several new technologies have been developed that open new experimental possibilities for research in the mid-infrared. In this Account, we present one of the more promising technologies, superconducting nanowire single photon detectors (SNSPDs) by sharing our experience with its use in a typical experiment carried out by physical chemists (laser-induced fluorescence) and comparing the SNSPD to a detector commonly used by physical chemists (InSb at LN Temperature). SNSPDs are fabricated from a thin film of superconducting metal, patterned into a meandering nanowire. The nanowire is cooled below its superconducting temperature, Tc, and held in a constant current circuit below the critical current necessary to destroy superconductivity, Ic. Upon absorption of a photon, the resulting heat is sufficient to destroy superconductivity across the entire width of the nanowire, an event that can be detected as a voltage pulse. In contrast to semiconductor-based detectors, which have a long wavelength cutoff determined by the band gap, the SNSPD exhibits single-photon sensitivity across the entire mid-IR spectrum. As these devices have not been used extensively outside the field of light detection technology research, one important goal of this Account is to provide practical details for the implementation of these devices in a physical chemistry laboratory. We provide extensive Supporting Information describing what is needed. This includes information on a liquid nitrogen cooled monochromator, the optical collection system including mid-infrared fibers, as well as a closed-cycle cryogenic cooler that reaches 0.3 K. We demonstrate the advantages of

  4. Systems Analysis for Thermal Infrared ` THz Torch' Applications

    Science.gov (United States)

    Hu, Fangjing; Sun, Jingye; Brindley, Helen E.; Liang, Xiaoxin; Lucyszyn, Stepan

    2015-05-01

    The ` THz Torch' concept was recently introduced by the authors for providing secure wireless communications over short distances within the thermal infrared (10-100 THz). Unlike conventional systems, thermal infrared can exploit front-end thermodynamics with engineered blackbody radiation. For the first time, a detailed power link budget analysis is given for this new form of wireless link. The mathematical modeling of a short end-to-end link is provided, which integrates thermodynamics into conventional signal and noise power analysis. As expected from the Friis formula for noise, it is found that the noise contribution from the pyroelectric detector dominates intrinsic noise. From output signal and noise voltage measurements, experimental values for signal-to-noise ratio (SNR) are obtained and compared with calculated predictions. As with conventional communications systems, it is shown for the first time that the measured SNR and measured bit error rate found with this thermodynamics-based system resembles classical empirical models. Our system analysis can serve as an invaluable tool for the development of thermal infrared systems, accurately characterizing each individual channel and, thus, enables the performance of multi-channel ` THz Torch' systems to be optimized.

  5. 红外探测器工艺用器皿清洗方法研究%Research of utensils cleaning for infrared detector process

    Institute of Scientific and Technical Information of China (English)

    孙浩; 宁提; 龚志红; 白雪飞; 王文燕

    2016-01-01

    红外探测器材料一般为窄带系材料,在其制备工艺过程中,杂质离子更容易导致缺陷能级或表面快态复合中心,需选取较优的器皿清洗方法,对工艺用器皿所含金属离子进行评测控制。本文通过电感耦合等离子体质谱仪对比碲镉汞红外探测器工艺线上不同的器皿及清洗方法,对清洗后金属离子残留测试分析,获得较佳的器皿清洗方法,更好地保证红外探测器制备后性能。%Many utensils are often used in infrared detector process,but metallic ions in utensils have great effect on the performance of infrared detector,so the superior utensil cleaning methods are selected to remove metallic ions in utensils.The residual metallic ions in utensils with different cleaning methods were measured and analyzed by ICP -MS,and the optimal cleaning method was obtained.This cleaning method is suitable for the different preparation technologies of infrared detector.

  6. Feasibility study of thermal energy harvesting using lead free pyroelectrics

    Science.gov (United States)

    Karim, Hasanul; Sarker, Md Rashedul H.; Shahriar, Shaimum; Arif Ishtiaque Shuvo, Mohammad; Delfin, Diego; Hodges, Deidra; (Bill Tseng, Tzu-Liang; Roberson, David; Love, Norman; Lin, Yirong

    2016-05-01

    Energy harvesting has significant potential for applications in energizing wireless sensors and charging energy storage devices. To date, one of the most widely investigated materials for mechanical and thermal energy harvesting is lead zirconate titanate (PZT). However, lead has detrimental effects on the environment and on health. Hence, alternative materials are required for this purpose. In this paper, a lead free material, lithium niobate (LNB) is investigated as a potential material for pyroelectric energy harvesting. Although its theoretical pyroelectric properties are lower compared to PZT, it has better properties than other lead free alternatives such as ZnO. In addition, LNB has a high Curie temperature of about 1142 °C, which makes it applicable for high temperature energy harvesting, where other pyroelectric ceramics are not suitable. Herein, an energy harvesting and storage system composed of a single crystal LNB and a porous carbon-based super-capacitor was investigated. It is found that with controlled heating and cooling, a single wafer of LNB (75 mm diameter and 0.5 mm thickness) could generate 437.72 nW cm-3 of power and it could be used to charge a super-capacitor with a charging rate of 2.63 mV (h cm3)-1.

  7. A VDF/TrFE copolymer on silicon pyroelectric sensor: design considerations and experiments

    NARCIS (Netherlands)

    Setiadi, D.; Regtien, P.P.L.

    1995-01-01

    For an optimal design of a VDF/TrFE (vinylidene fluoride trifluoroethylene) copolymer-on-silicon pyroelectric sensor, the one-dimensional diffusion equation is solved for the pyroelectric multilayer structure. Output current and voltage of the sensor are calculated. Improvement of the sensor can be

  8. Pyroelectric effect and polarization instability in self-assembled diphenylalanine microtubes

    Science.gov (United States)

    Esin, A.; Baturin, I.; Nikitin, T.; Vasilev, S.; Salehli, F.; Shur, V. Ya.; Kholkin, A. L.

    2016-10-01

    The natural ability of peptides and proteins to self-assemble into elongated fibrils is associated with several neurogenerative diseases. Diphenylalanine (FF) tubular structures that have the same structural motif as in Aβ-amyloid peptide (involved in Alzheimer's disease) are shown to possess remarkable physical properties ranging from piezoelectricity to electrochemical activities. In this work, we also discover a significant pyroelectric activity and measure the temperature dependence of the pyroelectric coefficient in the temperature range of 20-100 °C. Pyroelectric activity decreases with temperature contrary to most ferroelectric materials and significant relaxation of pyrocurrent is observed on cooling after heating above 50 °C. This unusual behavior is assigned to the temperature-induced disorder of water molecules inside the nanochannels. Pyroelectric coefficient and current and voltage figures of merit are estimated and future applications of pyroelectric peptide nanostructures in biomedical applications are outlined.

  9. Neutron interrogation systems using pyroelectric crystals and methods of preparation thereof

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Vincent; Meyer, Glenn A.; Falabella, Steven; Guethlein, Gary; Rusnak, Brian; Sampayan, Stephen; Spadaccini, Christopher M.; Wang, Li-Fang; Harris, John; Morse, Jeff

    2017-08-01

    According to one embodiment, an apparatus includes a pyroelectric crystal, a deuterated or tritiated target, an ion source, and a common support coupled to the pyroelectric crystal, the deuterated or tritiated target, and the ion source. In another embodiment, a method includes producing a voltage of negative polarity on a surface of a deuterated or tritiated target in response to a temperature change of a pyroelectric crystal, pulsing a deuterium ion source to produce a deuterium ion beam, accelerating the deuterium ion beam to the deuterated or tritiated target to produce a neutron beam, and directing the ion beam onto the deuterated or tritiated target to make neutrons using a voltage of the pyroelectric crystal and/or an HGI surrounding the pyroelectric crystal. The directionality of the neutron beam is controlled by changing the accelerating voltage of the system. Other apparatuses and methods are presented as well.

  10. Temperature Field Analysis for PZT Pyroelectric Cells for Thermal Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Chi-Yuan Lee

    2011-11-01

    Full Text Available This paper proposes the idea of etching PZT to improve the temperature variation rate of a thicker PZT sheet in order to enhance the energy conversion efficiency when used as pyroelectric cells. A partially covered electrode was proven to display a higher output response than a fully covered electrode did. A mesh top electrode monitored the temperature variation rate and the electrode area. The mesh electrode width affected the distribution of the temperature variation rate in a thinner pyroelectric material. However, a pyroelectric cell with a thicker pyroelectric material was beneficial in generating electricity pyroelectrically. The PZT sheet was further etched to produce deeper cavities and a smaller electrode width to induce lateral temperature gradients on the sidewalls of cavities under homogeneous heat irradiation, enhancing the temperature variation rate.

  11. Long—Range Effects on the Pyroelectric Coefficient of Ferroelectric Superlattice

    Institute of Scientific and Technical Information of China (English)

    DONGWen; WUYin-Zhong; 等

    2002-01-01

    Long-range effects on the pyroelectric coefficient of a ferroelectric superlattice consisting of two different ferroelectric materials are investigated based on the transverse Ising model.The effects of the interfacial coupling and the thickness of one period on the pyroelectric coefficient of the ferroelectric superlattics are studied by taking into account the long-range interaction.It is found that with the increase of the strength of the long-range interaction,the pyroelectric coefficient decreases when the temperature is lower than the phase transition temperature;the mumber of the pyroelectric peaks decreases gradually and the phase transition temperature increases,It is also found that with the decrease of the interfacial coupling and the thickness of one period.the phase transition temperature and the number of the pyroelectric peaks decrease.

  12. Pyroelectric response in crystalline hafnium zirconium oxide (Hf1-xZrxO2) thin films

    Science.gov (United States)

    Smith, S. W.; Kitahara, A. R.; Rodriguez, M. A.; Henry, M. D.; Brumbach, M. T.; Ihlefeld, J. F.

    2017-02-01

    Pyroelectric coefficients were measured for 20 nm thick crystalline hafnium zirconium oxide (Hf1-xZrxO2) thin films across a composition range of 0 ≤ x ≤ 1. Pyroelectric currents were collected near room temperature under zero applied bias and a sinusoidal oscillating temperature profile to separate the influence of non-pyroelectric currents. The pyroelectric coefficient was observed to correlate with zirconium content, increased orthorhombic/tetragonal phase content, and maximum polarization response. The largest measured absolute value was 48 μCm-2 K-1 for a composition with x = 0.64, while no pyroelectric response was measured for compositions which displayed no remanent polarization (x = 0, 0.91, and 1).

  13. Infrared Detector Research

    Science.gov (United States)

    1976-08-01

    7n rtMT IC -)) .r i 11ON ,c- r < css ,- c.Cu7 At,! flut~C-. ,sp .’TICF SCOATT E IN3 ; "" IS tic srtr rT-’Cv TATION "r𔃾 ,- c I I7 ’ " ,,’-"it ! IY...larger the compositional variation within the solidified grain. The lattice constants for HgTe and CdTe are nearly the same allowing for large...composition slice is reached a pinkish core region begins to develop in the center of the slice. Its origin is not known although it may be CdTe rich

  14. 手性化合物S811的强热释效应及反铁电特性%Large Pyroelectric Effect and Anti-ferroelectric Properties of Chiral Compound S811

    Institute of Scientific and Technical Information of China (English)

    牛小玲; 刘卫国; 刘鹏

    2011-01-01

    用热释电流谱、介电温谱、电滞回线谱、差示扫描量热仪(DSC)、热台偏光显微镜(PLM)对手性化合物S811的电学性能及相变行为进行了研究.热释电流谱、介电温谱显示S811在相变附近具有强热释电电流,其最大热释电系数达到384nC/(cm2·K),介电常数在相变过程也发生了突变.电滞回线谱显示,在冷却过程依次出现了反铁电体-铁电体转变的双电滞回线和单电滞回线,揭示了S811作为热释电探测材料的应用潜力,拓展了其应用范围.%The electrical properties and phase transition behaviors of chiral compound S811 have been investigated by pyroelectric, dielectric, polarization spectroscopy, DSC and PLM at different temperatures. It is found that S811 appeared a large pyroelectric current peak and a sharp growth of dielectric constants near the phase transition temperature The maximum value of the pyroelectric coefficient p obtained is 384nC/(cm2 · K). In the cooling process, the sample presented the transition of anti-ferroelectric to ferroelectric phase. The outstanding pyroelectric performances of S811 make it possible as a novel pyroelectric detectors.

  15. Note: Portable rare-earth element analyzer using pyroelectric crystal

    Energy Technology Data Exchange (ETDEWEB)

    Imashuku, Susumu, E-mail: imashuku.susumu.2m@kyoto-u.ac.jp; Fuyuno, Naoto; Hanasaki, Kohei; Kawai, Jun [Department of Materials Science and Engineering, Kyoto University, Sakyo, Kyoto 606-8501 (Japan)

    2013-12-15

    We report a portable rare-earth element analyzer with a palm-top size chamber including the electron source of a pyroelectric crystal and the sample stage utilizing cathodoluminescence (CL) phenomenon. The portable rare-earth element analyzer utilizing CL phenomenon is the smallest reported so far. The portable rare-earth element analyzer detected the rare-earth elements Dy, Tb, Er, and Sm of ppm order in zircon, which were not detected by scanning electron microscopy-energy dispersive X-ray spectroscopy analysis. We also performed an elemental mapping of rare-earth elements by capturing a CL image using CCD camera.

  16. Development of Blocked-Impurity-Band-Type Ge Detectors Fabricated with the Surface-Activated Wafer Bonding Method for Far-Infrared Astronomy

    Science.gov (United States)

    Hanaoka, M.; Kaneda, H.; Oyabu, S.; Yamagishi, M.; Hattori, Y.; Ukai, S.; Shichi, K.; Wada, T.; Suzuki, T.; Watanabe, K.; Nagase, K.; Baba, S.; Kochi, C.

    2016-07-01

    We report the current status of the development of our new detectors for far-infrared (FIR) astronomy. We develop Blocked-Impurity-Band (BIB)-type Ge detectors to realize large-format compact arrays covering a wide FIR wavelength range up to 200 \\upmu m. We fabricated Ge junction devices of different physical parameters with a BIB-type structure, using the room temperature, surface-activated wafer bonding (SAB) method. We measured the absolute responsivity and the spectral response curve of each device at low temperatures, using an internal blackbody source in a cryostat and a Fourier transform spectrometer, respectively. The results show that the SAB Ge junction devices have significantly higher absolute responsivities and longer cut-off wavelengths of the spectral response than the conventional bulk Ge:Ga device. Based upon the results, we discuss the optimum parameters of SAB Ge junction devices for FIR detectors. We conclude that SAB Ge junction devices possess a promising applicability to next-generation FIR detectors covering wavelengths up to ˜ 200 \\upmu m with high responsivity. As a next step, we plan to fabricate a BIB-type Ge array device in combination with a low-power cryogenic readout integrated circuit.

  17. Combination of temporal phase unwrapping and long-wave infrared digital holographic interferometry for metrology of mosaic detector under space simulated conditions

    Science.gov (United States)

    Vandenrijt, Jean-François; Thizy, Cédric; Beaumont, Florent; Garcia, José; Martin, Laurent; Fabron, Christophe; Prieto, Eric; Maciaszek, Thierry; Georges, Marc P.

    2015-08-01

    We present digital holographic interferometry (DHI) in the long-wave infrared for monitoring the deformation under cryogenic conditions of a segmented focal plane array to be used in a space mission. The long wavelength was chosen for its ability to allow measurement of displacements 20 times larger than DHI in the visible and which were foreseen with the test object under such temperature changes. The specimen consists of 4x4 mosaic of detectors assembled on a frame. It was required to assess the global deformation of the ensemble, the deformation of each detector, and piston movements of each of them with respect to their neighbors. For that reason we incorporated the temporal phase unwrapping by capturing a sufficiently high number of holograms between which the phase does not suffer strong variations. At last since the specimen exhibit specular reflectivity at that wavelength, it is illuminated through a reflective diffuser.

  18. Research on Spatial Uniformity Calibration of Pyroelectric Laser Energy Meter%热释电型激光能量计空间均匀性校准技术研究

    Institute of Scientific and Technical Information of China (English)

    易瑔; 罗天峰; 杨建昌

    2016-01-01

    热释电探测器由于其灵敏度高、响应速度快、体积小、损伤阈值高等特点,作为激光能量计的传感器在激光能量检测方面使用广泛。由于制作工艺的限制,热释电型激光能量计的热敏面灵敏度系数存在空间非均匀性问题,导致当激光照射到探测器不同位置时,激光能量测量结果不准确。针对这一问题,设计一种热释电型激光能量计空间均匀性校准方法,通过对热释电探头光路的控制,消除空间均匀性对测量结果的影响,并通过实例验证了方法的可行性。%For good features such as high sensitivity, fast response speed, small volume and high damage threshold, the pyroelectric detector as the sensor of the laser energy meter is widely used in laser energy detection. Limited by the manufacture process, the thermal surface sensitivity coefficients of the pyroelectric laser energy me⁃ter has spatial non-uniformity problem. When the laser irradiates the different positions of the detector, the results of the laser energy measurement is different. To solve this problem, a pyroelectric laser energy meter spatial uniformity calibration method is designed. Through controlling the light path of the pyroelectric detector, the influence on mea⁃sured results from spatial uniformity is removed. And the feasibility of the method is verified by the experiments.

  19. Development of a portable mid-infrared methane detection device

    Science.gov (United States)

    Liu, Hui-fang; He, Qi-xin; Zheng, Chuan-tao; Wang, Yi-ding

    2017-03-01

    Based on direct absorption spectroscopy (DAS), a portable methane (CH4) detection device was implemented. The device mainly includes a dual-channel non-dispersive infrared sensor (integrated with an infrared light source, light path and pyroelectric detector), a driving circuit of the sensor, an ARM11 embedded WinCE system, and a LabVIEW-based data-processing platform. Experiments were carried out with prepared CH4 samples to investigate the sensing performance. The relative detection error is less than 9.14% within the measuring range of 0—7×10-2. For a CH4 sample with concentration of 0 (i.e., pure nitrogen), the measured concentration fluctuation range is -1.2×10-5—+2×10-5. An Allan deviation analysis on the gas sample with concentration of 0 indicates that the 1 σ limit of detection ( LoD) of the device is 4.8×10-6 with an average time of 1 s. Experiments were performed on three CH4 samples with different concentrations to test the response time, which is validated to be less than 20 s. Due to the small size of the ARM11 embedded system and the powerful data processing capability of the LabVIEW platform, the proposed portable and miniaturized CH4 sensor shows a good application prospect in mining operations and some other industrial fields.

  20. Determinación del coeficiente piroeléctrico del sistema ferroeléctrico cerámico de Pb0.88Ln0.08Ti0.98Mn0.02O3 (Ln=La, Sm, Eu y su aplicación en detectores de infrarrojo

    Directory of Open Access Journals (Sweden)

    Suaste-Gómez, E.

    2004-12-01

    Full Text Available In this work the dielectric and pyroelectric characteristics of the ferroelectric ceramic system of Pb0.88(Ln0.08Ti0.98Mn0.02O3 (Ln = La, Sm, Eu are studied in order to determine its usefulness as infrared dectectors. Dielectric constant and pyroelectric coefficient of the ceramics were determined. This material with perovskite structure presented a phase transition from tetragonal to cubic on the heating process, besides of presenting high values of dielectric constant. Values of figure of merit for infrared detection Rv=pi/εr were calculated. The results were compared with other materials used as infrared detectors.En este trabajo se estudian las características dieléctricas y piroeléctricas del sistema ferroléctrico cerámico de Pb0.88(Ln0.08Ti0.98 Mn0.02O3 (Ln = La, Sm, Eu para determinar su utilidad como detectores de infrarrojo. Se determinó la constante dieléctrica y el coeficiente piroeléctrico de las cerámicas. Este material con estructura de perovskita presentó una transición de fase tetragonal a cúbica en el proceso de calentamiento, además de presentar altos valores de la constante dieléctrica. Se obtuvieron valores de la figura de mérito para detección infrarroja Rv=pi/εr Los resultados se compararon con otros materiales usados como detectores de infrarrojo.

  1. Simulation of near-infrared photodiode detectors based onβ-FeSi2/4H-SiC heterojunctions

    Institute of Scientific and Technical Information of China (English)

    Pu Hong-Bin; He Xin; Quan Ru-Dai; Cao Lin; Chen Zhi-Ming

    2013-01-01

    In this paper,we propose a near-infrared p-type β-FeSi2/n-type 4H-SiC heterojunction photodetector with semiconducting silicide (β-FeSi2) as the active region for the first time.The optoelectronic characteristics of the photodetector are simulated using a commercial simulator at room temperature.The results show that the photodetector has a good rectifying character and a good response to near-infrared light.Interface states should be minimized to obtain a lower reverse leakage current.The response spectrum of the β-FeSi2/4H-SiC detector,which consists of a p-type/β-FeSi2 absorption layer with a doping concentration of 1 x 1015 cm-3 and a thickness of 2.5 μm,has a peak of 755 mA/W at 1.42 μm.The illumination of the SiC side obtains a higher responsivity than that of the β-FeSi2 side.The results illustrate that the/β-FeSi2/4H-SiC heterojunction can be used as a near-infrared photodetector compatible with near-infrared optically-activated SiC-based power switching devices.

  2. Infrared imaging of cotton fiber bundles using a focal plane array detector and a single reflectance accessory

    Science.gov (United States)

    Infrared imaging is gaining attention as a technique used in the examination of cotton fibers. This type of imaging combines spectral analysis with spatial resolution to create visual images that examine sample composition and distribution. Herein, we report the use of an infrared instrument equippe...

  3. Investigation on the pyroelectric property of polycrystalline GdMnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X. [Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084 (China); School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004 (China); Zhao, Y. G., E-mail: ygzhao@tsinghua.edu.cn [Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China); Cui, Y. F.; Ye, L. D.; Zhao, D. Y.; Li, P. S.; Wang, J. W.; Zhu, M. H.; Zhang, H. Y. [Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084 (China); Rao, G. H., E-mail: rgh@guet.edu.cn [School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004 (China)

    2014-02-10

    Pyroelectric property of orthorhomic GdMnO{sub 3} polycrystalline samples was investigated. Two pyrocurrent peaks were observed with the sharp one near 20 K and the broad one at around 120 K. The dependences of these two peaks on magnetic field, heating rate, and poling voltage were explored systematically. The sharp peak is related to the ferroelectric transition, while the behavior of the broad one corresponds to dipole reorientation. Some key pyroelectric features are proposed to separate the spin-induced ferroelectricity from other effects. This work is helpful for understanding the pyroelectric property of multiferroic materials.

  4. Improper Ferroelectricity in Stuffed Aluminate Sodalites for Pyroelectric Energy Harvesting

    Science.gov (United States)

    Maeda, Yusaku; Wakamatsu, Toru; Konishi, Ayako; Moriwake, Hiroki; Moriyoshi, Chikako; Kuroiwa, Yoshihiro; Tanabe, Kenji; Terasaki, Ichiro; Taniguchi, Hiroki

    2017-03-01

    In the present study, we demonstrate ferroelectricity in stuffed aluminate sodalites (Ca1 -xSrx)8[AlO2]12(WO4)2 (x ≤0.2 ) (C1 -xSxAW ). Pyroelectric measurements clarify switchable spontaneous polarization in polycrystalline C1 -xSxAW , whose polarization values are on the order of 10-2 μ C /cm2 at room temperature. A weak anomaly in the dielectric permittivity at temperatures near the ferroelectric transition temperature suggests improper ferroelectricity of C1 -xSxAW for all investigated values of x . A comprehensive study involving synchrotron x-ray powder diffraction measurements, molecular dynamics simulations, and first-principles calculations clarifies that the ferroelectric phase transition of C1 -xSxAW is driven by the freezing of the fluctuations of WO4 tetrahedra in the voids of an [AlO2]12 12 - framework. The voltage response and electromechanical coupling factor of C1 -xSxAW estimated from the present results indicate that this material exhibits excellent performance as a pyroelectric energy harvester, suggesting that aluminate sodalites exhibit great promise as a class of materials for highly efficient energy-harvesting devices.

  5. Thermal Energy Harvesting Using Pyroelectric and Piezoelectric Effect

    Science.gov (United States)

    Kang, Miwon; Yeatman, Eric M.

    2016-11-01

    This paper presents a prototype of a thermal energy harvesting mechanism using both pyroelectric and piezoelectric effect. Thermal energy is one of abundant energy sources from various processes. Waste heat from a chip on a circuit board of the electronic device involves temperature differences from a few degrees C to over 100 °C. Therefore, 95 °C of a heat reservoir was used in this study. A repetitive time-dependant temperature variation is applied by a linear sliding table. The influence of heat conditions was investigated, by changing velocity and frequency of this linear sliding table. This energy harvesting mechanism employs Lead Zirconate Titanate (PZT-5H), a bimetal beam and two neodymium magnets. The pyroelectric effect is caused by a time-dependent temperature variation, and the piezoelectric effect is caused by stress from deformation of the bimetal. A maximum power output 0.54 μW is obtained at an optimal condition when the load resistance is 610 kΩ.

  6. Infrared thermography

    CERN Document Server

    Meola, Carosena

    2012-01-01

    This e-book conveys information about basic IRT theory, infrared detectors, signal digitalization and applications of infrared thermography in many fields such as medicine, foodstuff conservation, fluid-dynamics, architecture, anthropology, condition monitoring, non destructive testing and evaluation of materials and structures.

  7. The ^{55}Fe X-ray Energy Response of Mercury Cadmium Telluride Near-Infrared Detector Arrays

    CERN Document Server

    Fox, Ori D; Wen, Yiting; Foltz, Roger D; Hill, Robert J; Kimble, Randy A; Malumuth, Eliot; Rauscher, Bernard J

    2009-01-01

    A technique involving ^{55}Fe X-rays provides a straightforward method to measure the response of a detector. The detector's response can lead directly to a calculation of the conversion gain (e^- ADU^{-1}), as well as aid detector design and performance studies. We calibrate the ^{55}Fe X-ray energy response and pair production energy of HgCdTe using 8 HST WFC3 1.7 \\micron flight grade detectors. The results show that each K$\\alpha$ X-ray generates 2273 \\pm 137 electrons, which corresponds to a pair-production energy of 2.61 \\pm 0.16 eV. The uncertainties are dominated by our knowledge of the conversion gain. In future studies, we plan to eliminate this uncertainty by directly measuring conversion gain at very low light levels.

  8. HgCdTe Infrared Avalanche Photodiode Single Photon Detector Arrays for the LIST and Other Decadal Missions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop a HgCdTe avalanche photodiode (APD)  SWIR/IR linear mode photon counting (LMPC) array detector system in support of the LIST lidar. Provide a new type...

  9. Long-Range Effects on the Pyroelectric Coefficient of Ferroelectric Superlattice

    Institute of Scientific and Technical Information of China (English)

    DONG Wen; YAO Dong-Lai; WU Yin-Zhong; LI Zhen-Ya

    2002-01-01

    Long-range effects on the pyroelectric coefficient of a ferroelectric superlattice consisting of two differentferroelectric materials are investigated based on the transverse Ising model. The effects of the interfacial coupling andthe thickness of one period on the pyroelectric coefficient of the ferroelectric superlattice are studied by taking intoaccount the long-range interaction. It is found that with the increase of the strength of the long-range interaction, thepyroelectric coefficient decreases when the temperature is lower than the phase transition temperature; the number ofthe pyroelectric peaks decreases gradually and the phase transition temperature increases. It is also found that with thedecrease of the interfacial coupling and the thickness of one period, the phase transition temperature and the number ofthe pyroelectric peaks decrease.

  10. The pyroelectric coefficient of free standing GaN grown by HVPE

    Science.gov (United States)

    Jachalke, Sven; Hofmann, Patrick; Leibiger, Gunnar; Habel, Frank S.; Mehner, Erik; Leisegang, Tilmann; Meyer, Dirk C.; Mikolajick, Thomas

    2016-10-01

    The present study reports on the temperature dependent pyroelectric coefficient of free-standing and strain-free gallium nitride (GaN) grown by hydride vapor phase epitaxy (HVPE). The Sharp-Garn method is applied to extract the pyroelectric coefficient from the electrical current response of the crystals subjected to a sinusoidal temperature excitation in a range of 0 °C to 160 °C. To avoid compensation of the pyroelectric response by an internal conductivity, insulating GaN crystals were used by applying C, Mn, and Fe doping during HVPE growth. The different pyroelectric coefficients observed at room temperature due to the doping correlate well with the change of the lattice parameter c. The obtained data are compared to previously published theoretical and experimental values of thin film GaN and discussed in terms of a strained lattice.

  11. Dielectric and pyroelectric properties of lead zirconate titanate/polyurethane composites

    Science.gov (United States)

    Lam, K. S.; Wong, Y. W.; Tai, L. S.; Poon, Y. M.; Shin, F. G.

    2004-10-01

    0-3 composite ranging between 0 and 3, of ferroelectric ceramic lead zirconate titanate (PZT) and thermoplastic elastomer polyurethane (PU) were fabricated. The pyroelectric and dielectric properties of the hot-pressed thin film samples of various PZT volume fractions were measured. The experimental dielectric permittivities and losses agreed reasonably well with the Bruggeman model. The room temperature pyroelectric coefficients of the composites were found to increase linearly with PZT volume fraction and substantially larger than expected. For example, for a composite with 30% PZT, its pyroelectric coefficient is about 90μC/m2K at room temperature, which is more than tenfold of a PZT/PVDF composite of the same ceramic volume fraction. We propose a model in which the electrical conductivity of the composite system is taken into consideration to explain the linear relationship and the extraordinarily large pyroelectric coefficients obtained.

  12. Longitudinal and transverse pyroelectric effects in a chiral ferroelectric liquid crystal

    Energy Technology Data Exchange (ETDEWEB)

    Yablonskii, S. V., E-mail: yablonskii2005@yandex.ru; Bondarchuk, V. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Soto-Bustamante, E. A.; Romero-Hasler, P. N. [Universidad de Chile (Chile); Ozaki, M. [Osaka University, Department of Electronic Engineering, Faculty of Engineering (Japan); Yoshino, K. [Shimane Institute for Industrial Technology (Japan)

    2015-04-15

    In this study, we compare the results of experimental investigations of longitudinal and transverse pyroelectric effects in a chiral ferroelectric crystal. In a transverse geometry, we studied freely suspended liquid-crystal films. In both geometries, samples exhibited bistability, demonstrating stable pyroelectric signals of different polarities at zero voltage. It is shown that a bistable cell based on a freely suspended film requires 40 times less energy expenditures as compared to the conventional sandwich-type cell.

  13. Controlling dielectric and pyroelectric properties of compositionally graded ferroelectric rods by an applied pressure

    Science.gov (United States)

    Zheng, Yue; Woo, C. H.; Wang, Biao

    2007-06-01

    The polarization, charge offset, dielectric, and pyroelectric properties of a compositionally graded ferroelectric rod inside a high-pressure polyethylene tube are studied using a thermodynamic model based on the Landau-Ginzburg-Devonshire formulation. The calculated distribution of the polarization in the rod is nonuniform, and the corresponding charge offset, dielectric, and pyroelectric properties vary according to the applied pressure. This behavior may be used as a convenient means to control these properties for design optimization.

  14. High-efficiency WSi superconducting nanowire single-photon detectors for quantum state engineering in the near infrared

    CERN Document Server

    Jeannic, H Le; Cavaillès, A; Marsili, F; Shaw, M D; Huang, K; Morin, O; Nam, S W; Laurat, J

    2016-01-01

    We report on high-efficiency superconducting nanowire single-photon detectors based on amorphous WSi and optimized at 1064 nm. At an operating temperature of 1.8 K, we demonstrated a 93% system detection efficiency at this wavelength with a dark noise of a few counts per second. Combined with cavity-enhanced spontaneous parametric down-conversion, this fiber-coupled detector enabled us to generate narrowband single photons with a heralding efficiency greater than 90% and a high spectral brightness of $0.6\\times10^4$ photons/(s$\\cdot$mW$\\cdot$MHz). Beyond single-photon generation at large rate, such high-efficiency detectors open the path to efficient multiple-photon heralding and complex quantum state engineering.

  15. Photothermally Activated Pyroelectric Polymer Films for Harvesting of Solar Heat with a Hybrid Energy Cell Structure.

    Science.gov (United States)

    Park, Teahoon; Na, Jongbeom; Kim, Byeonggwan; Kim, Younghoon; Shin, Haijin; Kim, Eunkyoung

    2015-12-22

    Photothermal effects in poly(3,4-ethylenedioxythiophene)s (PEDOTs) were explored for pyroelectric conversion. A poled ferroelectric film was coated on both sides with PEDOT via solution casting polymerization of EDOT, to give highly conductive and effective photothermal thin films of PEDOT. The PEDOT films not only provided heat source upon light exposure but worked as electrodes for the output energy from the pyroelectric layer in an energy harvester hybridized with a thermoelectric layer. Compared to a bare thermoelectric system under NIR irradiation, the photothermal-pyro-thermoelectric device showed more than 6 times higher thermoelectric output with the additional pyroelectric output. The photothermally driven pyroelectric harvesting film provided a very fast electric output with a high voltage output (Vout) of 15 V. The pyroelectric effect was significant due to the transparent and high photothermal PEDOT film, which could also work as an electrode. A hybrid energy harvester was assembled to enhance photoconversion efficiency (PCE) of a solar cell with a thermoelectric device operated by the photothermally generated heat. The PCE was increased more than 20% under sunlight irradiation (AM 1.5G) utilizing the transmitted light through the photovoltaic cell as a heat source that was converted into pyroelectric and thermoelectric output simultaneously from the high photothermal PEDOT electrodes. Overall, this work provides a dynamic and static hybrid energy cell to harvest solar energy in full spectral range and thermal energy, to allow solar powered switching of an electrochromic display.

  16. Determination of surface electric charge profile in pyroelectric crystals

    Energy Technology Data Exchange (ETDEWEB)

    Ghaderi, R.; Davani, F. Abbasi, E-mail: fabbasi@sbu.ac.ir [Radiation Application Department, Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2014-12-08

    Pyroelectric crystals are used to produce high energy self-focused electron beams. Here, an experimental analysis in combination with simulation studies will be reported to investigate possible sources of this effect. In the experiments, the surface of crystal was divided into six separated parts and the rate of surface electric charge production was measured accordingly. A non-steady and spatially non-uniform distribution of the surface charge generation was observed, in which it tends to a uniform distribution in the course of experiment. The obtained surface electric charges from the experiments were used to simulate the electric field and potential around the crystal by COMSOL Multiphysics. It was observed that emitted electrons from the crystal surface were focused, and the non-uniformity in spatial charge is responsible for this phenomenon.

  17. Modeling of normal incidence absorption in p-type GaAs/AlGaAs quantum well infrared detectors

    Science.gov (United States)

    Brown, Gail J.; Szmulowicz, Frank

    1995-04-01

    The absorption of infrared radiation at normal incidence in p-type GaAs/AlGaAs quantum wells, unlike in n-type, is fundamentally allowed. We have measured and theoretically modeled the bound-to-continuum absorption in these p-type materials. The infrared absorption coefficient was calculated are based on the electronic structure, wave functions and optical matrix elements obtained from an 8 X 8 envelope-function approximation (EFA) calculation. The 8 X 8 EFA Hamiltonian incorporates the coupling between the heavy, light, spin-orbit, and conduction bands. In calculating the continuum states for bound-to- continuum intersubband absorption, we do not enclose the well in an artificial box with infinite walls. A comparison of the theoretical absorption and measured photoresponse results verified the accuracy of our model and provided a basis for optimizing the design of p-type quantum wells for infrared detection.

  18. Proton irradiation results for long-wave HgCdTe infrared detector arrays for Near-Earth Object Camera

    Science.gov (United States)

    Dorn, Meghan L.; Pipher, Judith L.; McMurtry, Craig; Hartman, Spencer; Mainzer, Amy; McKelvey, Mark; McMurray, Robert; Chevara, David; Rosser, Joshua

    2016-07-01

    HgCdTe detector arrays with a cutoff wavelength of ˜10 μm intended for the Near-Earth Object Camera (NEOCam) space mission were subjected to proton-beam irradiation at the University of California Davis Crocker Nuclear Laboratory. Three arrays were tested-one with 800-μm substrate intact, one with 30-μm substrate, and one completely substrate-removed. The CdZnTe substrate, on which the HgCdTe detector is grown, has been shown to produce luminescence in shorter wave HgCdTe arrays that causes an elevated signal in nonhit pixels when subjected to proton irradiation. This testing was conducted to ascertain whether or not full substrate removal is necessary. At the dark level of the dewar, we detect no luminescence in nonhit pixels during proton testing for both the substrate-removed detector array and the array with 30-μm substrate. The detector array with full 800-μm substrate exhibited substantial photocurrent for a flux of 103 protons/cm2 s at a beam energy of 18.1 MeV (˜750 e-/s) and 34.4 MeV (˜65 e-/s). For the integrated space-like ambient proton flux level measured by the Spitzer Space Telescope, the luminescence would be well below the NEOCam dark current requirement of <200 e-/s, but the pattern of luminescence could be problematic, possibly complicating calibration.

  19. Detector comparison for sulfur and chlorine detection with laser induced breakdown spectroscopy in the near-infrared-region

    Science.gov (United States)

    Weritz, F.; Schaurich, D.; Wilsch, G.

    2007-12-01

    Laser-induced breakdown spectroscopy has been employed for the investigation of the sulfur and chlorine content of building materials. Both, chloride and sulfate ions are major damaging species affecting the stability and lifetime of a structure. Chlorine and sulfur are mostly detected in the VUV and the NIR. In case of building materials the main elements like calcium or iron have many strong spectral lines over the whole spectral range, so that trace elements can only be detected in spectral windows unaffected from these lines. With regard to a preferably simply, robust against dust and vibrations and portable setup only the NIR spectral features are used for civil engineering applications. Most detectors, mainly CCD cameras have rapidly decreasing quantum efficiency in the NIR. Also the quantum efficiency of the photocathode of CCD-Detectors with image intensifier is decreasing in the NIR. Different CCD-detectors were tested with respect to high quantum efficiency and high dynamic range, which is necessary for simultaneous detection of weak spectral lines from trace elements and intense spectral lines from main elements. The measurements are made on reference samples consisting of cement, hydrated cement, cement mortar and concrete with well-defined amounts of the trace elements. Experimental conditions are chosen for an optimum intensity of the trace element spectral lines. The detector systems are compared by limit of detections and the signal to noise ratio.

  20. Infrared technology and applications

    Energy Technology Data Exchange (ETDEWEB)

    Lettington, A.H. (Royal Signals and Radar Establishment, Malvern (United Kingdom))

    1990-01-01

    This book is covered by the following topics: innovations in industrial infrared spectroscopy, detectors, advances in applied thermography, optical manufacturing techniques, optical design and testing.

  1. Quaternary Narrow-Band Semiconductors (HgTe)x(InSb)1-X for Far-Infrared Detectors.

    Science.gov (United States)

    1986-08-31

    Vapor Growth and Epitaxy. Coronado, California, 1981, p. 331. rn21. M. Rodot. Les Materiaux Semiconducteurs. Dunod, Paris, 1965. 22. E. M. Barrall ...Thermochim. Acta, 5, 377 (1973). 23. M. F. Kimmitt, G. C. Lopez , J. C. Giles, M. Takai, H. P. Roser, B. T. McGuckin and A. Black. Infrared Phys., 25, 767

  2. Fourier transform infrared spectroscopy with a sample deposition interface as a quantitative detector in size-exclusion chromatography

    NARCIS (Netherlands)

    Kok, S.J.; Arentsen, N.C.; Cools, P.J.C.H.; Hankemeier, Th.; Schoenmakers, P.J.

    2002-01-01

    The use of a state-of-the-art commercial solvent-elimination interface for liquid chromatography-infrared spectroscopy is discussed from the perspective of quantitative analysis. The effect of eluent flow-rate is investigated with respect to the homogeneity of the deposit and the trace width along t

  3. Theoretical investigation of InAs/GaSb type-II pin superlattice infrared detector in the mid wavelength infrared range

    Science.gov (United States)

    Kaya, U.; Hostut, M.; Kilic, A.; Sakiroglu, S.; Sokmen, I.; Ergun, Y.; Aydinli, A.

    2013-02-01

    In this study, we present the theoretical investigation of type-II InAs/GaSb superlattice p-i-n detector. Kronig-Penney and envelope function approximation is used to calculate band gap energy and superlattice minibands. Variational method is also used to calculate exciton binding energies. Our results show that carriers overlap increases at GaSb/InAs interface on the higher energy side while it decreases at InAs/GaSb interface on the lower energy side with increasing reverse bias due to shifting the hole wavefunction toward to the GaSb/InAs interface decisively. Binding energies increase with increasing electric field due to overall overlap of electron and hole wave functions at the both interfaces in contrast with type I superlattices. This predicts that optical absorption is enhanced with increasing electric field.

  4. A Novel Solid State Non-Dispersive Infrared CO2 Gas Sensor Compatible with Wireless and Portable Deployment

    Directory of Open Access Journals (Sweden)

    Desmond Gibson

    2013-05-01

    Full Text Available This paper describes development of a novel mid-infrared light emitting diode (LED and photodiode (PD light source/detector combination and use within a non-dispersive infrared (NDIR carbon dioxide gas sensor. The LED/PD based NDIR sensor provides fast stabilisation time (time required to turn on the sensor from cold, warm up, take and report a measurement, and power down again ≈1 second, longevity (>15 years, low power consumption and low cost. Described performance is compatible with “fit and forget” wireless deployed sensors in applications such as indoor air quality monitoring/control & energy conservation in buildings, transport systems, horticultural greenhouses and portable deployment for safety, industrial and medical applications. Fast stabilisation time, low intrinsic power consumption and cycled operation offer typical energy consumption per measurement of mJ’s, providing extended operation using battery and/or energy harvesting strategies (measurement interval of ≈ 2 minutes provides >10 years operation from one AA battery. Specific performance data is provided in relation to measurement accuracy and noise, temperature performance, cross sensitivity, measurement range (two pathlength variants are described covering ambient through to 100% gas concentration, comparison with NDIR utilizing thermal source/pyroelectric light source/detector combination and compatibility with energy harvesting. Semiconductor based LED/PD processing together with injection moulded reflective optics and simple assembly provide a route to low cost high volume manufacturing.

  5. A novel solid state non-dispersive infrared CO2 gas sensor compatible with wireless and portable deployment.

    Science.gov (United States)

    Gibson, Desmond; MacGregor, Calum

    2013-05-29

    This paper describes development of a novel mid-infrared light emitting diode (LED) and photodiode (PD) light source/detector combination and use within a non-dispersive infrared (NDIR) carbon dioxide gas sensor. The LED/PD based NDIR sensor provides fast stabilisation time (time required to turn on the sensor from cold, warm up, take and report a measurement, and power down again ≈1 second), longevity (>15 years), low power consumption and low cost. Described performance is compatible with "fit and forget" wireless deployed sensors in applications such as indoor air quality monitoring/control & energy conservation in buildings, transport systems, horticultural greenhouses and portable deployment for safety, industrial and medical applications. Fast stabilisation time, low intrinsic power consumption and cycled operation offer typical energy consumption per measurement of mJ's, providing extended operation using battery and/or energy harvesting strategies (measurement interval of ≈ 2 minutes provides >10 years operation from one AA battery). Specific performance data is provided in relation to measurement accuracy and noise, temperature performance, cross sensitivity, measurement range (two pathlength variants are described covering ambient through to 100% gas concentration), comparison with NDIR utilizing thermal source/pyroelectric light source/detector combination and compatibility with energy harvesting. Semiconductor based LED/PD processing together with injection moulded reflective optics and simple assembly provide a route to low cost high volume manufacturing.

  6. Fabrication of an Absorber-Coupled MKID Detector and Readout for Sub-Millimeter and Far-Infrared Astronomy

    Science.gov (United States)

    Brown, Ari-David; Hsieh, Wen-Ting; Moseley, S. Harvey; Stevenson, Thomas R.; U-yen, Kongpop; Wollack, Edward J.

    2010-01-01

    We have fabricated absorber-coupled microwave kinetic inductance detector (MKID) arrays for sub-millimeter and farinfrared astronomy. Each detector array is comprised of lambda/2 stepped impedance resonators, a 1.5µm thick silicon membrane, and 380µm thick silicon walls. The resonators consist of parallel plate aluminum transmission lines coupled to low impedance Nb microstrip traces of variable length, which set the resonant frequency of each resonator. This allows for multiplexed microwave readout and, consequently, good spatial discrimination between pixels in the array. The Al transmission lines simultaneously act to absorb optical power and are designed to have a surface impedance and filling fraction so as to match the impedance of free space. Our novel fabrication techniques demonstrate high fabrication yield of MKID arrays on large single crystal membranes and sub-micron front-to-back alignment of the microstrip circuit.

  7. Structural and electrical properties of InAs/GaSb superlattices grown by metalorganic vapor phase epitaxy for midwavelength infrared detectors

    Energy Technology Data Exchange (ETDEWEB)

    Arikata, Suguru; Kyono, Takashi [Semiconductor Technologies Laboratory, Sumitomo Electric Industries, LTD., Hyogo (Japan); Miura, Kouhei; Balasekaran, Sundararajan; Inada, Hiroshi; Iguchi, Yasuhiro [Transmission Devices Laboratory, Sumitomo Electric Industries, LTD., Yokohama (Japan); Sakai, Michito [Sensor System Research Group, Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki (Japan); Katayama, Haruyoshi [Space Technology Directorate I, Japan Aerospace Exploration Agency (JAXA), Tsukuba, Ibaraki (Japan); Kimata, Masafumi [College of Science and Engineering, Ritsumeikan University, Shiga (Japan); Akita, Katsushi [Sumiden Semiconductor Materials, LTD., Hyogo (Japan)

    2017-03-15

    InAs/GaSb superlattice (SL) structures were fabricated on GaSb substrates by metalorganic vapor phase epitaxy (MOVPE) toward midwavelength infrared (MWIR) photodiodes. Almost defect-free 200-period SLs with a strain-compensation interfacial layer were successfully fabricated and demonstrate an intense photoluminescence peak centered at 6.1 μm at 4 K and an external quantum efficiency of 31% at 3.5 μm at 20 K. These results indicate that the high-performance MWIR detectors can be fabricated in application with the InAs/GaSb SLs grown by MOVPE as an attractive method for production. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Theoretical prediction of the source-detector separation distance suited to the application of the spatially resolved spectroscopy from the near-infrared attenuation data cube of tissues

    CERN Document Server

    Ri, Yong-Wu; Im, Song-Jin

    2014-01-01

    The modified Beer-Lambert law (MBL) and the spatially resolved spectroscopy are used to measure the tissue oxidation in muscles and brains by the continuous wave near-infrared spectroscopy. The spatially resolved spectroscopy predicts the change in the concentration of the absorber by measuring the slope of attenuation data according to the separation and calculating the absorption coefficients of tissue on the basis of the slop in attenuation at the separation distance satisfying the linearity of this slop. This study analyzed the appropriate source-detector separation distance by using the diffuse approximation resolution for photon migration when predicting the absorption coefficient by the spatially resolved spectroscopy on the basis of the reflective image of the tissue. We imagine the 3 dimensional attenuation image with the absorption coefficient, reduced scattering coefficient and separation distance as its axes and obtained the attenuation data cube by calculating the attenuation on a certain interva...

  9. Evaluation of HgCdTe on GaAs Grown by Molecular Beam Epitaxy for High-Operating-Temperature Infrared Detector Applications

    Science.gov (United States)

    Wenisch, J.; Schirmacher, W.; Wollrab, R.; Eich, D.; Hanna, S.; Breiter, R.; Lutz, H.; Figgemeier, H.

    2015-09-01

    Molecular beam epitaxy (MBE) growth of HgCdTe (MCT) on alternative substrates enables production of both cheaper and more versatile (third-generation) infrared (IR) detectors. After rapid progress in the development of MBE-grown MCT on GaAs in recent years, the question of whether the considerable benefits of this material system are also applicable to high-operating-temperature (HOT) applications demands attention. In this paper, we present a mid-wavelength-IR 640 × 512 pixel, 15- μm-pitch focal-plane array with operability of 99.71% at operating temperature of 120 K and low dark current density. In the second part of the paper, MBE growth of short-wavelength IR material with Cd fraction of up to 0.8 is investigated as the basis for future evaluation of the material for low-light-level imaging HOT applications.

  10. Toward absolute chemical composition distribution measurement of polyolefins by high-temperature liquid chromatography hyphenated with infrared absorbance and light scattering detectors.

    Science.gov (United States)

    Lee, Dean; Shan, Colin Li Pi; Meunier, David M; Lyons, John W; Cong, Rongjuan; deGroot, A Willem

    2014-09-02

    Chemical composition distribution (CCD) is a fundamental metric for representing molecular structures of copolymers in addition to molecular weight distribution (MWD). Solvent gradient interaction chromatography (SGIC) is commonly used to separate copolymers by chemical composition in order to obtain CCD. The separation of polymer in SGIC is, however, not only affected by chemical composition but also by molecular weight and architecture. The ability to measure composition and MW simultaneously after separation would be beneficial for understanding the impact of different factors and deriving true CCD. In this study, comprehensive two-dimensional chromatography (2D) was coupled with infrared absorbance (IR5) and light scattering (LS) detectors for characterization of ethylene-propylene copolymers. Polymers were first separated by SGIC as the first dimension chromatography (D1). The separated fractions were then characterized by the second dimension (D2) size exclusion chromatography (SEC) with IR5 and LS detectors. The concentrations and compositions of the separated fractions were measured online using the IR5 detector. The MWs of the fractions were measured by the ratio of LS to IR5 signals. A metric was derived from online concentration and composition data to represent CCD breadth. The metric was shown to be independent of separation gradients for an "absolute" measurement of CCD breadth. By combining online composition and MW data, the relationship of MW as a function of chemical composition was obtained. This relationship was qualitatively consistent with the results by SEC coupled to IR5, which measures chemical composition as a function of logMW. The simultaneous measurements of composition and MW give the opportunity to study the SGIC separation mechanism and derive chain architectural characteristics of polymer chains.

  11. 红外线阵探测器盲元定位与补偿%Blind pixel detection and compensation for infrared linear detector

    Institute of Scientific and Technical Information of China (English)

    徐世伟; 魏东; 王大鹏; 刘万成

    2014-01-01

    为减少红外线列探测器的条纹噪声与非均匀性噪声受环境温度和探测器工作时间的影响,提出了一种处理盲元的综合算法。首先依据探测器最终数据输出来检测盲元通道;然后依据通道位置与数量调整偏移量值,并根据探测器的阵列结构特点,对480×6个像元完成精确的盲元定位;最后完成对含有盲元通道的非均匀校正。以FPGA处理模块为核心,完成了红外探测器实时采集与处理。图像校正效果良好,具有良好的实时性和可移植性。%An integrated algorithm dealing with blind pixel was proposed to reduce the stripe noise and non﹣uniformity noise of the infrared linear detector which affected by ambient temperature and its operation time. First, the bad pixel channel was detected based on the final output data of the detector, and then the offset value was adjusted based on the position and number of the bad pixel channel, and an accurate bad pixel positioning to 480×6 pixel was finished according to the structure characteristics of the detector array. Non﹣uniformity correction of the bad pixel channel was completed in the end. In this paper, FPGA processing module was taken as the core of the whole algorithm to complete the real﹣time acquisition and processing of infrared images. The test results show that the qualities of correction images are all very well, and the algorithm proposed in this paper has a good real﹣time performance and portability.

  12. Mid-infrared High Energy Laser Beam Detector Array%中红外激光光斑探测阵列

    Institute of Scientific and Technical Information of China (English)

    杨鹏翎; 冯国斌; 王振宝; 邵碧波; 张磊; 冯刚; 闫燕; 武俊杰; 王群书

    2011-01-01

    The energy and power density distributions at target are important parameters for high energy system performance evaluation. A high energy laser beam detector array is developed using photoelectric and calorimetric compound method to accurately measure large area and long pulse mid-infrared laser. The detector array consists of graphite calorimeter and PbSe photoelectric detector array, temperature and voltage amplifier, analog to digital converter and signal processor. The effective sensitive area of the system is 22 cmX22 cm, the spatial resolution is 2.2 cm, and the temporal resolution is 20 ms, with the total energy measurement uncertainty of less than 10% and the power density distribution measurement uncertainty of less than 15%. The system is very suitable for high energy and large area mid-infrared laser beam measurement.%到靶能量和光斑分布参数是评价高能激光系统性能指标的重要参数,为准确测量中红外高能激光系统远场能量和功率密度的时空分布,采用热吸收和光电探测相结合的测量方法,研制了可用于大面积、长脉冲中红外高能激光测量的复合式光斑探测阵列.探测阵列由石墨热吸收单元和PbSe光电探测器阵列、信号调理放大电路、数据采集单元和信号处理单元等几部分组成,有效测量面积为22 cm×22 cm,光斑测量空间分辨率为2.2 cm,时间分辨率为20 ms,能量测量不确定度小于10%,功率密度测量不确定度小于15%.采用该系统,可实现高能量、大面积中红外高能激光光斑参数的综合测量.

  13. A temperature oscillation instrument to determine pyroelectric properties of materials at low frequencies: Towards elimination of lock-in methods

    NARCIS (Netherlands)

    Khanbareh, H.; Schelen, J.B.J.; Van der Zwaag, S.; Groen, W.A.

    2015-01-01

    Pyroelectric properties of materials can be accurately determined by applying a new digital signal processing method on the discrete sampled data obtained with a temperature oscillation technique. The pyroelectric coefficient is calculated from the component of the generated current 90∘ out of phase

  14. Mechanism of the Pyroelectric Response under Direct-Current Bias in La-Modified Lead Zirconate Titanate Stannate Ceramics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-Ling; WANG Gen-Shui; CHEN Xue-Feng; CAO Fei; DONG Xian-Lin; GU Yan; HE Hong-Liang; LIU Yu-Sheng

    2011-01-01

    Dielectric and pyroelectric properties ofPbo.97Lao.o2(Zro.42Sno.4oTio.i8)03 ceramics are investigated as functions of temperature and dc bias field. Induced and intrinsic pyroelectric coefficients pind and p0 are calculated and analyzed. It is found that the sign, value and variation of the net pyroelectric coefficient p with increasing dc bias all are dominated by p0 under applied biases. Polarization and depolarization processes under dc biases are analyzed. Besides the contribution of pind, the diffuse and decreased pyroelectric response under dc bias compared with that of an identical Geld poled sample without dc bias is mainly attributed to the depolarization process under dc bias.%@@ Dielectric and pyroelectric properties of Pbo.s7Lao.o2(Zro.42Sno.4OTio.is)O3 ceramics are investigated as functions of temperature and do bias field.Induced and intrinsic pyroelectric coefficients pind and p0 are calculated and analyzed.It is found that the sign,value and variation of the net pyroelectric coefficient p with increasing dc bias all are dominated by p0 under applied biases.Polarization and depolarization processes under do biases are analyzed.Besides the contribution of pind,the diffuse and decreased pyroelectric response under do bias compared with that of an identical field poled sample without do bias is mainly attributed to the depolarization process under do bias.

  15. A temperature oscillation instrument to determine pyroelectric properties of materials at low frequencies: Towards elimination of lock-in methods.

    NARCIS (Netherlands)

    Khanbareh, H.; Schelen, J.B.J.; van der Zwaag, S.; Groen, W.A.

    2015-01-01

    Pyroelectric properties of materials can be accurately determined by applying a new digital signal processing method on the discrete sampled data obtained with a temperature oscillation technique. The pyroelectric coefficient is calculated from the component of the generated current 90(∘) out of pha

  16. High-frequency thermal-electrical cycles for pyroelectric energy conversion

    Energy Technology Data Exchange (ETDEWEB)

    Bhatia, Bikram [Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801 (United States); Damodaran, Anoop R. [Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801 (United States); Cho, Hanna [Department of Mechanical Engineering, Texas Tech University, Lubbock, Texas 79409 (United States); Martin, Lane W. [Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801 (United States); Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); King, William P., E-mail: wpk@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, Illinois 61801 (United States); Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2014-11-21

    We report thermal to electrical energy conversion from a 150 nm thick BaTiO{sub 3} film using pyroelectric cycles at 1 kHz. A microfabricated platform enables temperature and electric field control with temporal resolution near 1 μs. The rapid electric field changes as high as 11 × 10{sup 5 }kV/cm-s, and temperature change rates as high as 6 × 10{sup 5 }K/s allow exploration of pyroelectric cycles in a previously unexplored operating regime. We investigated the effect of phase difference between electric field and temperature cycles, and electric field and temperature change rates on the electrical energy generated from thermal-electrical cycles based on the pyroelectric Ericsson cycle. Complete thermodynamic cycles are possible up to the highest cycle rates tested here, and the energy density varies significantly with phase shifts between temperature and electric field waveforms. This work could facilitate the design and operation of pyroelectric cycles at high cycle rates, and aid in the design of new pyroelectric systems.

  17. Energy harvesting from pavements via PVDF: hybrid piezo-pyroelectric effects

    Science.gov (United States)

    Tao, Junliang; Hu, Jie; Wu, Guangxi

    2016-04-01

    In the U.S., there are over 4 million miles (6 million km) of roadways and more than 250 million registered vehicles. The energy lost in the pavement system due to traffic-induced vibration and deformation is enormous. If effectively harvested, such energy can serve as an alternative sustainable energy source that can be easily integrated to the transportation system. The potential of PVDF, which is a piezoelectric polymer material, is investigated as a potential energy harvester integrated in pavement systems. The uniqueness of this study lies in that the electrical response of PVDF under coupled mechanical and thermal stimulations are studied. It is well known that most piezoelectric materials are also pyroelectric materials, which convert temperature change into electricity. However, the potential of PVDF as a hybrid piezo-pyroelectric energy harvester has been seldom studied. Through series of well controlled experiments, it is found that there exists interesting coupling phenomenon between piezoelectric and pyroelectric effects of PVDF: the voltage generated by simultaneous mechanical and thermal stimulations is the sum of voltages generated by separate stimulations. In addition, an estimation of power generation through piezoelectric and pyroelectric effect is conducted. Finally, the overall effects of temperature on hybrid piezo-pyroelectric energy harvesting are discussed.

  18. Pyroelectric properties and electrocaloric effect in TGS1-xPx single crystals

    Science.gov (United States)

    Sampathkumar, P.; Srinivasan, K.

    2016-10-01

    Triglycine sulfate (TGS) single crystals modified with phosphoric acid (TGS1-xPx) have been grown by slow evaporation technique at room temperature. Lattice parameters were identified by using single crystal x-ray diffractometer. The dielectric, pyroelectric, ferroelectric properties and electrocaloric effect have been investigated. Curie temperature of grown crystals was determined from dielectric constant measurements at various temperatures at a frequency of 1 kHz. The Curie temperature is found decreased for the TGS single crystals with the addition of phosphoric acid. Room temperature P-E hysteresis loops of TGS1-xPx single crystals are presented. The values of coercive field Ec, spontaneous polarization Ps and internal bias field Eb were obtained from the hysteresis loops. Discussion on pyroelectric properties as a function of temperature and applied electric field is presented. Figure of merits (FOMs) were determined to study the pyroelectric performance of the grown crystals. Among all compositions of x, x = 0.2 (i.e., TGS0.8P0.2) single crystals exhibited the largest pyroelectric coefficient and pyroelectric figure of merit at room temperature. From the above investigations the electrocaloric temperature change, ΔT of TGS1-xPx single crystals at selected applied fields and temperatures are obtained by indirect method and discussed.

  19. Design of Low Power CMOS Read-Out with TDI Function for Infrared Linear Photodiode Array Detectors

    Science.gov (United States)

    Vizcaino, Paul; Ramirez-Angulo, Jaime; Patel, Umesh D.

    2007-01-01

    A new low voltage CMOS infrared readout circuit using the buffer-direct injection method is presented. It uses a single supply voltage of 1.8 volts and a bias current of 1uA. The time-delay integration technique is used to increase the signal to noise ratio. A current memory circuit with faulty diode detection is used to remove dark current for background compensation and to disable a photodiode in a cell if detected as faulty. Simulations are shown that verify the circuit that is currently in fabrication in 0.5ym CMOS technology.

  20. Characterization of Perovskite Films Grown by a Novel Low-Temperature Process for Uncooled IR Detector Applications

    Science.gov (United States)

    2008-12-01

    and semiconductor thin- films (Schwenzer et al., 2006; Kisailus et al, 2006; Brutchey and Morse, 2006). The resulting pyroelectric, perovskite -based...1 CHARACTERIZATION OF PEROVSKITE FILMS GROWN BY A NOVEL LOW- TEMPERATURE PROCESS FOR UNCOOLED IR DETECTOR APPLICATIONS W.L. Sarney* and J.W...multimetallic perovskite nanoparticle deposition, direct-write digitally-scripted laser phase conversion, and MEMS fabrication and optimization

  1. Non-Dispersive Infrared Sensor for Online Condition Monitoring of Gearbox Oil.

    Science.gov (United States)

    Rauscher, Markus S; Tremmel, Anton J; Schardt, Michael; Koch, Alexander W

    2017-02-18

    The condition of lubricating oil used in automotive and industrial gearboxes must be controlled in order to guarantee optimum performance and prevent damage to machinery parts. In normal practice, this is done by regular oil change intervals and routine laboratory analysis, both of which involve considerable operating costs. In this paper, we present a compact and robust optical sensor that can be installed in the lubrication circuit to provide quasi-continuous information about the condition of the oil. The measuring principle is based on non-dispersive infrared spectroscopy. The implemented sensor setup consists of an optical measurement cell, two thin-film infrared emitters, and two four-channel pyroelectric detectors equipped with optical bandpass filters. We present a method based on multivariate partial least squares regression to select appropriate optical bandpass filters for monitoring the oxidation, water content, and acid number of the oil. We perform a ray tracing analysis to analyze and correct the influence of the light path in the optical setup on the optical parameters of the bandpass filters. The measurement values acquired with the sensor for three different gearbox oil types show high correlation with laboratory reference data for the oxidation, water content, and acid number. The presented sensor can thus be a useful supplementary tool for the online condition monitoring of lubricants when integrated into a gearbox oil circuit.

  2. Non-Dispersive Infrared Sensor for Online Condition Monitoring of Gearbox Oil

    Directory of Open Access Journals (Sweden)

    Markus S. Rauscher

    2017-02-01

    Full Text Available The condition of lubricating oil used in automotive and industrial gearboxes must be controlled in order to guarantee optimum performance and prevent damage to machinery parts. In normal practice, this is done by regular oil change intervals and routine laboratory analysis, both of which involve considerable operating costs. In this paper, we present a compact and robust optical sensor that can be installed in the lubrication circuit to provide quasi-continuous information about the condition of the oil. The measuring principle is based on non-dispersive infrared spectroscopy. The implemented sensor setup consists of an optical measurement cell, two thin-film infrared emitters, and two four-channel pyroelectric detectors equipped with optical bandpass filters. We present a method based on multivariate partial least squares regression to select appropriate optical bandpass filters for monitoring the oxidation, water content, and acid number of the oil. We perform a ray tracing analysis to analyze and correct the influence of the light path in the optical setup on the optical parameters of the bandpass filters. The measurement values acquired with the sensor for three different gearbox oil types show high correlation with laboratory reference data for the oxidation, water content, and acid number. The presented sensor can thus be a useful supplementary tool for the online condition monitoring of lubricants when integrated into a gearbox oil circuit.

  3. Non-Dispersive Infrared Sensor for Online Condition Monitoring of Gearbox Oil

    Science.gov (United States)

    Rauscher, Markus S.; Tremmel, Anton J.; Schardt, Michael; Koch, Alexander W.

    2017-01-01

    The condition of lubricating oil used in automotive and industrial gearboxes must be controlled in order to guarantee optimum performance and prevent damage to machinery parts. In normal practice, this is done by regular oil change intervals and routine laboratory analysis, both of which involve considerable operating costs. In this paper, we present a compact and robust optical sensor that can be installed in the lubrication circuit to provide quasi-continuous information about the condition of the oil. The measuring principle is based on non-dispersive infrared spectroscopy. The implemented sensor setup consists of an optical measurement cell, two thin-film infrared emitters, and two four-channel pyroelectric detectors equipped with optical bandpass filters. We present a method based on multivariate partial least squares regression to select appropriate optical bandpass filters for monitoring the oxidation, water content, and acid number of the oil. We perform a ray tracing analysis to analyze and correct the influence of the light path in the optical setup on the optical parameters of the bandpass filters. The measurement values acquired with the sensor for three different gearbox oil types show high correlation with laboratory reference data for the oxidation, water content, and acid number. The presented sensor can thus be a useful supplementary tool for the online condition monitoring of lubricants when integrated into a gearbox oil circuit. PMID:28218701

  4. Numerical method to optimize the Polar-Azimuthal Orientation of Infrared Superconducting Nanowire Single-Photon Detectors

    CERN Document Server

    Csete, Mária; Najafi, Faraz; Hu, Xiaolong; Berggren, Karl K

    2011-01-01

    A novel finite-element method for calculating the illumination-dependence of absorption in three-dimensional nanostructures is presented based on the RF module of the COMSOL software package. This method is capable of numerically determining the optical response and near-field distribution of sub-wavelength periodic structures as a function of illumination orientations specified by polar angle, fi, and azimuthal angle, gamma. The method was applied to determine the illumination-angle-dependent absorptance in cavity-based superconducting-nanowire single-photon detector (SNSPD) designs. Niobium-nitride stripes based on dimensions of conventional SNSPDs and integrated with ~ quarter-wavelength hydrogensilsesquioxane-filled nano-optical cavities and covered by a thin gold film acting as a reflector were illuminated from below by p-polarized light in this study. The numerical results were compared to results from complementary transfer-matrix-method calculations on composite layers made of analogous film-stacks. T...

  5. Pyroelectric composite film for X-ray intensity detection

    Directory of Open Access Journals (Sweden)

    Walter Katsumi Sakamoto

    2012-04-01

    Full Text Available Composite material obtained with modified lead titanate (Pz34 ferroelectric ceramic and polyether-ether-ketone (PEEK polymer matrix was used as sensitive component to measure X-ray intensity in a novel detection system. The sensing element works as a thermal transducer, converting a non-quantified thermal flux into an output measurable quantity of electrical voltage. The samples were obtained up to 60 vol.% of ceramic, by hot pressing the mixture of Pz34 and PEEK powders at 368 °C and applying 12 MPa pressure for 2.0 hours. The sensor response varies from 2.70 to 0.80 V in the energy fluence rate range of 6.30 to 37.20 W.m-2. The absorbed incident energy was analyzed as a function of the ionizing energy. Furthermore, by measuring the pyroelectric activity of the composite film it was observed that there is no degradation of the sensor after the irradiation.

  6. Pyroelectric and dielectric properties of ferroelectric films with interposed dielectric buffer layers

    Science.gov (United States)

    Espinal, Y.; Kesim, M. T.; Misirlioglu, I. B.; Trolier-McKinstry, S.; Mantese, J. V.; Alpay, S. P.

    2014-12-01

    The dielectric and pyroelectric properties of c-domain ferroelectric films with linear dielectric buffer layers were investigated theoretically. Computations were carried out for multilayers consisting of PbZr0.2Ti0.8O3 with Al2O3, SiO2, Si3N4, HfO2, and TiO2 buffers on metalized Si. It is shown that the dielectric and pyroelectric properties of such multilayers can be increased by the presence of the buffer compared to ferroelectric monolayers. Calculations for PbZr0.2Ti0.8O3 films with 1% Al2O3 interposed between electrodes on Si show that the dielectric and pyroelectric coefficients are 310 and 0.070 μC cm-2 °C-1, respectively. Both values are higher than the intrinsic response of PbZr0.2Ti0.8O3 monolayer on Si.

  7. Layer thickness and period as design parameters to tailor pyroelectric properties in ferroelectric superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Misirlioglu, I. B., E-mail: burc@sabanciuniv.edu [Faculty of Engineering and Natural Sciences, Sabanci University, Tuzla/Orhanli, 34956 Istanbul (Turkey); Kesim, M. T. [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Alpay, S. P. [Department of Materials Science and Engineering and Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

    2014-10-27

    We theoretically examine the pyroelectric properties of ferroelectric-paraelectric superlattices as a function of layer thickness and configuration using non-linear thermodynamics coupled with electrostatic and electromechanical interactions between layers. We specifically study PbZr{sub 0.3}Ti{sub 0.7}O{sub 3}/SrTiO{sub 3} superlattices. The pyroelectric properties of such constructs consisting of relatively thin repeating units are shown to exceed the pyroelectric response of monolithic PbZr{sub 0.3}Ti{sub 0.7}O{sub 3} films. This is related to periodic internal electric fields generated due to the polarization mismatch between layers that allows tailoring of the shift in the transition temperature. Our results indicate that higher and electric field sensitive pyroresponse can be achieved from layer-by-layer engineered ferroelectric heterostructures.

  8. 红外甲烷气体浓度检测仪设计%Design of Infrared Methane Gas Concentration Detector

    Institute of Scientific and Technical Information of China (English)

    郭晓满; 戴景民

    2016-01-01

    Methane is the main components of the coal gas, the proportion of the gas explosion accident in the total of coal mine safety accidents has increasingly in recent years of our country. The methane gas detection under the mine becomes a faced important issue. This paper gives a brief interview of the frequently-used gas detection methods and uses infrared absorption detection theory combined modern detection equipment and data processing method, based on the STC12C5A60S2 processing system a portable methane gas concentration detector with audible and visual alarm function is designed. The detector has the advantage of small volume, fast response and stable performance, etc.%甲烷气体是煤矿瓦斯气体的主要成分,近年来我国因瓦斯爆炸而导致的事故占总煤矿安全事故的比重越来越大,这使得矿下甲烷气体的监测成为我们面临的重要问题。本文对于目前常用的气体浓度检测方法做了简要概述,利用红外吸收检测原理,结合现代检测设备和数据处理方法基于S T C12C5A60S2单片机处理系统,设计了一款便携式、有声光报警功能的甲烷气体浓度检测仪。该检测仪具有体积小、响应速度快、性能稳定等优点。

  9. Effective Pyroelectric Coefficient and Polarization Offset of Compositionally Step-like Graded Ferroelectric Structures

    Institute of Scientific and Technical Information of China (English)

    CAO Hai-Xia; WU Yin-Zhong; LI Zhen-Ya

    2005-01-01

    In this paper, the effective pyroelectric coefficient and polarization offset of the compositionally step-like graded multilayer ferroelectric structures have been studied by use of the first-principles approach. It is exhibited that the dielectric gradient has a nontrivial influence on the effective pyroelectric coefficient, but has a little influence on the polarization offset; and the polarization gradient plays an important role in the abnormal hysteresis loop phenomenon of the co.mpositionally step-like graded ferroelectric structures. Moreover, the origin of the polarization offset is explored,which can be attributed to the polarization gradient in the compositionally step-like graded structure.

  10. Investigation of the durability of a pyroelectric neutron source and secondary electron suppression

    Energy Technology Data Exchange (ETDEWEB)

    Friske, Eduard; Deuter, Gerhard; Jochum, Josef [Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany)

    2015-04-15

    The performance of a pyroelectric neutron source depends on several factors, such as the achieved high voltage, deuterium gas pressure and the tip geometry. Here we present measurements to investigate the dependency of the neutron production on the high voltage specifically and discuss the interdependency with other factors. In addition we present results showing that a biased grid in front of the target, which is a common way to capture secondary electrons, does not have any significant effect on the amount of electrons streaming back to the pyroelectric crystal. This indicates that the bulk of these electrons does not originate from the target but from a different source. (orig.)

  11. Preliminary validation results of an ASIC for the readout and control of near-infrared large array detectors

    Science.gov (United States)

    Pâhlsson, Philip; Meier, Dirk; Otnes Berge, Hans Kristian; Øya, Petter; Steenari, David; Olsen, Alf; Hasanbegovic, Amir; Altan, Mehmet A.; Najafiuchevler, Bahram; Talebi, Jahanzad; Azman, Suleyman; Gheorghe, Codin; Ackermann, Jörg; Mæhlum, Gunnar

    2015-06-01

    In this paper we present initial test results of the Near Infrared Readout and Controller ASIC (NIRCA), designed for large area image sensors under contract from the European Space Agency (ESA) and the Norwegian Space Center. The ASIC is designed to read out image sensors based on mercury cadmium telluride (HgCdTe, or MCT) operating down to 77 K. IDEAS has developed, designed and initiated testing of NIRCA with promising results, showing complete functionality of all ASIC sub-components. The ASIC generates programmable digital signals to clock out the contents of an image array and to amplify, digitize and transfer the resulting pixel charge. The digital signals can be programmed into the ASIC during run-time and allows for windowing and custom readout schemes. The clocked out voltages are amplified by programmable gain amplifiers and digitized by 12-bit, 3-Msps successive approximation register (SAR) analogue-to-digital converters (ADC). Digitized data is encoded using 8-bit to 10-bit encoding and transferred over LVDS to the readout system. The ASIC will give European researchers access to high spectral sensitivity, very low noise and radiation hardened readout electronics for astronomy and Earth observation missions operating at 77 K and room temperature. The versatility of the chip makes the architecture a possible candidate for other research areas, or defense or industrial applications that require analog and digital acquisition, voltage regulation, and digital signal generation.

  12. Continuous-wave near-photon counting spectral imaging detector in the mid-infrared by upconversion

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    2013-01-01

    Low noise upconversion of IR images by three-wave mixing, can be performed with high efficiency when mixing the object radiation with a powerful laser field inside a highly non-linear crystal such as periodically poled Lithium Niobate. Since IR cameras are expensive and have high levels of intrin......Low noise upconversion of IR images by three-wave mixing, can be performed with high efficiency when mixing the object radiation with a powerful laser field inside a highly non-linear crystal such as periodically poled Lithium Niobate. Since IR cameras are expensive and have high levels...... high-end IR cameras have read noise of hundreds of electrons. The dark noise for infrared cameras based on semiconductor materials is also substantially higher than for silicon cameras, typical values being millions of electrons per pixel per second for cryogenically cooled cameras whereas peltier...... cooled CCD cameras have dark noise measured in fractions of electrons per pixel per second. An ideal solution thus suggest the combination of an efficient low noise image wavelength conversion system combined with low noise silicon based cameras for low noise imaging in the IR region. We discuss image...

  13. Attenuated total internal reflection infrared microspectroscopic imaging using a large-radius germanium internal reflection element and a linear array detector.

    Science.gov (United States)

    Patterson, Brian M; Havrilla, George J

    2006-11-01

    The number of techniques and instruments available for Fourier transform infrared (FT-IR) microspectroscopic imaging has grown significantly over the past few years. Attenuated total internal reflectance (ATR) FT-IR microspectroscopy reduces sample preparation time and has simplified the analysis of many difficult samples. FT-IR imaging has become a powerful analytical tool using either a focal plane array or a linear array detector, especially when coupled with a chemometric analysis package. The field of view of the ATR-IR microspectroscopic imaging area can be greatly increased from 300 x 300 microm to 2500 x 2500 microm using a larger internal reflection element of 12.5 mm radius instead of the typical 1.5 mm radius. This gives an area increase of 70x before aberrant effects become too great. Parameters evaluated include the change in penetration depth as a function of beam displacement, measurements of the active area, magnification factor, and change in spatial resolution over the imaging area. Drawbacks such as large file size will also be discussed. This technique has been successfully applied to the FT-IR imaging of polydimethylsiloxane foam cross-sections, latent human fingerprints, and a model inorganic mixture, which demonstrates the usefulness of the method for pharmaceuticals.

  14. Theoretical investigation of tensile strained GeSn waveguide with Si₃N₄ liner stressor for mid-infrared detector and modulator applications.

    Science.gov (United States)

    Zhang, Qingfang; Liu, Yan; Yan, Jing; Zhang, Chunfu; Hao, Yue; Han, Genquan

    2015-03-23

    We theoretically investigate a tensile strained GeSn waveguide integrated with Si₃N₄ liner stressor for the applications in mid-infrared (MIR) detector and modulator. A substantial tensile strain is induced in a 1 × 1 μm² GeSn waveguide by the expansion of 500 nm Si₃N₄ liner stressor and the contour plots of strain are simulated by the finite element simulation. Under the tensile strain, the direct bandgap E(G,Γ) of GeSn is significantly reduced by lowering the Γ conduction valley in energy and lifting of degeneracy of valence bands. Absorption coefficients of tensile strained GeSn waveguides with different Sn compositions are calculated. As the Si₃N₄ liner stressor expands by 1%, the cut-off wavelengths of tensile strained Ge(0.97)Sn(0.03), Ge(0.95)Sn(0.05), and Ge(0.90)Sn(0.10) waveguide photodetectors are extended to 2.32, 2.69, and 4.06 μm, respectively. Tensile strained Ge(0.90)Sn(0.10) waveguide electro-absorption modulator based on Franz-Keldysh (FK) effect is demonstrated in theory. External electric field dependence of cut-off wavelength and propagation loss of tensile strained Ge(0.90)Sn(0.10) waveguide is observed, due to the FK effect.

  15. 红外单光子探测器定标方法研究%CALIBRATION METHOD STUDY FOR INFRARED SINGLE-PHOTON DETECTORS

    Institute of Scientific and Technical Information of China (English)

    马伊平; 宫铖; 丁漪; 冯瑜

    2015-01-01

    紫外激光器输出的355 nm激光泵浦BBO晶体,采用晶体的I类相位匹配,利用晶体的角度调谐特性得到的红外波段光源应用于单光子探测器定标,提出了利用参量下转换产生的纠缠光子对定标SPCM单光子探测器量子效率的方法,介绍了实验原理和定标装置。%355 nm UV laser output laser pumping BBO crystal, using I phase matching crystal, infrared light source utilizing crystal angle tuning characteristics are applied to the single-photon detector calibration. We propose the use of parametric down conversion produce entangled photons calibrate SPCM quantum efficiency of the method. We also introduce the principle and experiment of calibration device.

  16. La détection infrarouge avec les plans focaux non refroidis : état de l'artUncooled focal plane infrared detectors: the state of the art

    Science.gov (United States)

    Tissot, Jean-Luc

    2003-12-01

    The emergence of uncooled detectors has opened new opportunities for IR detection for both military and commercial applications. Development of such devices involves a lot of trade-offs between the different parameters that define the technological stack. These trade-offs explain the number of different architectures that are under worldwide development. The key factor is to find a high sensitivity and low noise thermometer material compatible with silicon technology in order to achieve high thermal isolation in the smallest area as possible. Ferroelectric thermometer based hybrid technology and electrical resistive thermometer based (microbolometer) technology are under development. LETI and ULIS have chosen from the very beginning to develop first a monolithic microbolometer technology fully compatible with commercially available CMOS technology and secondly amorphous silicon based thermometer. This silicon approach has the greatest potential for reducing infrared detector manufacturing cost. After the development of the technology, the transfer to industrial facilities has been performed in a short period of time and the production is now ramping up with ULIS team in new facilities. LETI and ULIS are now working to facilitate the IRFPA integration into equipment in order to address a very large market. Achievement of this goal needs the development of smart sensors with on-chip advanced functions and the decrease of manufacturing cost of IRFPA by decreasing the pixel pitch and simplifying the vacuum package. We present in this paper the technology developed by CEA/LETI and its improvement for being able to designs 384×288 and 160×120 arrays with a pitch of 35 μm. Thermographic application needs high stability infrared detector with a precise determination of the amount of absorbed infrared flux. Hence, infrared detector with internal temperature stabilized shield has been developed and characterized. These results will be presented. To cite this article: J

  17. Realization of an integrated VDF/TrFE copolymer-on-silicon pyroelectric sensor

    NARCIS (Netherlands)

    Setiadi, D.; Regtien, P.P.L.; Sarro, P.M.

    1995-01-01

    An integrated pyroelectric sensor based on a vinylidene fluoride trifluoroethylene (VDF/TrFE) copolymer is presented. A silicon substrate that contains FET readout electronics is coated with the VDF/TrFE copolymer film using a spin-coating technique. On-chip poling of the copolymer has been applied

  18. Effect of dielectrophoretic structuring on piezoelectric and pyroelectric properties of lead titanate-epoxy composites

    NARCIS (Netherlands)

    Khanbareh, H.; Zwaag, S. van der; Groen, W.A.

    2014-01-01

    Functional granular composites of lead titanate particles in an epoxy matrix prepared by dielectrophoresis show enhanced dielectric, piezoelectric and pyroelectric properties compared to 0-3 composites for different ceramic volume content from 10% to 50%. Two structuring parameters, the interparticl

  19. A 3 x 1 Integrated Pyroelectric Sensor Based on VDF/TrFE Copolymer

    NARCIS (Netherlands)

    Setiadi, D.; Sarro, P.M.; Regtien, P.P.L.

    1995-01-01

    This paper presents an integrated pyroelectric sensor based on a Vinylidene Fluoride TriFluoroEthylene (VDF/TrFE) copolymer. A silicon substrate that contains FET readout electronics is coated with the VDF/TrFE copolymer film using a spin-coating technique. On-chip poling of the copolymer has been a

  20. A 3x1 integrated pyroelectric sensor based on VDF/TrFE copolymer

    NARCIS (Netherlands)

    Setiadi, D.; Sarro, P.M.; Regtien, P.P.L.

    1996-01-01

    This paper presents an integrated pyroelectric sensor based on a vinylidene fluoride¿trifluoroethylene (VDF/TrFE) copolymer. A silicon substrate that contains field-effect transistor (FET) readout electronics is coated with the VDF/TrFE copolymer film using a spin-coating technique. On-chip poling o

  1. The Third Way of Thermal-Electric Conversion beyond Seebeck and Pyroelectric Effects

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Jie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-02-14

    Thermal-electric conversion is crucial for smart energy control and harvesting, such as thermal sensing and waste heat recovering. So far, people are aware of only two ways of direct thermal-electric conversion, Seebeck and pyroelectric effects, each with distinct working conditions and limitations. Here, we report the third way of thermal-electric conversion beyond Seebeck and pyroelectric effects. In contrast to Seebeck effect that requires spatial temperature difference, the-third-way converts the time-dependent ambient temperature fluctuation into electricity, similar to the behavior of pyroelectricity. However, the-third-way is also distinct from pyroelectric effect in the sense that it does not require polar materials but applies to general conducting systems. We demonstrate that the-third-way results from the temperature-fluctuation-induced dynamical charge redistribution. It is a consequence of the fundamental nonequilibrium thermodynamics and has a deep connection to the topological phase in quantum mechanics. Our findings expand our knowledge and provide new means of thermal-electric energy harvesting.

  2. First Principle Based Computation of Pyroelectricity in LiNbO3

    Science.gov (United States)

    Peng, Q.; Cohen, R. E.

    2010-03-01

    Pyroelectricity is of current interest since the discovery of particle acceleration of aqueous ions from changes in temperature at pyroelectric surfaces sufficient to generate hard X-rays[1] as well as neutrons via fusion[2]. We computed the pyroelectric coefficients in LiNbO3 from molecular dynamic simulation with DLPOLY using a shell model potential fitted to Density Functional Theory computations results. The potential was constructed by fitting energies and forces, as well as phonon frequencies and eigenvectors, Born effective charges, and dielectric constants computed from density functional perturbation theory using ABINT. The secondary pyroelectric effect is computed from density functional theory. The spontaneous polarizations were calculated using the Berry phase method. The coefficient of thermal expansivity, elastic moduli, elastic compliances, piezoelectric stress constants and piezoelectric strain constants are computed by linear response and lattice dynamics computations. [1] J. D. Brownridge and S. Raboy, Journal of Applied Physics 86, 640 (1999). [2] B. Naranjo, J. Gimzewski, and S. Putterman, Nature 434, 1115 (2005).

  3. Low background infrared (LBIR) facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Low background infrared (LBIR) facility was originally designed to calibrate user supplied blackbody sources and to characterize low-background IR detectors and...

  4. Triboelectric-pyroelectric-piezoelectric hybrid cell for high-efficiency energy-harvesting and self-powered sensing.

    Science.gov (United States)

    Zi, Yunlong; Lin, Long; Wang, Jie; Wang, Sihong; Chen, Jun; Fan, Xing; Yang, Po-Kang; Yi, Fang; Wang, Zhong Lin

    2015-04-08

    A triboelectric-pyroelectric-piezoelectric hybrid cell, consisting of a triboelectric nanogenerator and a pyroelectric-piezoelectric nanogenerator, is developed for highly efficient mechanical energy harvesting through multiple mechanisms. The excellent performance of the hybrid cell enhances the energy-harvesting efficiency significantly (by 26.2% at 1 kΩ load resistance), and enables self-powered sensing, which will lead to a variety of advanced applications.

  5. Optimized Pyroelectric Vidicon Thermal Imager. Volume I. Thermal Imager. Volume 1a. Rain Camera. Volume 1b. Reticulation.

    Science.gov (United States)

    1979-06-01

    the pan mode. Reticulation of the TGS family of pyroelectric targets was demonstrated using standard ion-milling techniques. Reticula - tion of DTGFB...9 A technique for pedestal noise suppression (PNS) is being investigated as part of Contract DAAK70-77-C-0138 (Return Beam/Isocon Pyroelectric...reticulation studies under the basic contract because TGFB and DTGFB were not available in sufficient quantities during the early part of the program. The

  6. Minimization of pyroelectric effects in relaxor-PbTiO{sub 3} crystals for piezoelectric sensors

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yanxue, E-mail: yanxuetang@gmail.com [Key Laboratory of Optoelectronic Material and Device, Shanghai Normal University, Shanghai 200234 (China); Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 (United States); Shen, Zongyang [Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 (United States); School of Materials Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403 (China); Zhang, Shujun; Jiang, Wenhua [Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 (United States); Luo, Jun [TRS Technologies Inc., 2820 E. College Ave., State College, PA 16801 (United States); Shrout, Thomas R. [Materials Research Institute, The Pennsylvania State University, University Park, PA 16802 (United States)

    2014-05-01

    To minimize pyroelectric effects while keeping high piezoelectric effects in relaxor-PbTiO{sub 3} single crystals, the crystallographic orientation dependence of the pyroelectric and piezoelectric coefficients were investigated for binary (1 − x)Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–xPbTiO{sub 3} (PMN–PT), ternary (1 − x − y)Pb(In{sub 1/2}Nb{sub 1/2})O{sub 3}–yPb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}–xPbTiO{sub 3} (PIN–PMN–PT) and Mn-doped PIN–PMN–PT single crystals with the “4R” multidomain state. The secondary pyroelectric coefficients were calculated from the thermodynamic inter-relationship between the piezoelectric, elastic, and thermal expansion coefficients, being on the order of (1.16–1.23) × 10{sup −4} C m{sup −2} K{sup −1} for binary crystals and (0.97–2.03) × 10{sup −4} C m{sup −2} K{sup −1} for ternary ones. The primary pyroelectric coefficients were –(6.73–6.84) × 10{sup −4} C m{sup −2} K{sup −1} and −(5.44–6.43) × 10{sup −4} C m{sup −2} K{sup −1} for binary and ternary crystals, respectively. The pyroelectric coefficients could be reduced by matrix rotation, but at the cost of decreasing longitudinal piezoelectric coefficients d{sub 33}. Of particular interest is that the maximum piezoelectric coefficients d{sub 24}{sup ∗} at θ = ±55{sup o} and d{sub 34}{sup ∗} at θ = ±35{sup o} by a counterclockwise rotation of θ about the X axis (θ is the rotation angle about the coordinate axes), or d{sub 15}{sup ∗} at θ = ±55{sup o}, and d{sub 35}{sup ∗} at θ = ±35{sup o} by a counterclockwise rotation the Y axis, were found on the order of 3000 pC N{sup −1}. The corresponding pyroelectric coefficients could be reduced by ∼20%. The reduced pyroelectric coefficients that can contribute to decrease undesirable output signals, together with the high piezoelectric coefficients, enable relaxor-PT crystals as favorable candidates for high

  7. 阻挡杂质带红外探测器中的界面势垒效应∗%Interfacial barrier effects in blo cked impurity band infrared detectors

    Institute of Scientific and Technical Information of China (English)

    廖开升; 李志锋; 李梁; 王超; 周孝好; 戴宁; 李宁

    2015-01-01

    Blocked impurity band (BIB) detectors, developed from extrinsic detectors, have long been employed for ground-based and airborne astronomical imaging and photon detections. They are the state-of-the-art choice for highly sensitive detection from mid-infrared to far-infrared radiation. In this work, we demonstrate the existence of an interfacial barrier in blocked impurity band structures by evidence of temperature-dependent dark currents, bias-dependent photocurrent spectra and corresponding theoretical calculations. The origin of the build-in field is studied. The temperature-dependent characteristics of space charge effects are also investigated in detail. It is found that at higher temperature (T >14 K), the space charge influence is negligible, and the interfacial barrier is mainly caused by bandgap narrowing effects. Based on interfacial barrier effects, a dual-excitation model is proposed to clarify the band structure of BIB detectors. The photocurrent spectra related to the two excitation processes, i.e., the direct excitation over the interfacial barrier and excitation to the band edge with subquent tunneling into blocking layer, are successfully extracted and agree reasonably well with the calculated band structure results. The effects of interfacial barrier on the photocurrent spectrum, peak responsivity and internal quantum efficiency of the devices are investigated. With the consideration of interfacial barrier effects, the calculated peak responsivity shows good agreement with the experimental result. It is suggested that interfacial barrier effects should be considered for successfully designing the BIB detectors. Additionally, the build-in field is found to equivalently lower the critical field for impact ionization. This study provides a better understanding of the working mechanism in BIB detectors and also a better device optimization.

  8. Pyroelectricity of Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} films grown by sol–gel process on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Moalla, R. [Institut des Nanotechnologies de Lyon, INL-CNRS UMR 5270, Ecole Centrale de Lyon, Bâtiment F7, 36 av. Guy de Collongue, 69134 Ecully Cedex (France); Le Rhun, G. [CEA, LETI, MINATEC Campus, 17 Rue des Martyrs, 38054 Grenoble (France); Defay, E. [CEA, LETI, MINATEC Campus, 17 Rue des Martyrs, 38054 Grenoble (France); Luxembourg Institute of Science and Technology (LIST), Materials Research & Technology Department (MRT), 41 Rue du Brill, L-4422 Belvaux (Luxembourg); Baboux, N. [Institut des Nanotechnologies de Lyon, INL-CNRS UMR 5270, INSA de Lyon, Bâtiment Blaise Pascal, 7 avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Sebald, G. [Laboratoire de Génie Electrique et Ferroélectricité, LGEF EA 682, INSA de Lyon, Bâtiment Gustave Ferrié, 8 rue de la Physique, 69621 Villeurbanne Cedex (France); Bachelet, R., E-mail: romain.bachelet@ec-lyon.fr [Institut des Nanotechnologies de Lyon, INL-CNRS UMR 5270, Ecole Centrale de Lyon, Bâtiment F7, 36 av. Guy de Collongue, 69134 Ecully Cedex (France)

    2016-02-29

    Pyroelectric Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} films have been grown by sol–gel process on Si(001). Intrinsic pyroelectric coefficient has been measured through ferroelectric loops recorded at different temperatures and is about − 300 μC/m{sup 2}K. Corresponding converted pyroelectric power density is estimated to be ~ 1 mW/cm{sup 3} for a temperature variation of 10 °C every 6 s. Pyroelectric response of these films has been confirmed by direct measurements of the pyroelectric current with temperature variations at zero electric field. These results are of high interest for integrated thermally-sensitive devices. - Highlights: • Functional oxide films are grown by low-cost sol–gel process and spin-coating. • Pyroelectric Pb(Zr,Ti)O{sub 3} films are integrated in planar capacitor structure on Si. • Bulk intrinsic pyroelectric coefficient is measured: ‐ 300 μC/m{sup 2}K. • Converted pyroelectric energy is estimated: 6 mJ/cm{sup 3} per 10 °C thermal cycle. • Direct measurements of pyroelectricity are done on integrated oxide thin films.

  9. Barrier Infrared Detector (BIRD) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — JPL will design, fabricate, and fully characterize a 640x512 format HOT-BIRD FPA with increased quantum efficiency and extended spectral coverage. Unlike the small...

  10. Infrared detector device inspection system

    Science.gov (United States)

    Soehnel, Grant; Bender, Daniel A.

    2016-08-09

    Methods and apparatuses for identifying carrier lifetimes are disclosed herein. In a general embodiment, a beam of light is sent to a group of locations on a material for an optical device. Photons emitted from the material are detected at each of the group of locations. A carrier lifetime is identified for each of the group of locations based on the photons detected from each of the group of locations.

  11. Contactless Temperature Measurement System Based on Pyroelectric Sensor%热释电传感器的非接触式测控系统设计

    Institute of Scientific and Technical Information of China (English)

    叶健成

    2013-01-01

    Basic principles of using pyroelectric infrared sensor for non-contact measurement,infrared temperature measurement system structure and composition of signal processing circuit are introduced in this paper.On this basis,the paper designs and implements a set of non-contact infrared temperature measurement device,it uses the device to measure movement target surface temperature.When it simulates the application of actual scene,it can realize the accurate measurement of the distant pedestrian body temperature,also it increases the high temperature alarm circuit and bluetooth wireless communication module,and expands the using function.%介绍了利用热释电红外传感器进行非接触式测温的基本原理、红外测温系统结构和信号处理电路的组成.以此为基础,设计了一套非接触式红外测温装置,用该装置测定了移动目标表面温度.在模拟实际场景应用时,实现了对较远距离的运动行人体温的准确测量;装置还增加了高温报警电路和蓝牙无线通信模块,丰富了使用功能.

  12. The Control Method for Pyroelectric Chopper%热释电斩波器控制

    Institute of Scientific and Technical Information of China (English)

    王敏; 李晶; 朱洪洋; 刘愚; 郭小军; 陈如造; 罗凤旺; 秦伟; 朱光明

    2014-01-01

    斩波器是热释电型热像仪的重要组成部份,其平稳、匀速且按要求相位精确地运转,关系到整机成像质量的好坏。提出了一种对热释电斩波器进行闭环控制的方法,该方法的使用,解决了斩波器的控制问题。%Chopper is the important part of the pyroelectric thermal imager. The stable and uniform operation of chopper is related to the imaging quality. This paper presents a method about the closed-loop control for pyroelectric chopper, which solves the problem of the chopper control.

  13. Piezo- and pyroelectricity of a polymer-foam space-charge electret

    Science.gov (United States)

    Neugschwandtner, Gerhard S.; Schwödiauer, Reinhard; Bauer-Gogonea, Simona; Bauer, Siegfried; Paajanen, Mika; Lekkala, Jukka

    2001-04-01

    Charged closed-cell polypropylene polymer foams are highly sensitive and broadband piezoelectric materials with a quasistatic piezoelectric d33 coefficient about 250 pC/N and a dynamic d33 coefficient of 140 pC/N at 600 kHz. The piezoelectric coefficient is much larger than that of ferroelectric polymers, like polyvinylidene fluoride, and compares favorably with ferroelectric ceramics, such as lead zirconate titanate. The pyroelectric coefficient p3=0.25 μC/m2 K is small in comparison to ferroelectric polymers and ferroelectric ceramics. The low density, small pyroelectric coefficient and high piezoelectric sensitivity make charged polymer foams attractive for a wide range of sensor and transducer applications in acoustics, air-borne ultrasound, medical diagnostics, and nondestructive testing.

  14. Nanotubes, nanorods and nanowires having piezoelectric and/or pyroelectric properties and devices manufactured therefrom

    Science.gov (United States)

    Russell, Thomas P [Amherst, MA; Lutkenhaus, Jodie [Wethersfield, CT

    2012-05-15

    Disclosed herein is a device comprising a pair of electrodes; and a nanotube, a nanorod and/or a nanowire; the nanotube, nanorod and/or nanowire comprising a piezoelectric and/or pyroelectric polymeric composition; the pair of electrodes being in electrical communication with opposing surfaces of the nanotube, nanorod and/or a nanowire; the pair of electrodes being perpendicular to a longitudinal axis of the nanotube, nanorod and/or a nanowire.

  15. Pyroelectric generation of 2D spatial soliton sets in a bulk of lithium niobate crystal

    Science.gov (United States)

    Ryabchenok, V.; Shandarov, V.; Perin, A.

    2017-06-01

    The generation of two-dimensional bright spatial soliton sets in lithium niobate sample has been experimentally demonstrated at light wavelength of 532 nm, contribution of pyroelectric effect into nonlinear optical response of the crystal, and spatial modulation of one-dimensional beam along direction normal to the crystal optical axis. Diameters of soliton beams and channel waveguides formed within the crystal bulk by these solitons are near to 20 μm at light polarization corresponding to extraordinary wave of the crystal.

  16. The study of dielectric, pyroelectric and piezoelectric properties on hot pressed PZT-PMN systems

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Geetika; Umarji, A. M. [Materials Research Centre, Indian Institute of Science, Bangalore-560 012 (India); Maglione, Mario [ICMCB, Universite de Bordeaux,-CNRS, 87, Av Dr Schweitzer 33806 Pessac (France)

    2012-12-15

    Hot uniaxial pressing technique has been adopted for the densification of PZT-PMN system with an aim to yield dense ceramics and to lower the sintering temperature and time for achieving better and reproducible electronic properties. The ceramics having >97% theoretical density and micron size grains are investigated for their dielectric, pyroelectric and piezoelectric properties. The effect of Li and Mn addition has also been studied.

  17. The study of dielectric, pyroelectric and piezoelectric properties on hot pressed PZT-PMN systems

    Directory of Open Access Journals (Sweden)

    Geetika Srivastava

    2012-12-01

    Full Text Available Hot uniaxial pressing technique has been adopted for the densification of PZT-PMN system with an aim to yield dense ceramics and to lower the sintering temperature and time for achieving better and reproducible electronic properties. The ceramics having >97% theoretical density and micron size grains are investigated for their dielectric, pyroelectric and piezoelectric properties. The effect of Li and Mn addition has also been studied.

  18. Timing A Pulsed Thin Film Pyroelectric Generator For Maximum Power Denisty

    Science.gov (United States)

    Smith, A. N.; Hanrahan, B. M.; Neville, C. J.; Jankowski, N. R.

    2016-11-01

    Pyroelectric thermal-to-electric energy conversion is accomplished by a cyclic process of thermally-inducing polarization changes in the material under an applied electric field. The pyroelectric MEMS device investigated consisted of a thin film PZT capacitor with platinum bottom and iridium oxide top electrodes. Electric fields between 1-20 kV/cm with a 30% duty cycle and frequencies from 0.1 - 100 Hz were tested with a modulated continuous wave IR laser with a duty cycle of 20% creating temperature swings from 0.15 - 26 °C on the pyroelectric receiver. The net output power of the device was highly sensitive to the phase delay between the laser power and the applied electric field. A thermal model was developed to predict and explain the power loss associated with finite charge and discharge times. Excellent agreement was achieved between the theoretical model and the experiment results for the measured power density versus phase delay. Limitations on the charging and discharging rates result in reduced power and lower efficiency due to a reduced net work per cycle.

  19. Pyroelectric crystal D-D and D-T neutron generators

    Science.gov (United States)

    Danon, Y.

    2012-04-01

    Pyroelectric neutron generators are a recent development utilizing the pyroelectric effect to produce an accelerating electric field and thus enabling creation of small electron and ion accelerators without external high voltage power supply. The principle of operation includes a pyroelectric crystal (LiTaO3 for example) placed in vacuum and simple heating (or cooling) of the crystal to cause a change in polarization. The change in polarization creates free charges on the faces of the clyndrical z-cut crystal and due to its small capacitance this creates a high potential between one crystal face to the other which is placed at ground potential. To produce neutrons the crystal is placed in low pressure deuterium gas and when the crystal is heated or cooled it ionizes the gas and accelerates deuterium ions towards a deuterated or tritated target. A configuration with two crystals can double the acceleration potential and thus increase neutron production. When operating such a device x-rays with energy over 200 keV about 105 neutrons per heating cycle can be produced. Research is focused on improving the neutron yield, the emission reproducibility, and shortening the heating cycle. Neutron generators based on this technology can be made small portable and relatively cheap compared to sealed tube technology. Further development is needed in order to increase the neutron yield closer to the theoretical limit for a specific crystals size.

  20. DIELECTRIC AND PYROELECTRIC PROPERTIES OF THE COMPOSITES OF FERROELECTRIC CERAMIC AND POLY(VINYL CHLORIDE

    Directory of Open Access Journals (Sweden)

    M.Olszowy

    2003-01-01

    Full Text Available The dielectric and pyroelectric properties of lead zirconate titanate/poly(vinyl chloride [PZT/PVC] and barium titanate/poly(vinyl chloride [BaTiO3/ PVC] composites were studied. Flexible composites were fabricated in the thin films form (200-400 μm by hot-pressed method. Powders of PZT or BaTiO3 in the shape of ≤ 75 μm ceramics particles were dispersed in a PVC matrix, providing composites with 0-3} connectivity. Distribution of the ceramic particles in the polymer phase was examined by scanning electron microscopy. The analysis of the thermally stimulated currents (TSC have also been done. The changes of dielectric and pyroelectric data on composites with different contents of ceramics up to 40% volume were investigated. The dielectric constants were measured in the frequency range from 600 Hz to 6 MHz at room temperature. The pyroelectric coefficient for BaTiO3/PVC composite at 343 K is about 35 μC/m2K which is higher than that of β-PVDF (10 μC/m2 K.

  1. Correlation between intrinsic dipole moment and pyroelectric coefficient of Fe-Mg tourmaline

    Institute of Scientific and Technical Information of China (English)

    Chang-chun Zhao; Li-bing Liao; Jie Xing

    2014-01-01

    Single-crystal X-ray diffraction structural data of four Fe-Mg tourmalines with different Fe contents from Xinjiang, Sichuan, and Yunnan Provinces, China, were collected at room temperature and-100ºC. The intrinsic dipole moments of polyhedra and the total intrinsic dipole moment of the unit cell were calculated. By comparing the intrinsic electric dipole moments of the X, Y, Z, T, and B site polyhedra, it is found that the T site polyhedron makes the greatest contribution to the total intrinsic dipole moment. The pyroelectric coefficients of four Fe-Mg tourmalines were experimentally determined, and the influence of intrinsic dipole moments on their pyroelectric properties was inves-tigated. The experimental results show that, compared with the case at room temperature, the intrinsic dipole moments change with the total Fe content at-100ºC in a completely different way. With the decrease of temperature, the total intrinsic dipole moments of tourmaline de-crease. Over the same temperature interval, the pyroelectric coefficients increase with the increase in intrinsic dipole moment.

  2. Pyroelectric properties and electrical conductivity in samarium doped BiFeO 3 ceramics

    KAUST Repository

    Yao, Yingbang

    2012-06-01

    Samarium (Sm 3+) doped BiFeO 3 (BFO) ceramics were prepared by a modified solid-state-reaction method which adopted a rapid heating as well as cooling during the sintering process. The pyroelectric coefficient increased from 93 to 137 μC/m 2 K as the Sm 3+ doping level increased from 1 mol% to 8 mol%. Temperature dependence of the pyroelectric coefficient showed an abrupt decrease above 80 °C in all samples, which was associated with the increase of electrical conductivity with temperature. This electrical conduction was attributed to oxygen vacancy existing in the samples. An activation energy of ∼0.7 eV for the conduction process was found to be irrespective of the Sm 3+ doping level. On the other hand, the magnetic Néel temperature (T N) decreased with increasing Sm 3+ doping level. On the basis of our results, the effects of Sm doping level on the pyroelectric and electrical properties of the BFO were revealed. © 2011 Elsevier Ltd. All rights reserved.

  3. Infrared Imaging

    Science.gov (United States)

    Danchi, W.; Lawson, P.; Absil, O.; Akeson, R.; Bally, J.; Barry, R.; Beichman, C.; Belu, A.; Boyce, M.; Breckinridge, J.; Burrows, A.; Chen, C.; Cole, D.; Crisp, D.; Danner, R.; Deroo, P.; Coudé du Foresto, V.; Defrère, D.; Ebbets, D.; Falkowski, P.; Gappinger, R.; Haugabook, I.; Hanot, C.; Henning, T.; Hinz, P.; Hollis, J.; Hunyadi, S.; Hyland, D.; Johnston, K.; Kaltenegger, L.; Kasting, J.; Kenworthy, M.; Ksendzov, A.; Lane, B.; Laughlin, G.; Lay, O.; Liseau, R.; Lopez, B.; Millan-Gabet, R.; Martin, S.; Mawet, D.; Mennesson, B.; Monnier, J.; Murakami, N.; Noecker, C.; Nishikawa, J.; Pesesen, M.; Peters, R.; Quillen, A.; Ragland, S.; Rinehart, S.; Rottgering, H.; Scharf, D.; Serabyn, G.; Tamura, M.; Tehrani, M.; Traub, W.; Unwin, S.; Wilner, D.; Woilliez, J.; Woolf, N.; Zhao, M.

    2009-03-01

    A mid-infrared mission would enable the detection of biosignatures of Earth-like exoplanets around more than 150 nearby stars. The mid-infrared spectral region is attractive for characterizing exoplanets because contrast with the parent star brightness is more favorable than in the visible (10 million vs. 10 billion), and because mid-infrared light probes deep into a planet's troposphere. Furthermore, the mid-infrared offers access to several strong molecular features that are key signs of life, and also provides a measure of the effective temperature and size of a planet. Taken together, an infrared mission plus a visible one would provide a nearly full picture of a planet, including signs of life; with a measure of mass from an astrometric mission, we would have a virtually complete picture. A small infrared mission would have several telescopes that are rigidly connected, with a science return from the detection and characterization of super-Earth sized to larger planets near the HZ, plus a direct measure of the exozodi brightness in the HZ. In a large infrared mission, with formation-flying telescopes, planets from an Earth-twin and upwards in mass could be detected and characterized, as well as the exozodi. If proceeded by an astrometric mission, the detection phase could be skipped and the mission devoted to characterization, as in the visible case; lacking an astrometric mission, an infrared one could proceed alone, as was discussed for a visible coronograph, and with similar caveats. The technology needed for a large formation-flying mission is similar to that for a small connected-element one (e.g., cryogenics and detectors), with the addition of formationflying technology. The technology is now in hand to implement a probe-scale mission; starlight suppression has even been demonstrated to meet the requirements of a flagship mission. However, additional development of formation-flying technology is needed, particularly in-space testing of sensors and

  4. Progress In Materials Synthesis And Processing Of Barium Titanium Oxide (BaTiO3) and Barium Strontium Titanium Oxide (BaTiSrO3) Films For Uncooled Infrared (IR) Detector Applications

    Science.gov (United States)

    2011-12-01

    This wavelength is ideal for enhancing the near IR photoresponse of solar cells , and we are transitioning this technology to our quantum dot solar ...nanoparticles was also achieved using polyvinylpyrrolidone (PVP), which was found to facilitate the formation of stable colloids of BaTiO3 and thereby...processing parameters with the (pyro)electrical properties and IR responsiveness of the perovskite test structures. Based on the existing and preferred ARL

  5. Infrared Astronomy with Arrays: The Next Generation; Sunset Village, Los Angeles, CA, Oct. 1993

    Science.gov (United States)

    Mclean, Ian S.

    1994-01-01

    Conference papers on infrared array techniques and methods for infrared astronomy are presented. Topics covered include the following: infrared telescopes; infrared spectrometers; spaceborne astronomy; astronomical observatories; infrared cameras; imaging techniques; sky surveys; infrared photography; infrared photometry; infrared spectroscopy; equipment specifications; data processing and analysis; control systems; cryogenic equipment; adaptive optics; image resolution; infrared detector materials; and focal plane arrays.

  6. A Design of Signal Acquisition Module for 288 × 4 Long-wavelength Infrared Detectors%288×4长波红外探测器数据采集模块的设计

    Institute of Scientific and Technical Information of China (English)

    陈晓东

    2011-01-01

    针对288×4长波焦平面红外探测器组件的特点,设计了一个数据采集模块,以FPGA为核心,为探测器提供时序与控制信号,同时对探测器输出的四路红外模拟图像信号进行高精度的模数转换,然后将红外数字图像信号向后端传送.实验结果表明,采集到的红外图像具有噪声低、稳定性好等特点.当探测器在293 K黑体的照射下,并且积分时间为19μs时,整个红外图像采集系统的平均噪声等效温差(NETD)在30mK左右.%According to the characteristic of 288×4 LWIR CMOS Integrated Detector Dewar Cooler Assembly, a data acquisition module is designed based on FPGA to provide clock and control signals,translating four channels of infrared analog image signals to digital signals accurately, and then sending the infrared digital image signals to the back end.Experimental results show that the collected infrared images have the characteristic of low noise and high stability.The average NETD of the whole infrared image collecting system is about 30 mK, when the detector is radiated by the 293 K blackbody and the integral time is set to 19 μs.

  7. GRAVITY detector systems

    Science.gov (United States)

    Mehrgan, Leander H.; Finger, Gert; Eisenhauer, Frank; Panduro, Johana

    2016-08-01

    GRAVITY is a second generation instrument for the VLT Interferometer, designed for high-precision narrow-angle astrometry and phase-referenced interferometric imaging in the K-band. It will combine the AO corrected beams of the four VLT telescopes. In total, the GRAVITY instrument uses five eAPD detectors four for the infrared wavefront sensors of each telescope and one for the fringe tracker. In addition two Hawaii2RG arrays are installed, one for the acquisition camera and one for the spectrometer. The SAPHIRA eAPD array is a newly developed near-infrared detector with sub-electron noise performance at frame rates > 1Kfps. For all seven detectors the ESO common controller, NGC, is used. This paper presents an overview and comparison of GRAVITY detector systems and their final performances at the telescope

  8. Graphene Ink Laminate Structures on Poly(vinylidene difluoride) (PVDF) for Pyroelectric Thermal Energy Harvesting and Waste Heat Recovery.

    Science.gov (United States)

    Zabek, Daniel; Seunarine, Kris; Spacie, Chris; Bowen, Chris

    2017-03-15

    Thermal energy can be effectively converted into electricity using pyroelectrics, which act as small scale power generator and energy harvesters providing nanowatts to milliwatts of electrical power. In this paper, a novel pyroelectric harvester based on free-standing poly(vinylidene difluoride) (PVDF) was manufactured that exploits the high thermal radiation absorbance of a screen printed graphene ink electrode structure to facilitate the conversion of the available thermal radiation energy into electrical energy. The use of interconnected graphene nanoplatelets (GNPs) as an electrode enable high thermal radiation absorbance and high electrical conductivity along with the ease of deposition using a screen print technique. For the asymmetric structure, the pyroelectric open-circuit voltage and closed-circuit current were measured, and the harvested electrical energy was stored in an external capacitor. For the graphene ink/PVDF/aluminum system the closed circuit pyroelectric current improves by 7.5 times, the open circuit voltage by 3.4 times, and the harvested energy by 25 times compared to a standard aluminum/PVDF/aluminum system electrode design, with a peak energy density of 1.13 μJ/cm(3). For the pyroelectric device employed in this work, a complete manufacturing process and device characterization of these structures are reported along with the thermal conductivity of the graphene ink. The material combination presented here provides a new approach for delivering smart materials and structures, wireless technologies, and Internet of Things (IoT) devices.

  9. Infrared Solar Physics

    Directory of Open Access Journals (Sweden)

    Matthew J. Penn

    2014-05-01

    Full Text Available The infrared solar spectrum contains a wealth of physical data about our Sun, and is explored using modern detectors and technology with new ground-based solar telescopes. The scientific motivation behind exploring these wavelengths is presented, along with a brief look at the rich history of observations here. Several avenues of solar physics research exploiting and benefiting from observations at infrared wavelengths from roughly 1000 nm to 12 400 nm are discussed, and the instrument and detector technology driving this research is briefly summarized. Finally, goals for future work at infrared wavelengths are presented in conjunction with ground and space-based observations.

  10. MgB2-Based Bolometer Array for Far Infra-Red Thermal Imaging and Fourier Transform Spectroscopy Applications

    Science.gov (United States)

    Lakew, B.; Aslam, S.; Brasunas, J.

    2012-01-01

    The mid-superconducting critical temperature (T(sub c) approximately 39 K) of the simple binary, intermetallic MgB, [1] makes it a very good candidate for the development of the next generation of electrooptical devices (e.g. [2]). In particular, recent advances in thin film deposition teclmiques to attain higb quality polycrystalline thin film MgB, deposited on SiN-Si substrates, with T(sub c) approximately 38K [3] coupled with the low voltage noise performance of the film [4] makes it higbly desirable for the development of moderately cooled bolometer arrays for integration into future space-bourne far infra-red (FIR) spectrometers and thermal mappers for studying the outer planets, their icy moons and other moons of interest in the 17-250 micrometer spectral wavelength range. Presently, commercially available pyroelectric detectors operating at 300 K have specific detectivity, D(*), around 7 x 10(exp 8) to 2 x 10(exp 9) centimeters square root of Hz/W. However, a MgB2 thin film based bolometer using a low-stress (less than 140 MPa) SiN membrane isolated from the substrate by a small thermal conductive link, operating at 38 K, promises to have two orders of magnitude higher specific detectivity [5][6].

  11. A mid-infrared carbon monoxide sensor system using wideband absorption spectroscopy and a single-reflection spherical optical chamber

    Science.gov (United States)

    Dong, Ming; Zheng, Chuantao; Miao, Shuzhuo; Song, Fang; Wang, Yiding

    2017-09-01

    A mid-infrared carbon monoxide (CO) sensor system based on a dual-channel differential detection method was developed using a broadband light source in the 4.60 μm wavelength region and a single-reflection spherical optical chamber with ∼0.373 m absorption path length. CO detection was realized by targeting the wideband strong absorption lines within 4.55-4.65 μm. A dual-channel pyroelectric detector as well as a self-developed digital signal processor (DSP) based orthogonal lock-in amplifier was employed to process CO sensing signal. A minimum detection limit of ∼0.5 ppm in volume (ppmv) was achieved with a measurement time of 6 s, based on an Allan deviation analysis of the sensor system. The response time (1000 → 0 ppmv) was determined to be ∼7 s for the CO sensor operation. Due to the characteristics of low detection limit, fast response time and high cost performance, the proposed sensor has relatively good prospect in coal-mining operation.

  12. Evaluation of the solid state dipole moment and pyroelectric coefficient of phosphangulene by multipolar modeling of X-ray structure factors

    DEFF Research Database (Denmark)

    Madsen, G.K.H.; Krebs, Frederik C; Lebech, B.;

    2000-01-01

    The electron density distribution of the molecular pyroelectric material phosphangulene has been studied by multipolar modeling of X-ray diffraction data. The "in-crystal" molecular dipole moment has been evaluated to 4.7 D corresponding to a 42% dipole moment enhancement compared with the dipole...... pyroelectric coefficients has been introduced by combining the derived dipole moment with temperature-dependent measurements of the unit cell volume. The derived pyroelectric coefficient of 3.8(7)x 10(-6) Cm-2K-1 is in very good agreement with the measured pyroelectric coefficient of p = 3 +/- 1 x 10(-6) Cm-2...... K-1. This method for obtaining the pyroelectric coefficient uses information from the X-ray diffraction experiment alone and can be applied to much smaller crystals than traditional methods....

  13. Study of the growth and pyroelectric properties of TGS crystals doped with aniline-family dipolar molecules

    Science.gov (United States)

    Zhang, Kecong; Song, Jiancheng; Wang, Min; Fang, Changshui; Lu, Mengkai

    1987-04-01

    TGS crystals doped with aniline-family dipolar molecules (aniline, 2-aminobenzoic acid, 3-aminobenzoic acid, 3-aminobenzene-sulphonic acid, 4-aminobenzenesulphonic acid and 4-nitroraniline) have been grown by the slow-cooling solution method. The influence of these dopants on the growth habits, crystal morphology pyroelectric properties, and structure parameters of TGS crystals has been systematically investigated. The effects of the domain structure of the seed crystal on the pyroelectric properties of the doped crystals have been studied. It is found that the spontaneous polarization (P), pyroelectric coefficient (lambda), and internal bias field of the doped crystals are slightly higher than those of the pure TGS, and the larger the dipole moment of the dopant molecule, the higher the P and lambda of the doped TGS crystal.

  14. EXPERIMENTAL SETUP FOR THE STUDY OF INFRARED SIGNALS OF DIFFERENT SOIL MOISTURE

    Directory of Open Access Journals (Sweden)

    A. N. Popov

    2013-01-01

    Full Text Available The article presents: structural scheme of the installation for measuring the infrared radiation of the soil in the range of 6-14 um; technical characteristics device ИКВП-01. The opportunities of use of pyroelectric sensors type MLX90614ESF were researched. Dependence of the temperature of soil from its humidity and dependence of the signal IR instrument of soil temperature and humidity are presented.

  15. 应用于红外成像导引头的非制冷焦平面探测器%Uncooled Focal Plane Arrays Detector Applied for Infrared Imaging Seeker

    Institute of Scientific and Technical Information of China (English)

    李煜; 白丕绩; 陶禹; 袁名松

    2016-01-01

    With great progress in fabrication technology, medium(large)scale, high temperature response and small pixel pitch UFPAs(Uncooled Focal Plane Arrays)detectors are produced. For its high cost-effectiveness, compactness and easy maintenance etc, seeker using UFPAs detector has become an important member in the infrared imaging seeker family. Some kinds of domestic and foreign representative weapons such as anti-tank missile, precision attack missile, precision guided bomb, anti-ship missile etc. and specifications of UFPAs used in infrared imaging guidance systems are introduced in detail. Finally, the characteristics and development trend of UFPAs for uncooled infrared imaging guidance systems are summarized.%随着非制冷探测器技术的迅猛发展,中大规模、高灵敏度的非制冷焦平面器件实现工程化应用.使用非制冷焦平面器件的红外成像导引头具有效费比高、结构紧凑、易维护等优点,已成为红外成像导引头的重要成员之一.介绍了国内外几款采用非制冷红外成像导引头的反坦克导弹、精确攻击导弹、精确炸弹、反舰导弹,以及所使用的非制冷焦平面器件的性能参数,总结了用于红外成像制导系统的非制冷焦平面器件的特点及发展趋势.

  16. Electrical properties of n-type GaSb substrates and p-type GaSb buffer layers for InAs/InGaSb superlattice infrared detectors

    Energy Technology Data Exchange (ETDEWEB)

    Mitchel, W. C., E-mail: William.Mitchel.1@us.af.mil; Haugan, H. J.; Mou, Shin; Brown, G. J. [Air Force Research Laboratory, Materials & Manufacturing Directorate, Wright-Patterson Air Force Base, Ohio 45433 (United States); Elhamri, S.; Berney, R. [University of Dayton, Department of Physics, Dayton, Ohio 45469 (United States)

    2015-09-15

    Lightly doped n-type GaSb substrates with p-type GaSb buffer layers are the preferred templates for growth of InAs/InGaSb superlattices used in infrared detector applications because of relatively high infrared transmission and a close lattice match to the superlattices. We report here temperature dependent resistivity and Hall effect measurements of bare substrates and substrate-p-type buffer layer structures grown by molecular beam epitaxy. Multicarrier analysis of the resistivity and Hall coefficient data demonstrate that high temperature transport in the substrates is due to conduction in both the high mobility zone center Γ band and the low mobility off-center L band. High overall mobility values indicate the absence of close compensation and that improved infrared and transport properties were achieved by a reduction in intrinsic acceptor concentration. Standard transport measurements of the undoped buffer layers show p-type conduction up to 300 K indicating electrical isolation of the buffer layer from the lightly n-type GaSb substrate. However, the highest temperature data indicate the early stages of the expected p to n type conversion which leads to apparent anomalously high carrier concentrations and lower than expected mobilities. Data at 77 K indicate very high quality buffer layers.

  17. Electrical properties of n-type GaSb substrates and p-type GaSb buffer layers for InAs/InGaSb superlattice infrared detectors

    Directory of Open Access Journals (Sweden)

    W. C. Mitchel

    2015-09-01

    Full Text Available Lightly doped n-type GaSb substrates with p-type GaSb buffer layers are the preferred templates for growth of InAs/InGaSb superlattices used in infrared detector applications because of relatively high infrared transmission and a close lattice match to the superlattices. We report here temperature dependent resistivity and Hall effect measurements of bare substrates and substrate-p-type buffer layer structures grown by molecular beam epitaxy. Multicarrier analysis of the resistivity and Hall coefficient data demonstrate that high temperature transport in the substrates is due to conduction in both the high mobility zone center Γ band and the low mobility off-center L band. High overall mobility values indicate the absence of close compensation and that improved infrared and transport properties were achieved by a reduction in intrinsic acceptor concentration. Standard transport measurements of the undoped buffer layers show p-type conduction up to 300 K indicating electrical isolation of the buffer layer from the lightly n-type GaSb substrate. However, the highest temperature data indicate the early stages of the expected p to n type conversion which leads to apparent anomalously high carrier concentrations and lower than expected mobilities. Data at 77 K indicate very high quality buffer layers.

  18. Electrical performances of pyroelectric bimetallic strip heat engines describing a Stirling cycle

    Science.gov (United States)

    Arnaud, A.; Boughaleb, J.; Monfray, S.; Boeuf, F.; Cugat, O.; Skotnicki, T.

    2015-12-01

    This paper deals with the analytical modeling of pyroelectric bimetallic strip heat engines. These devices are designed to exploit the snap-through of a thermo-mechanically bistable membrane to transform a part of the heat flowing through the membrane into mechanical energy and to convert it into electric energy by means of a piezoelectric layer deposited on the surface of the bistable membrane. In this paper, we describe the properties of these heat engines in the case when they complete a Stirling cycle, and we evaluate the performances (available energy, Carnot efficiency...) of these harvesters at the macro- and micro-scale.

  19. Study on the pyroelectric properties of lithium niobate wafer prepared by wafer bonding and thinning%铌酸锂晶片的键合减薄及热释电性能研究

    Institute of Scientific and Technical Information of China (English)

    杨绪军; 陈箫; 刘岗; 牛坤旺; 张文栋

    2011-01-01

    铌酸锂(LN)作为一种热释电材料,可以被用于制作光电探测器敏感单元的敏感层,但通常LN晶片厚度为0.5 mm,远大于光电敏感单元厚度的要求,所以需要用键合减薄及抛光技术对LN晶片进行加工处理.本研究所用键合减薄技术主要包含:RZJ-304光刻胶键合、铣磨、抛光、剥离液剥离和丙酮清洗RZJ-304胶.利用该技术加工得到了面积为10 mm×10 mm,厚度为50 μm,表面比较光滑,表面粗糙度为1.63 nm的LN晶片.LN晶片的热释电信号峰峰值在减薄抛光后为176 mV,是未经处理时的4倍,满足了热释电探测器敏感层的要求.%Pyroelectric material lithium niobate (LN) can be used for the preparation of sensitive layer in the sensitive element of photoelectric detector. However, as the thickness of normal LN wafer, which is 0.5 mm, is much larger than the thickness of sensitive element, LN wafer need to be processed using the thinning and polishing techniques. A novel wafer bonding and thinning technique was introduced in this study, and it mainly included: wafer bonding with RZJ-304 photoresist, grinding, polishing, separating wafers with stripper and removing photoresist with acetone. LN wafer (10mm in square) with a thickness of 50 um is prepared using this technique, and the surface of prepared LN wafer is very smooth with the surface roughness being 1.63 nm. The peak value of the pyroelectric signal of the processed LN wafer is 176 mV, which is four times that of the unprocessed wafer, fulfilling the requirements of the sensitive layer of pyroelectric detector.

  20. RTIA readout circuit for infrared focal plane array using active resistor%有源电阻RTIA红外焦平面读出电路

    Institute of Scientific and Technical Information of China (English)

    胡滨; 李威; 李平; 阙滨城

    2012-01-01

    提出了一种基于有源电阻的电阻反馈跨导放大器(RTIA)红外焦平面读出电路,该电路采用工作在亚阈区的MOS管实现1011Ω以上的有源大电阻,不仅能与热释电红外探测器的高阻抗良好匹配,而且配合两管共源放大器可针对热释电微弱信号进行高增益电流放大.同时,简单的三管单元结构能够方便地置于像元之下,相比于采用特殊高阻材料实现的RTIA,不附加材料和工艺.经上华0.5 μmCMOS工艺流片验证,在5V电源电压下,该电路增益40 dB,输出摆幅3V,在高低温测试下表现出了良好的增益带宽稳定性,适用于PZT和BST等热释电大阵列探测器.%A Resistive Trans-impedance Amplifier (RTIA) readout circuit for Uncooled Focal Plane Array (UFPA) using active resistor was proposed in this paper. By using a sub-threshold MOSFET as a 1011 Ω and above feedback resistor, a high gain current amplifier could be realized by common source structure which consisted of two transistors. The simple three transistors could be easily integrated under pixel and it had good impedance matching with pyroelectric infrared detector. Compared with traditional RTIAs which use special high-resistance materials as feedback resistor, the novel RTIA was low cost because no additional materials and processes were needed. The circuit was successfully manufactured by 0.5 μm standard CMOS process of CSMC foundry. 40 dB gain and 3 V output swing were realized by this design and the gain and bandwidth of the chip kept stable during high and low temperature tests. So it can be used for large arrays pyroelectric detectors such as Lead Zirconate Titanate (PZT) and Barium Strontium Titanate (BST), etc.

  1. Study on the Interface Effects Based on Two-Dimensional Green's Functions for the Fluid and Pyroelectric Two-Phase Plane under a Line Heat Source

    Directory of Open Access Journals (Sweden)

    Peng-Fei Hou

    2014-11-01

    Full Text Available Two-dimensional Green's functions for a line heat source applied in the fluid and pyroelectric two-phase plane are presented in this paper. By virtue of the two-dimensional general solutions which are expressed in harmonic functions, six newly introduced harmonic functions with undetermined constants are constructed. Then, all the pyroelectric components in the fluid and pyroelectric two-phase plane can be derived by substituting these harmonic functions into the corresponding general solutions. And the undetermined constants can be obtained by the interface compatibility conditions and the mechanical, electric, and thermal equilibrium conditions. Numerical results are given graphically by contours.

  2. Study on vacuum packaging of an uncooled infrared detector%一种非致冷红外探测器真空封装的研究

    Institute of Scientific and Technical Information of China (English)

    闫浩; 朱魁章; 仰叶

    2012-01-01

    A kind of packaging design of uncooled IR detector Dewar component was introduced in this paper. The key processes of packaging the detector at the condition of vacuum were analysed in detail. The factors which effects the vacuum life and the reliability of the component were described and resoved.%介绍了一种非致冷红外探测器杜瓦组件的封装设计;对探测器件在真空封装过程中的关键工艺技术进行了比较深入的分析;阐述了影响组件真空寿命及可靠性的因素以及解决措施.

  3. PtSi红外探测器截止波长延长研究%Study on Extension of Cut-off Wavelength of PtSi Infrared Detectors

    Institute of Scientific and Technical Information of China (English)

    刘爽; 杨家德; 刘飒; 宁永功; 陈艾

    2001-01-01

    The basic theory of the extension of cut-off wavelength of PtSi infrared detectors is discussed.Three methods are introduced including Tl+ and Ir+ doping, MBE growth of P+layer and B+, In+ low-energy ion-implantation.%讨论了将PtSi红外探测器截止波长延长的理论基础,并介绍了采用在衬底掺入Tl+和Ir+,MBE生长P+层以及低能离子注入B+,In+来延长PtSi红外探测器截止波长的三种方法。

  4. Demonstration of a non-contact x-ray source using an inductively heated pyroelectric accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Klopfer, Michael; Satchouk, Vladimir; Cao, Anh; Wolowiec, Thomas; Alivov, Yahya; Molloi, Sabee, E-mail: symolloi@uci.edu

    2015-04-11

    X-ray emission from pyroelectric sources can be produced through non-contact thermal cycling using induction heating. In this study, we demonstrated a proof of concept non-contact x-ray source powered via induction heating. An induction heater operating at 62.5 kHz provided a total of 6.5 W of delivered peak thermal power with 140 V DC of driving voltage. The heat was applied to a ferrous substrate mechanically coupled to a cubic 1 cm{sup 3} Lithium Niobate (LiNbO{sub 3}) pyroelectric crystal maintained in a 3–12 mTorr vacuum. The maximum temperature reached was 175 °C in 86 s of heating. The cooling cycle began immediately after heating and was provided by passive radiative cooling. The total combined cycle time was 250 s. x-ray photons were produced and analyzed in both heating and cooling phases. Maximum photon energies of 59 keV and 55 keV were observed during heating and cooling, respectively. Non-contact devices such as this, may find applications in cancer therapy (brachytherapy), non-destructive testing, medical imaging, and physics education fields.

  5. Development of ruthenium dioxide electrodes for pyroelectric devices based on lithium tantalate thin films

    Energy Technology Data Exchange (ETDEWEB)

    Nougaret, Laurianne [Centre d' Electronique et de Micro-optoelectronique de Montpellier, Unite mixte de Recherche du CNRS no 5507, Universite Montpellier II, Place E. Bataillon, 34095 Montpellier cedex 05 (France)]. E-mail: laurianne.nougaret@univ-montp2.fr; Combette, Philippe [Centre d' Electronique et de Micro-optoelectronique de Montpellier, Unite mixte de Recherche du CNRS no 5507, Universite Montpellier II, Place E. Bataillon, 34095 Montpellier cedex 05 (France)]. E-mail: philippe.combette@univ-montp2.fr; Arinero, Richard [Centre d' Electronique et de Micro-optoelectronique de Montpellier, Unite mixte de Recherche du CNRS no 5507, Universite Montpellier II, Place E. Bataillon, 34095 Montpellier cedex 05 (France)]. E-mail: richard.arinero@univ-montp2.fr; Podlecki, Jean [Centre d' Electronique et de Micro-optoelectronique de Montpellier, Unite mixte de Recherche du CNRS no 5507, Universite Montpellier II, Place E. Bataillon, 34095 Montpellier cedex 05 (France)]. E-mail: jean.podlecki@univ-montp2.fr; Pascal-Delannoy, Frederique [Centre d' Electronique et de Micro-optoelectronique de Montpellier, Unite mixte de Recherche du CNRS no 5507, Universite Montpellier II, Place E. Bataillon, 34095 Montpellier cedex 05 (France)]. E-mail: Frederique.delannoy@univ-montp2.fr

    2007-02-26

    The aim of this paper is the study of ruthenium dioxide (RuO{sub 2}) films, grown on low-stress silicon nitride on silicon (SiN {sub x}/Si), in order to develop thermal micro-sensors based on pyroelectric effect. The active part of these micro-sensors is constituted by a new arrangement : lithium tantalate (LiTaO{sub 3})/RuO{sub 2}/SiN{sub x}/Si. Radio-frequency (RF) sputtering is employed to deposit RuO{sub 2} on SiN {sub x}/Si substrate. Morphology, crystallinity and resistivity of RuO{sub 2} are studied as function of growth parameters. Next, RF magnetron sputtering was used to deposit LiTaO{sub 3} on this electrode. Morphology studies, pyroelectric effect and dielectric parameters obtained, indicate that RuO{sub 2} material is a suitable candidate as back electrode for LiTaO{sub 3} thin films.

  6. Flexible Polymer-on-Polymer Architecture for Piezo/Pyroelectric Energy Harvesting.

    Science.gov (United States)

    Talemi, Pejman; Delaigue, Marine; Murphy, Peter; Fabretto, Manrico

    2015-04-29

    An all polymer piezo/pyroelectric device was fabricated using β phase poly(vinylidene fluoride) (PVDF) as the active material and vapor phase polymerized (VPP) poly(3,4-ethylenedioxythiphene) (PEDOT) as the flexible electrode overlay material. Inherent problems usually associated with coating polymeric electrodes onto the low surface energy PVDF were overcome by air plasma treating the film in conjunction with utilizing the VPP technique to simultaneously synthesize and in situ deposit the PEDOT electrode. Strain measurements up to the breaking-strain of PVDF (approximately 35%) indicated that the change in R/Ro was significantly smaller for the PEDOT based electrodes compared to the platinum electrode. Plasma treatment of the PVDF film increased the level of surface oxygenated carbon species that contributed to increased surface energy, as confirmed by confirmed by contact angle measurement. The enhanced adhesion between the two polymers layers contributed to a significant increase in the measured piezoelectric output voltage from 0.2 to 0.5 V for the same strain conditions. Pyroelectric voltage outputs were obtained by placing the film onto and off of a hotplate, for temperatures up to 50 °C above ambient. Finally, as a proof of concept, a simple energy harvesting device (plastic tube with slots for mounting multiple piezo/pyro films) was fabricated. The device was able to generate a usable level of peak output current (>3.5 μA) from human inhalation and exhalation "waste energy".

  7. An Analysis about the Factors Affecting Working Life of Infrared Detector%红外探测器工作寿命的影响因素分析

    Institute of Scientific and Technical Information of China (English)

    崔军生; 贾卫民

    2011-01-01

    某系统上使用了几年的探测器在随系统返修测试的过程中,发现其斯特林制冷机在连续工作一段时间后突然停机,重新启动制冷器后降温速率变慢且探测器内部温度只能降到90K左右。本文针对杜瓦漏热和制冷功率因素与探测器工作寿命的影响关系进行了分析,得出了一些对提高探测器寿命具有帮助意义的结论。%In the repair testing process of the system after working many years, it is found that the Stirling cryocooler stops working suddenly after continuous running for a period of time. The cooling speed rate becomes slow and the minimum internal temperature of the detector only reaches about 90 K after restarting the Stirling cryocooler. The influence of Dewar thermal leakage and cooling power on the working life of detector is discussed. The conclusions are useful for improving the working life of detector.

  8. Very high-gain and low-excess noise near-infrared single-photon avalanche detector: an NIR solid state photomultiplier

    Science.gov (United States)

    Linga, Krishna; Yevtukhov, Yuriy; Liang, Bing

    2009-05-01

    A new family of photodetectors with a Discrete Amplification (DA) mechanism allows the realization of very high gain and low excess noise factor in the visible and near infrared spectral regions and offers an alternative to conventional photomultiplier tubes and Geiger mode avalanche photodetectors. These photodetectors can operate in linear detection mode with gain-bandwidth product in excess of 4X1014 and in photon counting mode with count rates up to 108 counts/sec. Potential benefits of this technology over conventional avalanche photodetectors include ultra low excess noise factor, very high gain, and lower reset time (photodetectors in the near infrared wavelength range. The measured devices have the following performance characteristics: gain > 2X105, excess noise factor Lidar, quantum cryptography, night vision and other military, defence and aerospace applications.

  9. Modelling of current-voltage characteristics of infrared photo-detectors based on type – II InAs/GaSb super-lattice diodes with unipolar blocking layers

    Directory of Open Access Journals (Sweden)

    Vishnu Gopal

    2015-09-01

    Full Text Available It is shown that current-voltage characteristics of infrared photo-detectors based on type-II InAs/GaSb super-lattices with uni-polar blocking layers can be modelled similar to a junction diode with a finite series resistance on account of blocking barriers. As an example this paper presents the results of a study of current-voltage characteristics of a type II InAs/GaSb super-lattice diode with PbIbN architecture using a recently proposed [J. Appl. Phys. 116, 084502 (2014] method for modelling of illuminated photovoltaic detectors. The thermal diffusion, generation – recombination (g-r, and ohmic currents are found as principal components besides a component of photocurrent due to background illumination. The experimentally observed reverse bias diode current in excess of thermal current (diffusion + g-r, photo-current and ohmic shunt current is reported to be best described by an exponential function of the type, Iexcess = Ir0 + K1exp(K2 V, where Ir0, K1 and K2 are fitting parameters and V is the applied bias voltage. The present investigations suggest that the exponential growth of excess current with the applied bias voltage may be taking place along the localized regions in the diode. These localized regions are the shunt resistance paths on account of the surface leakage currents and/or defects and dislocations in the base of the diode.

  10. MSM-Metal Semiconductor Metal Photo-detector Using Black Silicon Germanium (SiGe) for Extended Wavelength Near Infrared Detection

    Science.gov (United States)

    2012-09-01

    they produced that microstructure using only halogenated etching gas (sulfur hexafluoride [ SF6 ]), the spectral absorbance of light was extended well...infrared imaging. In 2003, Mazur and colleagues reported that using femtosecond laser processing coupled with halogenated etching gas could produce...metal-masked, wet-chemical etching approach versus a femtosecond gas -phase etching process, and (2) we used in-situ boron doping p≈5x10 19 /cm 3

  11. Preparation and Characterization of BaTiO3-PbZrTiO3 Coating for Pyroelectric Energy Harvesting

    Science.gov (United States)

    Raghavendra, R. M.; Praneeth, K. P. S. S.; Dutta, Soma

    2016-08-01

    Harvesting energy from waste heat is a promising field of research as there are significant energy recovery opportunities from various waste thermal energy sources. The present study reports pyroelectric energy harvesting using thick film prepared from a (x)BaTiO3-(1 - x)PbZr0.52Ti0.48O3 (BT-PZT) solid solution. The developed BT-PZT system is engineered to tune the ferro to paraelectric phase transition temperature of it in-between the phase transition temperature of BaTiO3 (393 K) and PbZrTiO3 (573 K) with higher pyroelectric figure-of-merit (FOM). The temperature-dependent dielectric behavior of the material has revealed the ferro- to paraelectric phase transition at 427 K with a maximum dielectric constant of 755. The room-temperature (298 K) pyroelectric coefficient (Pi) of the material was obtained as 738.63 μC/m2K which has yielded a significantly high FOM of 1745.8 J m-3 K-2. The enhancement in pyroelectric property is attributed to the morphotopic phase transition between tetragonal and rhombohedral PZT phases in the BT-PZT system. The developed BT-PZT system is capable of generating a power output of 1.3 mW/m2 near the Curie temperature with a constant rate (0.11 K/s) of heating. A signal conditioning circuit has been developed to rectify the time-varying current and voltage signals obtained from the harvester during heating cycles. The output voltage generated by the pyroelectric harvester has been stored in a capacitor for powering wearable electronics.

  12. Preparation and Characterization of BaTiO3-PbZrTiO3 Coating for Pyroelectric Energy Harvesting

    Science.gov (United States)

    Raghavendra, R. M.; Praneeth, K. P. S. S.; Dutta, Soma

    2017-01-01

    Harvesting energy from waste heat is a promising field of research as there are significant energy recovery opportunities from various waste thermal energy sources. The present study reports pyroelectric energy harvesting using thick film prepared from a (x)BaTiO3-(1 - x)PbZr0.52Ti0.48O3 (BT-PZT) solid solution. The developed BT-PZT system is engineered to tune the ferro to paraelectric phase transition temperature of it in-between the phase transition temperature of BaTiO3 (393 K) and PbZrTiO3 (573 K) with higher pyroelectric figure-of-merit (FOM). The temperature-dependent dielectric behavior of the material has revealed the ferro- to paraelectric phase transition at 427 K with a maximum dielectric constant of 755. The room-temperature (298 K) pyroelectric coefficient (Pi) of the material was obtained as 738.63 μC/m2K which has yielded a significantly high FOM of 1745.8 J m-3 K-2. The enhancement in pyroelectric property is attributed to the morphotopic phase transition between tetragonal and rhombohedral PZT phases in the BT-PZT system. The developed BT-PZT system is capable of generating a power output of 1.3 mW/m2 near the Curie temperature with a constant rate (0.11 K/s) of heating. A signal conditioning circuit has been developed to rectify the time-varying current and voltage signals obtained from the harvester during heating cycles. The output voltage generated by the pyroelectric harvester has been stored in a capacitor for powering wearable electronics.

  13. Infrared retina

    Science.gov (United States)

    Krishna, Sanjay; Hayat, Majeed M.; Tyo, J. Scott; Jang, Woo-Yong

    2011-12-06

    Exemplary embodiments provide an infrared (IR) retinal system and method for making and using the IR retinal system. The IR retinal system can include adaptive sensor elements, whose properties including, e.g., spectral response, signal-to-noise ratio, polarization, or amplitude can be tailored at pixel level by changing the applied bias voltage across the detector. "Color" imagery can be obtained from the IR retinal system by using a single focal plane array. The IR sensor elements can be spectrally, spatially and temporally adaptive using quantum-confined transitions in nanoscale quantum dots. The IR sensor elements can be used as building blocks of an infrared retina, similar to cones of human retina, and can be designed to work in the long-wave infrared portion of the electromagnetic spectrum ranging from about 8 .mu.m to about 12 .mu.m as well as the mid-wave portion ranging from about 3 .mu.m to about 5 .mu.m.

  14. A Long Wave Infrared (LWIR) spectral imager (7.7 to 12.3 μ) based on cooled detector array and high resolution Circular Variable Filter (CVF)

    Science.gov (United States)

    Cabib, Dario; Lavi, Moshe; Gil, Amir; Ohel, Eran; Dolev, Jacob; Milman, Uri

    2013-10-01

    Spectral imagers in the Long Wave IR spectral range (8 to 12 microns) suffer from the problem of high production costs because the existing commercial cooled array detectors are expensive, and in fact they are prohibitively expensive for many applications. As a result, the drive to lower the cost of Long Wave IR spectral imagers is strong: this is the main motivation for CI to investigate a new design that allows these spectral imagers to be more affordable. One area of possible cost reduction without relinquishing the advantages of a cryogenically cooled detector is the method used to provide the spectral information. CI Systems has developed a long wave IR (7.7 to 12.3 micron) spectral imager concept using a Circular Variable Filter (CVF), (a proprietary component based on multiple layer interference filter technology) which has advantages over the interferometric Fourier Transform method commonly used in this spectral range. The CVF method has its own development challenges; however, once proven, this concept may be more suitable and affordable for applications in which a spectral resolution of 0.5% of the wavelength (or 50 nm at 10 μ) is required. The design of the optical system must minimize background signals without being cooled to cryogenic temperatures, so we called it VIrtually COld (or VICO). CI is in the final stages of prototype building and characterization. Present initial calibration results and measurement examples are given in this paper.

  15. Advanced methods for preparation and characterization of infrared detector materials. [crystallization and phase diagrams of Hg sub 1-x Cd sub x Te

    Science.gov (United States)

    Lehoczy, S. L.

    1979-01-01

    Crystal growth of Hg sub 1-x Cd sub x Te and density measurements of ingot slices are discussed. Radial compositional variations are evaluated from the results of infrared transmission edge mapping. The pseudo-binary HgTe-CdTe phase diagram is examined with reference to differential thermal analysis measurements. The phase equilibria calculations, based on the 'regular association solution' theory (R.A.S.) are explained and, using the obtained R.A.S. parameters, the activities of Hg, Cd, and Te vapors and their partial pressures over the pseudo-binary melt are calculated.

  16. Dynamic pyroelectric response of composite based on ferroelectric copolymer of poly(vinylidene fluoride-trifluoroethylene) and ferroelectric ceramics of barium lead zirconate titanate

    Energy Technology Data Exchange (ETDEWEB)

    Solnyshkin, A.V. [Tver State University, Department of Condensed Matter Physics, Tver (Russian Federation); National Research University ' ' MIET' ' , Department of Intellectual Technical Systems, Zelenograd, Moscow (Russian Federation); Morsakov, I.M.; Bogomolov, A.A. [Tver State University, Department of Condensed Matter Physics, Tver (Russian Federation); Belov, A.N.; Vorobiev, M.I.; Shevyakov, V.I.; Silibin, M.V. [National Research University ' ' MIET' ' , Department of Intellectual Technical Systems, Zelenograd, Moscow (Russian Federation); Shvartsman, V.V. [University of Duisburg-Essen, Institute for Materials Science, Essen (Germany)

    2015-10-15

    In this work, pyroelectric properties of composite films on the basis of poly(vinylidene fluoride-trifluoroethylene) copolymer with a various level of ferroelectric ceramics inclusions of barium lead zirconate titanate solid solution were investigated by the dynamic method. The composite films were prepared by the solvent cast method. The unusual spike-like dynamic response with a quasi-stationary component was observed. It is supposed that composite films may be effectively used for pyroelectric applications. (orig.)

  17. Development of Strained-Layer Superlattice (SLS) IR Detector Camera Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Strained Layer Superlattice (SLS) detectors are a new class of detectors.   In our FY12 IRAD “Strained Layer Superlattice Infrared Detector Array...

  18. QUANTUM MECHANICAL MODEL AND SIMULATION OF GaAs/AlGaAs QUANTUM WELL INFRARED PHOTO-DETECTOR-Ⅰ OPTICAL ASPECTS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A complete quantum mechanical model for GaAs/AlGaAs quantum well infrared photodetectors(QWIPs) is presented here. The model consisted of four parts: (1) Starting with the description of the electromagnetic field of the infrared radiation in the QWIP, effective component of the vector potential 〈|Az|〉 along the QWIP growth direction (z-axis) due to the optical diffraction grating was calculated. (2) From the wave transmissions and the occupations of the electronic states, it was discussed that the dark current in the QWIP is determined by the drift-diffusion current of carriers thermally excited from the ground sublevel in the quantum well to extended states above the barrier. (3) The photocurrent was investigated by the optical transition (absorption coefficient between the ground state to excited states due to the nonzero-〈|Az|〉 ). (4) By studying the inter-diffusion of the Al atoms across the GaAs/AlGaAs heterointerfaces,the mobility of the drift-diffusion carriers in the excited states was calculated, so the measurement results of the dark current and photocurrent spectra can be explained theoretically. With the complete quantum mechanical descriptions of (1-4), QWIP device design and optimization are possible.

  19. Optical properties of D-serine doped TGS crystals for pyroelectric sensors*

    Directory of Open Access Journals (Sweden)

    Kurlyak V.Yu.

    2015-12-01

    Full Text Available Refractive and birefringence indices in the range of transparency of 300 to 700 nm for triglycine sulphate crystals doped with D-serine molecules have been measured in the temperature range of 290 K to 340 K. The obtained optical properties are discussed together with characteristic electrical features of these materials used as pyroelectric sensors for measurement of temperature. The experimental results obtained in this study will be necessary as the reference data for comparison with the calculated refractive indices of TGS + D-serine on the basis of density functional theory. Determination of the proper position of D-serine, will reveal the features of TGS + D-serine crystal structure necessary to achieve stable unipolarity.

  20. Pyroelectric properties and conduction mechanism in solution grown glycine sodium nitrate single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Nidhi [Crystal Lab, Department of Physics & Astrophysics, University of Delhi, Delhi 7 (India); Sinha, Nidhi [Crystal Lab, Department of Physics & Astrophysics, University of Delhi, Delhi 7 (India); Department of Electronics, SGTB Khalsa College, University of Delhi, Delhi 7 (India); Yadav, Harsh [Crystal Lab, Department of Physics & Astrophysics, University of Delhi, Delhi 7 (India); Kumar, Binay, E-mail: b3kumar69@yahoo.co.in [Crystal Lab, Department of Physics & Astrophysics, University of Delhi, Delhi 7 (India)

    2015-04-01

    Nonlinear optical “glycine sodium nitrate” transparent single crystals were grown from aqueous solution by the solvent evaporation technique. The ferroelectric transition temperature was determined by dielectric measurement for GSN crystal. Temperature dependent pyroelectric coefficient and figure of merit were measured. The conduction mechanism of GSN crystal has been discussed. The ln σ−E{sup 1/2} characteristic in the high-field region supports dominating the Poole–Frenkel conduction while in the low field region; there are possibility of both Richardson–Schottky and Poole–Frenkel conduction mechanism. The activation energy of GSN crystal was found to be 0.58 eV. A low value of dielectric constant and good value of the figure of merit suggest the GSN crystal more promising for IR sensing applications. Hardness value shows the stability of GSN crystal.

  1. Scanning thermal microscopy based on a modified atomic force microscope combined with pyroelectric detection

    Science.gov (United States)

    Antoniow, J.-S.; Chirtoc, M.; Trannoy, N.; Raphael, O.; Pelzl, J.

    2005-06-01

    We propose a novel approach in scanning thermal microscopy of layered samples. The thermal probe (ThP) (Wollaston wire) acts as a local a.c. heat source at the front of a sample layer deposited on a pyroelectric (PE) sensor. The PE signal is proportional to the heat wave transmitted through the sample. The ThP and PE signals can be used to generate complementary thermal conductivity maps and with some restrictions, thermal diffusivity maps of the sample. Additionally, the topography map is obtained in the usual way from the atomic force microscope. We give the theoretical background for the interpretation of PE signal obtained at low and at high frequency, and we demonstrate that it carries information on the thermal diffusivity of a test sample (12 μm thick PET polymer sheet). Finally, we discuss the contributions of heat transfer channels between ThP and sample, and the role of contact thermal resistance.

  2. PLZT ferroelectric ceramics on the morphotropic boundary phase. Study as possible pyroelectric sensors

    Energy Technology Data Exchange (ETDEWEB)

    Pelaiz Barranco, A.; Perez Martinez, O. [Univ. de La Habana (Cuba). Inst. de Materiales y Reactivos; Calderon Pinar, F. [Univ. de La Habana (Cuba). Inst. de Materiales y Reactivos; Centro de Investigaciones en Ciencia Aplicada y Tecnologia de Avanzada (CICATA), Altamira, Tamps (Mexico)

    2001-08-16

    PLZT compositions near the morphotropic boundary phase (Zr/Ti = 53/47) were studied changing the lanthanum fraction from 0.5 to 14 at%. The grain size and the porosity due to the lanthanum addition showed an important influence on the dielectric properties of the samples. Dielectric and pyroelectric studies show that the ceramics of lower lanthanum concentrations are suitable materials for practical applications. The ceramic's response subjected to light radiation was investigated. The radiation is absorbed near the material surface and its temperature rises leading to a change in the electrical polarization of the bulk material. This phenomenon is analyzed and correlated with the absorbed light on the surface of the material. (orig.)

  3. Preparation of room temperature terahertz detector with lithium tantalate crystal and thin film

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun, E-mail: ueoewj@gmail.com; Gou, Jun; Li, Weizhi [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2014-02-15

    Research on room temperature terahertz (THz) detector is essential for promoting the application of THz science and technology. Both lithium tantalate crystal (LiTaO{sub 3}) and lithium tantalate thin film were used to fabricate the THz detector in this paper. Polishing process were used to reduce the thickness of LiTaO{sub 3} crystal slice by chemical mechanical polishing techniques and an improved sol-gel process was used to obtain high concentration LiTaO{sub 3} precursor solution to fabricate LiTaO{sub 3} thin film. Three dimension models of two THz detectors were set up and the temperature increasing map of two devices were simulated using finite element method. The lowest noise equivalent power value for terahertz detector using pyroelectric material reaches 6.8 × 10{sup −9} W at 30 Hz operating frequency, which is suitable for THz imaging application.

  4. Preparation of room temperature terahertz detector with lithium tantalate crystal and thin film

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2014-02-01

    Full Text Available Research on room temperature terahertz (THz detector is essential for promoting the application of THz science and technology. Both lithium tantalate crystal (LiTaO3 and lithium tantalate thin film were used to fabricate the THz detector in this paper. Polishing process were used to reduce the thickness of LiTaO3 crystal slice by chemical mechanical polishing techniques and an improved sol-gel process was used to obtain high concentration LiTaO3 precursor solution to fabricate LiTaO3 thin film. Three dimension models of two THz detectors were set up and the temperature increasing map of two devices were simulated using finite element method. The lowest noise equivalent power value for terahertz detector using pyroelectric material reaches 6.8 × 10−9 W at 30 Hz operating frequency, which is suitable for THz imaging application.

  5. Piezoelectric and pyroelectric properties of Sr-doped PZT (PSZT) with minor manganese additions

    Science.gov (United States)

    Aleem, M. A.; Nawaz, H.; Shuaib, M.; Qaisar, S.; Akbar, M. S.

    2013-06-01

    A systematic study was performed to see the effect of Manganese addition and temperature gradient on the electrical properties of PSZT. Pb0.96 Sr0.04 (Zr0.52Ti0.48) O3 (PSZT) containing 0.3%, 0.5%, and 1% Mn was prepared by the sol gel method in order to ensure good stoichiometry and enhanced purity. The powders were calcined at 550 °C and sintered at 1200 °C to achieve 98% of the theoretical density. High field ac study was performed by (P-E) hysteresis measurements at different temperatures (RT, 60, 90, 120 and 150 °C) using an electric field up to 3 kV/mm. It was observed that for a lower Mn concentration P-E loops are pinched at the center while this constriction is found to decrease for greater concentrations. The optimized results were obtained for the 1 mol% of Mn content with 4 mol% of Sr. The values of Qm, k, d33 and tanδ were measured as 756, 0.38, 257 and 0.002 respectively. Higher temperatures coupled with a gradual increase of the electric field resulted in a shift of the hysteresis loops along electric field axis, indicating the presence of an internal bias field. Dependence of pyroelectric properties on applied electric field was also investigated. The value of pyroelectric coefficient was found maximum 6.25 × 10-4 (C/m2K) at 3 kV/mm.

  6. Detector Unit

    CERN Multimedia

    1960-01-01

    Original detector unit of the Instituut voor Kernfysisch Onderzoek (IKO) BOL project. This detector unit shows that silicon detectors for nuclear physics particle detection were already developed and in use in the 1960's in Amsterdam. Also the idea of putting 'strips' onto the silicon for high spatial resolution of a particle's impact on the detector were implemented in the BOL project which used 64 of these detector units. The IKO BOL project with its silicon particle detectors was designed, built and operated from 1965 to roughly 1977. Detector Unit of the BOL project: These detectors, notably the ‘checkerboard detector’, were developed during the years 1964-1968 in Amsterdam, The Netherlands, by the Natuurkundig Laboratorium of the N.V. Philips Gloeilampen Fabrieken. This was done in close collaboration with the Instituut voor Kernfysisch Onderzoek (IKO) where the read-out electronics for their use in the BOL Project was developed and produced.

  7. Determination of charge-carrier diffusion length in the photosensing layer of HgCdTe n-on-p photovoltaic infrared focal plane array detectors

    Energy Technology Data Exchange (ETDEWEB)

    Vishnyakov, A. V.; Stuchinsky, V. A., E-mail: stuchin@isp.nsc.ru; Brunev, D. V.; Zverev, A. V.; Dvoretsky, S. A. [Institute of Semiconductor Physics, Russian Academy of Science, Siberian Division, 13, Acad. Lavrent' ev Avenue, Novosibirsk 630090 (Russian Federation)

    2014-03-03

    In the present paper, we propose a method for evaluating the bulk diffusion length of minority charge carriers in the photosensing layer of photovoltaic focal plane array (FPA) photodetectors. The method is based on scanning a strip-shaped illumination spot with one of the detector diodes at a low level of photocurrents j{sub ph} being registered; such scanning provides data for subsequent analysis of measured spot-scan profiles within a simple diffusion model. The asymptotic behavior of the effective (at j{sub ph} ≠ 0) charge-carrier diffusion length l{sub d} {sub eff} as a function of j{sub ph} for j{sub ph} → 0 inferred from our experimental data proved to be consistent with the behavior of l{sub d} {sub eff} vs j{sub ph} as predicted by the model, while the obtained values of the bulk diffusion length of minority carriers (electrons) in the p-HgCdTe film of investigated HgCdTe n-on-p FPA photodetectors were found to be in a good agreement with the previously reported carrier diffusion-length values for HgCdTe.

  8. A numerical investigation on exergy analyses of a pyroelectric tryglycine sulfate (TGS)-based solar energy harvesting system

    Science.gov (United States)

    Sharma, Manish; Vaish, Rahul; Singh Chauhan, Vishal

    2016-02-01

    This study is based on a numerical demonstration of energy and exergy analyses of a solar energy harvesting system based on the pyroelectric effect. The performance of a tryglycine sulfate (TGS) single crystal was investigated mathematically in the present study. The power output was optimized for different load resistances and load capacitances. The maximum power output was obtained as 0.95 μW across a load resistance of 40 MΩ and a 4.7 μF load capacitor. Further exergy analysis was performed for a pyroelectric energy harvesting system. Maximum values for electrical and thermal exergies obtained are 0.12 μW and 12 mW, respectively. Furthermore the maximum obtained electrical and thermal exergy efficiencies are 0.000 037% and 3.6%, respectively. The average thermal exergy efficiency is 2.15% for a cycle frequency of 0.014 Hz.

  9. Real-time continuous-wave imaging with a 1.63THz OPTL and a pyroelectric camera

    Institute of Scientific and Technical Information of China (English)

    YANG Jun; RUAN Shuang-chen; ZHANG Min; ZHANG Wei

    2008-01-01

    Real-time continuous-wave terahertz imaging is demonstrated with a 1.63 THz (184.31 μm) optically-pumped terahertz laser (OPTL) and a 124 × 124 element room-temperature pyroelectric camera. Transmission-mode THz imaging is presented for the samples hidden in various wrapping materials. These experimental results reveal the possibility to construct a simple real-time THz imaging system applied to nondestructive inspection.

  10. Pyroelectric and electrocaloric effect of <1 1 1>-oriented 0.9PMN-0.1PT single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Luo Laihui, E-mail: llhsic@126.com [Department of Physics, Ningbo University, Ningbo 315211 (China); Chen Hongbing [Institute of Materials Science and Engineering, Ningbo University, Ningbo 315211 (China); Zhu Yuejin; Li Weiping [Department of Physics, Ningbo University, Ningbo 315211 (China); Luo Haosu [Shanghai Institute of ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Zhang Yuepin [Department of Physics, Ningbo University, Ningbo 315211 (China)

    2011-08-11

    Highlights: > Here, we use indirect method to measure pyroelectric and electrocaloric effect. > The largest temperature change achieves {approx}1 deg. C with a small field change. > The mechanism of electrocaloric effect of PMN-PT is explained. > The largest ({partial_derivative}P/{partial_derivative}T){sub E} value achieves -0.5 {mu}C/cm{sup 2} K. > PMN-PT has excellent pyroelectric effect. - Abstract: In this paper, the polarization vs. electric field hysteresis loops of <1 1 1>-oriented 0.9PbMg{sub 1/3}Nb{sub 2/3}O{sub 3}-0.1PbTiO{sub 3} (0.9PMN-0.1PT) single crystal at different temperatures (20-110 deg. C) were measured. The adiabatic temperature change {Delta}T of <1 1 1>-oriented 0.9PMN-0.1PT single crystal due to the application or withdraw of electric field were calculated through the thermodynamic relation. The largest temperature change {Delta}T achieves {approx}1 K with only a change of 40 kV/cm electric field, the mechanism of the electrocaloric effect (ECE) is discussed for 0.9PMN-0.1PT crystal. The pyroelectric coefficient of 0.9PMN-0.1PT under bias field was calculated according to the data of hysteresis loop. The result shows that 0.9PMN-0.1PT have large pyroelectric coefficient under bias field, the largest ({partial_derivative}P/{partial_derivative}T){sub E} value achieves -0.5 {mu}C/cm{sup 2} K.

  11. Ionization Mechanism of the Ambient Pressure Pyroelectric Ion Source (APPIS) and Its Applications to Chemical Nerve Agent Detection

    OpenAIRE

    Neidholdt, Evan L.; Beauchamp, J. L.

    2009-01-01

    We present studies of the ionization mechanism operative in the ambient pressure pyroelectric ionization source (APPIS), along with applications that include detection of simulants for chemical nerve agents. It is found that ionization by APPIS occurs in the gas-phase. As the crystal is thermally cycled over a narrow temperature range, electrical discharges near the surface of the crystal produce energetic species which, through reactions with atmospheric molecules, result in reactant ions su...

  12. Investigation of the effect of noise on the operation of the charge sensitive amplifier with compensated pyroelectric interference

    Directory of Open Access Journals (Sweden)

    Starcev V. I.

    2015-08-01

    Full Text Available The authors consider the problems that arise during the operation of the charge sensitive amplifier (CSA in critical conditions. Simplified schemes and mathematical models of the CSA are presented in order to study the effect of noise of operational amplifier and high-resistance resistor of negative feedback loop. The dependence of the CSA noise level on the pyroelectric interference compensation value is studied. Mathematical analysis data is confirmed by computer circuit simulation.

  13. Infrared landmine detection and thermal model analysis

    NARCIS (Netherlands)

    Schwering, P.B.W.; Kokonozi, A.; Carter, L.J.; Lensen, H.A.; Franken, E.M.

    2001-01-01

    Infrared imagers are capable of the detection of surface laid mines. Several sensor fused land mine detection systems make use of metal detectors, ground penetrating radar and infrared imagers. Infrared detection systems are sensitive to apparent temperature contrasts and their detection capabilitie

  14. Gaseous Detectors: Charged Particle Detectors - Particle Detectors and Detector Systems

    CERN Document Server

    Hilke, H J

    2011-01-01

    Gaseous Detectors in 'Charged Particle Detectors - Particle Detectors and Detector Systems', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Subsection '3.1.2 Gaseous Detectors' of Section '3.1 Charged Particle Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.1.2 Gaseous Detectors 3.1.2.1 Introduction 3.1.2.2 Basic Processes 3.1.2.2.1 Gas ionization by charged particles 3.1.2.2.1.1 Primary clusters 3.1.2.2.1.2 Cluster size distribution 3.1.2.2.1.3 Total number of ion pairs 3.1.2.2.1.4 Dependence of energy deposit on particle velocity 3.1.2.2.2 Transport of...

  15. Effect of atmospheric turbulence on the bit error probability of a space to ground near infrared laser communications link using binary pulse position modulation and an avalanche photodiode detector

    Science.gov (United States)

    Safren, H. G.

    1987-01-01

    The effect of atmospheric turbulence on the bit error rate of a space-to-ground near infrared laser communications link is investigated, for a link using binary pulse position modulation and an avalanche photodiode detector. Formulas are presented for the mean and variance of the bit error rate as a function of signal strength. Because these formulas require numerical integration, they are of limited practical use. Approximate formulas are derived which are easy to compute and sufficiently accurate for system feasibility studies, as shown by numerical comparison with the exact formulas. A very simple formula is derived for the bit error rate as a function of signal strength, which requires only the evaluation of an error function. It is shown by numerical calculations that, for realistic values of the system parameters, the increase in the bit error rate due to turbulence does not exceed about thirty percent for signal strengths of four hundred photons per bit or less. The increase in signal strength required to maintain an error rate of one in 10 million is about one or two tenths of a db.

  16. Mid-wavelength infrared InAs/GaSb type Ⅱ superlattice detectors%InAs/GaSb Ⅱ类超晶格中波红外探测器

    Institute of Scientific and Technical Information of China (English)

    徐庆庆; 陈建新; 周易; 李天兴; 金巨鹏; 林春; 何力

    2012-01-01

    Infrared (IR) photo detectors based on InAs/GaSb type II superlattice have developed quickly in recent years. Many groups show great interest in InAs/GaSb superlattice detector for its superiors as high quantum efficient, high working temperature, high uniformity and low dark current densities. The growth of mid-wavelength infrared InAs/GaSb superlattice on GaSb substrates by molecular beam epitaxy (MBE) was studied. The growth temperature and the interface structures to obtain high quality material were optimized. The InAs/GaSb superlattice layers were characterized by atomic force microscope(AFM) and high resolution X-ray diffraction (XRD). Finally, highly lattice matched mid-infrared InAs/GaSb superlattice material was achieved. The FWHM of the Oth satellite peak of X-ray scanning curve is 28.8 arcsec. The p-I-n single IR photodiode based on InAs/GaSb superlattice has current responsivity of 0.48 A/W and blackbody detectivity of 4.54xl010 cmHz1/2W, and peak detectivity of 1.75x1011 cmHz1/2W at 77 K.%InAs/GaSbⅡ类超晶格探测器是近年来国际上发展迅速的红外探测器,其优越性表现在高量子效率和高工作温度,以及良好的均匀性和较低的暗电流密度,因而受到广泛关注.报道了InAs/GaSb超晶格中波材料的分子束外延生长和器件性能.通过优化分子束外延生长工艺,包括生长温度和快门顺序等,获得了具原子级表面平整的中波InAs/GaSb超晶格材料,X射线衍射零级峰的双晶半峰宽为28.8″,晶格失配△a/a=1.5×10-4.研制的p-i-n单元探测器在77 K温度下电流响应率达到0.48 A/W,黑体探测率为4.54×1010 cmHz1/2W,峰值探测率达到1.75×1011cmHz1/2W.

  17. Doped carbon nanostructure field emitter arrays for infrared imaging

    Science.gov (United States)

    Korsah, Kofi [Knoxville, TN; Baylor, Larry R [Farragut, TN; Caughman, John B [Oak Ridge, TN; Kisner, Roger A [Knoxville, TN; Rack, Philip D [Knoxville, TN; Ivanov, Ilia N [Knoxville, TN

    2009-10-27

    An infrared imaging device and method for making infrared detector(s) having at least one anode, at least one cathode with a substrate electrically connected to a plurality of doped carbon nanostructures; and bias circuitry for applying an electric field between the anode and the cathode such that when infrared photons are adsorbed by the nanostructures the emitted field current is modulated. The detectors can be doped with cesium to lower the work function.

  18. Characterisation and Modelling of Meshed Electrodes on Free Standing Polyvilylidene Difluoride (PVDF) Films for Enhanced Pyroelectric Energy Harvesting.

    Science.gov (United States)

    Zabek, Daniel; Taylor, John; Bowen, Chris

    2016-09-05

    Flexible pyroelectric energy generators provide unique features for harvesting temperature fluctuations which can be effectively enhanced using meshed electrodes that improve thermal conduction, convection and radiation into the pyroelectric. In this paper, thermal radiation energy is continuously harvested with pyroelectric free standing Polyvilylidene Difluoride (PVDF) films over a large number of heat heat cycles using a novel micro-sized symmetrical patterned meshed electrode. It is shown that, for the meshed electrode geometries considered in this work, the polarisation-field (P-E), current-field (I-E) characteristics and device capacitance are unaffected since the fringing fields were generally small; this is verified using numerical simulations and comparison with experimental measurements. The use of meshed electrodes has been shown to significantly improve both the open circuit voltage (16 V to 59 V) and closed-circuit current (9 nA to 32 nA). The pyroelectric alternating current (AC) is rectified for direct current (DC) storage and 30% reduction in capacitor charging time is achieved by using the optimum meshed electrodes. The use of meshed electrodes on ferroelectric materials provides an innovative route to improve their performance in applications such as wearable devices, novel flexible sensors and large scale pyroelectric energy harvesters.hese instructions give you guidelines for preparing papers for IEEE Transactions and Journals. Use this document as a template if you are using Microsoft Word 6.0 or later. Otherwise, use this document as an instruction set. The electronic file of your paper will be formatted further at IEEE. Paper titles should be written in uppercase and lowercase letters, not all uppercase. Avoid writing long formulas with subscripts in the title; short formulas that identify the elements are fine (e.g., "Nd-Fe-B"). Do not write "(Invited)" in the title. Full names of authors are preferred in the author field, but are not

  19. Nonequilibrium superconducting detectors

    Science.gov (United States)

    Cristiano, R.; Ejrnaes, M.; Esposito, E.; Lisitskyi, M. P.; Nappi, C.; Pagano, S.; Perez de Lara, D.

    2006-03-01

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  20. Nonequilibrium superconducting detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cristiano, R [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Ejrnaes, M [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); INFN Sezione di Napoli, 80126 Naples (Italy); Esposito, E [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Lisitskyi, M P [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Nappi, C [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Pagano, S [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Dipartimento di Fisica, Universita di Salerno, 84081 Baronissi (Saudi Arabia) (Italy); Perez de Lara, D [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy)

    2006-03-15

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.