Wide field of view common-path lateral-shearing digital holographic interference microscope.

Science.gov (United States)

Vora, Priyanka; Trivedi, Vismay; Mahajan, Swapnil; Patel, Nimit; Joglekar, Mugdha; Chhaniwal, Vani; Moradi, Ali-Reza; Javidi, Bahram; Anand, Arun

2017-12-01

Quantitative three-dimensional (3-D) imaging of living cells provides important information about the cell morphology and its time variation. Off-axis, digital holographic interference microscopy is an ideal tool for 3-D imaging, parameter extraction, and classification of living cells. Two-beam digital holographic microscopes, which are usually employed, provide high-quality 3-D images of micro-objects, albeit with lower temporal stability. Common-path digital holographic geometries, in which the reference beam is derived from the object beam, provide higher temporal stability along with high-quality 3-D images. Self-referencing geometry is the simplest of the common-path techniques, in which a portion of the object beam itself acts as the reference, leading to compact setups using fewer optical elements. However, it has reduced field of view, and the reference may contain object information. Here, we describe the development of a common-path digital holographic microscope, employing a shearing plate and converting one of the beams into a separate reference by employing a pin-hole. The setup is as compact as self-referencing geometry, while providing field of view as wide as that of a two-beam microscope. The microscope is tested by imaging and quantifying the morphology and dynamics of human erythrocytes. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Volume Holographic Storage of Digital Data Implemented in Photorefractive Media

Science.gov (United States)

Heanue, John Frederick

A holographic data storage system is fundamentally different from conventional storage devices. Information is recorded in a volume, rather than on a two-dimensional surface. Data is transferred in parallel, on a page-by -page basis, rather than serially. These properties, combined with a limited need for mechanical motion, lead to the potential for a storage system with high capacity, fast transfer rate, and short access time. The majority of previous volume holographic storage experiments have involved direct storage and retrieval of pictorial information. Success in the development of a practical holographic storage device requires an understanding of the performance capabilities of a digital system. This thesis presents a number of contributions toward this goal. A description of light diffraction from volume gratings is given. The results are used as the basis for a theoretical and numerical analysis of interpage crosstalk in both angular and wavelength multiplexed holographic storage. An analysis of photorefractive grating formation in photovoltaic media such as lithium niobate is presented along with steady-state expressions for the space-charge field in thermal fixing. Thermal fixing by room temperature recording followed by ion compensation at elevated temperatures is compared to simultaneous recording and compensation at high temperature. In particular, the tradeoff between diffraction efficiency and incomplete Bragg matching is evaluated. An experimental investigation of orthogonal phase code multiplexing is described. Two unique capabilities, the ability to perform arithmetic operations on stored data pages optically, rather than electronically, and encrypted data storage, are demonstrated. A comparison of digital signal representations, or channel codes, is carried out. The codes are compared in terms of bit-error rate performance at constant capacity. A well-known one-dimensional digital detection technique, maximum likelihood sequence estimation, is

A direct-view customer-oriented digital holographic camera

Science.gov (United States)

Besaga, Vira R.; Gerhardt, Nils C.; Maksimyak, Peter P.; Hofmann, Martin R.

2018-01-01

In this paper, we propose a direct-view digital holographic camera system consisting mostly of customer-oriented components. The camera system is based on standard photographic units such as camera sensor and objective and is adapted to operate under off-axis external white-light illumination. The common-path geometry of the holographic module of the system ensures direct-view operation. The system can operate in both self-reference and self-interference modes. As a proof of system operability, we present reconstructed amplitude and phase information of a test sample.

Multilevel recording of complex amplitude data pages in a holographic data storage system using digital holography.

Science.gov (United States)

Nobukawa, Teruyoshi; Nomura, Takanori

2016-09-05

A holographic data storage system using digital holography is proposed to record and retrieve multilevel complex amplitude data pages. Digital holographic techniques are capable of modulating and detecting complex amplitude distribution using current electronic devices. These techniques allow the development of a simple, compact, and stable holographic storage system that mainly consists of a single phase-only spatial light modulator and an image sensor. As a proof-of-principle experiment, complex amplitude data pages with binary amplitude and four-level phase are recorded and retrieved. Experimental results show the feasibility of the proposed holographic data storage system.

Fine Metal Mask 3-Dimensional Measurement by using Scanning Digital Holographic Microscope

Science.gov (United States)

Shin, Sanghoon; Yu, Younghun

2018-04-01

For three-dimensional microscopy, fast and high axial resolution are very important. Extending the depth of field for digital holographic is necessary for three-dimensional measurements of thick samples. We propose an optical sectioning method for optical scanning digital holography that is performed in the frequency domain by spatial filtering of a reconstructed amplitude image. We established a scanning dual-wavelength off-axis digital holographic microscope to measure samples that exhibit a large amount of coherent noise and a thickness larger than the depth of focus of the objective lens. As a demonstration, we performed a three-dimensional measurement of a fine metal mask with a reconstructed sectional phase image and filtering with a reconstructed amplitude image.

Experimental research of digital holographic microscopic measuring

Science.gov (United States)

Zhu, Xueliang; Chen, Feifei; Li, Jicheng

2013-06-01

Digital holography is a new imaging technique, which is developed on the base of optical holography, Digital processing, and Computer techniques. It is using CCD instead of the conventional silver to record hologram, and then reproducing the 3D contour of the object by the way of computer simulation. Compared with the traditional optical holographic, the whole process is of simple measuring, lower production cost, faster the imaging speed, and with the advantages of non-contact real-time measurement. At present, it can be used in the fields of the morphology detection of tiny objects, micro deformation analysis, and biological cells shape measurement. It is one of the research hot spot at home and abroad. This paper introduced the basic principles and relevant theories about the optical holography and Digital holography, and researched the basic questions which influence the reproduce images in the process of recording and reconstructing of the digital holographic microcopy. In order to get a clear digital hologram, by analyzing the optical system structure, we discussed the recording distance and of the hologram. On the base of the theoretical studies, we established a measurement and analyzed the experimental conditions, then adjusted them to the system. To achieve a precise measurement of tiny object in three-dimension, we measured MEMS micro device for example, and obtained the reproduction three-dimensional contour, realized the three dimensional profile measurement of tiny object. According to the experiment results consider: analysis the reference factors between the zero-order term and a pair of twin-images by the choice of the object light and the reference light and the distance of the recording and reconstructing and the characteristics of reconstruction light on the measurement, the measurement errors were analyzed. The research result shows that the device owns certain reliability.

Innovative re-creation of realities in a holographic digital form

Science.gov (United States)

Wang, Shuo; Hebblewhite, Richard; Osanlou, Ardieshir; Excell, Peter; Di Gennaro, Sonia; Shi, Lishen

2014-02-01

Only nature can create, whereas humans can only re-create. This article is an exploration of synergies between art and science in digital holography in relation to art practice and the making of holograms as art works. This is achieved through involvement in the re-creation of a real object (a telescope) as a case study. A digital three-dimensional model suitable for holographic hard copy re-creation is produced. To explore special and immersive environment, real geographical landscape background from Google Earth is added to the model. After a brief introduction to visual art within the context of two and three-dimensional imaging in the form photography and holography, the whole process of producing the three-dimensional model and the environment in which it should be presented, ready for holographic printing is explained.

High speed digital holographic interferometry for hypersonic flow visualization

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Hegde, G. M.; Jagdeesh, G.; Reddy, K. P. J.

2013-06-01

Optical imaging techniques have played a major role in understanding the flow dynamics of varieties of fluid flows, particularly in the study of hypersonic flows. Schlieren and shadowgraph techniques have been the flow diagnostic tools for the investigation of compressible flows since more than a century. However these techniques provide only the qualitative information about the flow field. Other optical techniques such as holographic interferometry and laser induced fluorescence (LIF) have been used extensively for extracting quantitative information about the high speed flows. In this paper we present the application of digital holographic interferometry (DHI) technique integrated with short duration hypersonic shock tunnel facility having 1 ms test time, for quantitative flow visualization. Dynamics of the flow fields in hypersonic/supersonic speeds around different test models is visualized with DHI using a high-speed digital camera (0.2 million fps). These visualization results are compared with schlieren visualization and CFD simulation results. Fringe analysis is carried out to estimate the density of the flow field.

Digital Holographic Microscopy: Quantitative Phase Imaging and Applications in Live Cell Analysis

Science.gov (United States)

Kemper, Björn; Langehanenberg, Patrik; Kosmeier, Sebastian; Schlichthaber, Frank; Remmersmann, Christian; von Bally, Gert; Rommel, Christina; Dierker, Christian; Schnekenburger, Jürgen

The analysis of complex processes in living cells creates a high demand for fast and label-free methods for online monitoring. Widely used fluorescence methods require specific labeling and are often restricted to chemically fixated samples. Thus, methods that offer label-free and minimally invasive detection of live cell processes and cell state alterations are of particular interest. In combination with light microscopy, digital holography provides label-free, multi-focus quantitative phase imaging of living cells. In overview, several methods for digital holographic microscopy (DHM) are presented. First, different experimental setups for the recording of digital holograms and the modular integration of DHM into common microscopes are described. Then the numerical processing of digitally captured holograms is explained. This includes the description of spatial and temporal phase shifting techniques, spatial filtering based reconstruction, holographic autofocusing, and the evaluation of self-interference holograms. Furthermore, the usage of partial coherent light and multi-wavelength approaches is discussed. Finally, potentials of digital holographic microscopy for quantitative cell imaging are illustrated by results from selected applications. It is shown that DHM can be used for automated tracking of migrating cells and cell thickness monitoring as well as for refractive index determination of cells and particles. Moreover, the use of DHM for label-free analysis in fluidics and micro-injection monitoring is demonstrated. The results show that DHM is a highly relevant method that allows novel insights in dynamic cell biology, with applications in cancer research and for drugs and toxicity testing.

Digital Holographic Microscopy Principles, Techniques, and Applications

CERN Document Server

Kim, Myung K

2011-01-01

Digital holography is an emerging field of new paradigm in general imaging applications. By replacing the photochemical procedures with electronic imaging and having a direct numerical access to the complex optical field, a wide range of new imaging capabilities become available, many of them difficult or infeasible in conventional holography. An increasing number of researchers—not only in optical physics and optical engineering, but also in diverse applications areas such as microbiology, medicine, marine science, particle analysis, microelectromechanics, and metrology—are realizing and exploiting the new capabilities of digital holography. Digital Holographic Microscopy: Principles, Techniques, and Applications, by Dr. Myung K. Kim, is intended to provide a brief but consistent introduction to the principles of digital holography as well as to give an organized overview of the large number of techniques and applications being developed. This will also shed some light on the range of possibilities for f...

Analysis of reconstructed interference fields in digital holographic interferometry using the polynomial phase transform

International Nuclear Information System (INIS)

Gorthi, Sai Siva; Rastogi, Pramod

2009-01-01

A noisy wrapped phase map is the end-output of commonly employed phase estimation methods in digital holographic interferometry. Hence filtering and unwrapping are necessary to obtain continuous phase distributions. This paper introduces a new approach for phase estimation in digital holographic interferometry using the polynomial phase transform. The proposed approach directly provides an accurate estimation of the unwrapped phase distribution from a noisy reconstructed interference field, thereby bypassing cumbersome and error-prone filtering and 2D phase unwrapping procedures

Holographic fluorescence microscopy with incoherent digital holographic adaptive optics.

Science.gov (United States)

Jang, Changwon; Kim, Jonghyun; Clark, David C; Lee, Seungjae; Lee, Byoungho; Kim, Myung K

2015-01-01

Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: a wavefront sensor, wavefront corrector, and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, for example, lenslet arrays for sensing or multiactuator deformable mirrors for correcting. We have previously introduced an alternate approach based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile are possible not only with conventional coherent digital holography, but also with a new type of digital holography using incoherent light: selfinterference incoherent digital holography (SIDH). The SIDH generates a complex—i.e., amplitude plus phase—hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. Adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media.

Examining live cell cultures during apoptosis by digital holographic phase imaging and Raman spectroscopy

Science.gov (United States)

Khmaladze, Alexander

2017-11-01

Cellular apoptosis is a unique, organized series of events, leading to programmed cell death. In this work, we present a combined digital holography/Raman spectroscopy technique to study live cell cultures during apoptosis. Digital holographic microscopy measurements of live cell cultures yield information about cell shape and volume, changes to which are indicative of alterations in cell cycle and initiation of cell death mechanisms. Raman spectroscopic measurements provide complementary information about cells, such as protein, lipid and nucleic acid content, and the spectral signatures associated with structural changes in molecules. Our work indicates that the chemical changes in proteins, which were detected by Raman measurements, preceded morphological changes, which were seen with digital holographic microscopy.

Moving picture recording and observation of femtosecond light pulse propagation using a rewritable holographic material

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Seiji; Takimoto, Tetsuya; Tosa, Kazuya; Kakue, Takashi [Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo, Kyoto 606-8585 (Japan); Awatsuji, Yasuhiro, E-mail: awatsuji@kit.ac.jp [Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo, Kyoto 606-8585 (Japan); Nishio, Kenzo [Advanced Technology Center, Kyoto Institute of Technology, Matsugasaki, Sakyo, Kyoto 606-8585 (Japan); Ura, Shogo [Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo, Kyoto 606-8585 (Japan); Kubota, Toshihiro [Kubota Holography Laboratory, Corporation, Nishihata 34-1-609, Ogura, Uji 611-0042 (Japan)

2011-08-01

We succeeded in recording and observing femtosecond light pulse propagation as a form of moving picture by means of light-in-flight recording by holography using a rewritable holographic material, for the first time. We used a femtosecond pulsed laser whose center wavelength and duration were 800 nm and {approx}120 fs, respectively. A photo-conductor plastic hologram was used as a rewritable holographic material. The femtosecond light pulse was collimated and obliquely incident to the diffuser plate. The behavior of the cross-section between the collimated femtosecond light pulse and the diffuser plate was recorded on the photo-conductor plastic hologram. We experimentally obtained a spatially and temporally continuous moving picture of the femtosecond light pulse propagation for 58.3 ps. Meanwhile, we also investigated the rewritable performance of the photo-conductor plastic hologram. As a result, we confirmed that ten-time rewriting was possible for a photo-conductor plastic hologram.

Digital stereo-holographic microscopy for studying three-dimensional particle dynamics

Science.gov (United States)

Byeon, Hyeokjun; Go, Taesik; Lee, Sang Joon

2018-06-01

A digital stereo-holographic microscopy (DsHM) with two viewing angles is proposed to measure 3D information of microscale particles. This approach includes two volumetric recordings and numerical reconstruction, and it involves the combination of separately reconstructed holograms. The 3D positional information of a particle was determined by searching the center of the overlapped reconstructed volume. After confirming the proposed technique using static spherical particles, the 3D information of moving particles suspended in a Hagen-Poiseiulle flow was successfully obtained. Moreover, the 3D information of nonspherical particles, including ellipsoidal particles and red blood cells, were measured using the proposed technique. In addition to 3D positional information, the orientation and shape of the test samples were obtained from the plane images by slicing the overlapped volume perpendicular to the directions of the image recordings. This DsHM technique will be useful in analyzing the 3D dynamic behavior of various nonspherical particles, which cannot be measured by conventional digital holographic microscopy.

Dynamics and morphometric characterization of hippocampus neurons using digital holographic microscopy

Science.gov (United States)

Elkatlawy, Saeid; Gomariz, María.; Soto-Sánchez, Cristina; Martínez Navarrete, Gema; Fernández, Eduardo; Fimia, Antonio

2014-05-01

In this paper we report on the use of digital holographic microscopy for 3D real time imaging of cultured neurons and neural networks, in vitro. Digital holographic microscopy is employed as an assessment tool to study the biophysical origin of neurodegenerative diseases. Our study consists in the morphological characterization of the axon, dendrites and cell bodies. The average size and thickness of the soma were 21 and 13 μm, respectively. Furthermore, the average size and diameter of some randomly selected neurites were 4.8 and 0.89 μm, respectively. In addition, the spatiotemporal growth process of cellular bodies and extensions was fitted to by a non-linear behavior of the nerve system. Remarkably, this non-linear process represents the relationship between the growth process of cellular body with respect to the axon and dendrites of the neurons.

Adaptive nonseparable vector lifting scheme for digital holographic data compression.

Science.gov (United States)

Xing, Yafei; Kaaniche, Mounir; Pesquet-Popescu, Béatrice; Dufaux, Frédéric

2015-01-01

Holographic data play a crucial role in recent three-dimensional imaging as well as microscopic applications. As a result, huge amounts of storage capacity will be involved for this kind of data. Therefore, it becomes necessary to develop efficient hologram compression schemes for storage and transmission purposes. In this paper, we focus on the shifted distance information, obtained by the phase-shifting algorithm, where two sets of difference data need to be encoded. More precisely, a nonseparable vector lifting scheme is investigated in order to exploit the two-dimensional characteristics of the holographic contents. Simulations performed on different digital holograms have shown the effectiveness of the proposed method in terms of bitrate saving and quality of object reconstruction.

Single-shot full resolution region-of-interest (ROI) reconstruction in image plane digital holographic microscopy

Science.gov (United States)

Singh, Mandeep; Khare, Kedar

2018-05-01

We describe a numerical processing technique that allows single-shot region-of-interest (ROI) reconstruction in image plane digital holographic microscopy with full pixel resolution. The ROI reconstruction is modelled as an optimization problem where the cost function to be minimized consists of an L2-norm squared data fitting term and a modified Huber penalty term that are minimized alternately in an adaptive fashion. The technique can provide full pixel resolution complex-valued images of the selected ROI which is not possible to achieve with the commonly used Fourier transform method. The technique can facilitate holographic reconstruction of individual cells of interest from a large field-of-view digital holographic microscopy data. The complementary phase information in addition to the usual absorption information already available in the form of bright field microscopy can make the methodology attractive to the biomedical user community.

Multispectral digital lensless holographic microscopy: from femtosecond laser to white light LED

International Nuclear Information System (INIS)

Garcia-Sucerquia, J

2015-01-01

The use of femtosecond laser radiation and super bright white LED in digital lensless holographic microscopy is presented. For the ultrafast laser radiation two different configurations of operation of the microscope are presented and the dissimilar performance of each one analyzed. The microscope operating with a super bright white light LED in combination with optical filters shows very competitive performance as it is compared with more expensive optical sources. The broadband emission of both radiation sources allows the multispectral imaging of biological samples to obtain spectral responses and/or full color images of the microscopic specimens; sections of the head of a Drosophila melanogaster fly are imaged in this contribution. The simple, solid, compact, lightweight, and reliable architecture of digital lensless holographic microscopy operating with broadband light sources to image biological specimens exhibiting micrometer-sized details is evaluated in the present contribution. (paper)

Accurate reconstruction in digital holographic microscopy using antialiasing shift-invariant contourlet transform

Science.gov (United States)

Zhang, Xiaolei; Zhang, Xiangchao; Xu, Min; Zhang, Hao; Jiang, Xiangqian

2018-03-01

The measurement of microstructured components is a challenging task in optical engineering. Digital holographic microscopy has attracted intensive attention due to its remarkable capability of measuring complex surfaces. However, speckles arise in the recorded interferometric holograms, and they will degrade the reconstructed wavefronts. Existing speckle removal methods suffer from the problems of frequency aliasing and phase distortions. A reconstruction method based on the antialiasing shift-invariant contourlet transform (ASCT) is developed. Salient edges and corners have sparse representations in the transform domain of ASCT, and speckles can be recognized and removed effectively. As subsampling in the scale and directional filtering schemes is avoided, the problems of frequency aliasing and phase distortions occurring in the conventional multiscale transforms can be effectively overcome, thereby improving the accuracy of wavefront reconstruction. As a result, the proposed method is promising for the digital holographic measurement of complex structures.

Three-dimensional motion measurements of free-swimming microorganisms using digital holographic microscopy

International Nuclear Information System (INIS)

Lee, Sang Joon; Seo, Kyung Won; Choi, Yong Seok; Sohn, Myong Hwan

2011-01-01

A digital holographic microscope is employed to measure the 3D motion of free-swimming microorganisms. The focus function used to quantify image sharpness provides a better depth-directional accuracy with a smaller depth-of-focus compared with the intensity method in determining the depth-directional position of spherical particles of various diameters. The focus function is then applied to measure the 3D positions of free-swimming microorganisms, namely dinoflagellates C. polykrikoides and P. minimum. Both automatic segmentation and proper selection of a focus function for a selected segment are important processes in measuring the positional information of two free-swimming microorganisms of different shapes with various width-to-length ratios. The digital holographic microscopy technique improved in this work is useful for measuring 3D swimming trajectories, velocities and attitudes of hundreds of microorganisms simultaneously. It also exhibits exceptional depth-directional accuracy

Accuracy concerns in digital speckle photography combined with Fresnel digital holographic interferometry

Science.gov (United States)

Zhao, Yuchen; Zemmamouche, Redouane; Vandenrijt, Jean-François; Georges, Marc P.

2018-05-01

A combination of digital holographic interferometry (DHI) and digital speckle photography (DSP) allows in-plane and out-of-plane displacement measurement between two states of an object. The former can be determined by correlating the two speckle patterns whereas the latter is given by the phase difference obtained from DHI. We show that the amplitude of numerically reconstructed object wavefront obtained from Fresnel in-line digital holography (DH), in combination with phase shifting techniques, can be used as speckle patterns in DSP. The accuracy of in-plane measurement is improved after correcting the phase errors induced by reference wave during reconstruction process. Furthermore, unlike conventional imaging system, Fresnel DH offers the possibility to resize the pixel size of speckle patterns situated on the reconstruction plane under the same optical configuration simply by zero-padding the hologram. The flexibility of speckle size adjustment in Fresnel DH ensures the accuracy of estimation result using DSP.

Digital holographic-based cancellable biometric for personal authentication

International Nuclear Information System (INIS)

Verma, Gaurav; Sinha, Aloka

2016-01-01

In this paper, we propose a new digital holographic-based cancellable biometric scheme for personal authentication and verification. The realization of cancellable biometric is presented by using an optoelectronic experimental approach, in which an optically recorded hologram of the fingerprint of a person is numerically reconstructed. Each reconstructed feature has its own perspective, which is utilized to generate user-specific fingerprint features by using a feature-extraction process. New representations of the user-specific fingerprint features can be obtained from the same hologram, by changing the reconstruction distance (d) by an amount Δd between the recording plane and the reconstruction plane. This parameter is the key to make the cancellable user-specific fingerprint features using a digital holographic technique, which allows us to choose different reconstruction distances when reissuing the user-specific fingerprint features in the event of compromise. We have shown theoretically that each user-specific fingerprint feature has a unique identity with a high discrimination ability, and the chances of a match between them are minimal. In this aspect, a recognition system has also been demonstrated using the fingerprint biometric of the enrolled person at a particular reconstruction distance. For the performance evaluation of a fingerprint recognition system—the false acceptance ratio, the false rejection ratio and the equal error rate are calculated using correlation. The obtained results show good discrimination ability between the genuine and the impostor populations with the highest recognition rate of 98.23%. (paper)

Three-Dimensional Identification of Microorganisms Using a Digital Holographic Microscope

Directory of Open Access Journals (Sweden)

Ning Wu

2013-01-01

Full Text Available This paper reports a method for three-dimensional (3D analysis of shift-invariant pattern recognition and applies to holographic images digitally reconstructed from holographic microscopes. It is shown that the sequential application of a 2D filter to the plane-by-plane reconstruction of an optical field is exactly equivalent to the application of a more general filter with a 3D impulse response. We show that any 3D filters with arbitrary impulse response can be implemented in this way. This type of processing is applied to the two-class problem of distinguishing different types of bacteria. It is shown that the proposed technique can be easily implemented using a modified microscope to develop a powerful and cost-effective system with great potential for biological screening.

High-speed digital holographic interferometry for vibration measurement

International Nuclear Information System (INIS)

Pedrini, Giancarlo; Osten, Wolfgang; Gusev, Mikhail E.

2006-01-01

A system based on digital holographic interferometry for the measurement of vibrations is presented. A high-power continuous laser(10 W) and a high-speed CCD camera are used. Hundreds of holograms of an object that has been subjected to dynamic deformation are recorded. The acquisition speed and the time of exposure of the detector are determined by the vibration frequency. Two methods are presented for triggering the camera in order to acquire at a given phase of the vibration. The phase of the wavefront is calculated from the recorded holograms by use of a two-dimensional digital Fourier-transform method. The deformation of the object is obtained from the phase. By combination of the deformations recorded at different times it is possible to reconstruct the vibration of the object

Color correction for chromatic distortion in a multi-wavelength digital holographic system

International Nuclear Information System (INIS)

Lin, Li-Chien; Huang, Yi-Lun; Tu, Han-Yen; Lai, Xin-Ji; Cheng, Chau-Jern

2011-01-01

A multi-wavelength digital holographic (MWDH) system has been developed to record and reconstruct color images. In comparison to working with digital cameras, however, high-quality color reproduction is difficult to achieve, because of the imperfections from the light sources, optical components, optical recording devices and recording processes. Thus, we face the problem of correcting the colors altered during the digital holographic process. We therefore propose a color correction scheme to correct the chromatic distortion caused by the MWDH system. The scheme consists of two steps: (1) creating a color correction profile and (2) applying it to the correction of the distorted colors. To create the color correction profile, we generate two algorithms: the sequential algorithm and the integrated algorithm. The ColorChecker is used to generate the distorted colors and their desired corrected colors. The relationship between these two color patches is fixed into a specific mathematical model, the parameters of which are estimated, creating the profile. Next, the profile is used to correct the color distortion of images, capturing and preserving the original vibrancy of the reproduced colors for different reconstructed images

Movies of cellular and sub-cellular motion by digital holographic microscopy

Directory of Open Access Journals (Sweden)

Yu Lingfeng

2006-03-01

Full Text Available Abstract Background Many biological specimens, such as living cells and their intracellular components, often exhibit very little amplitude contrast, making it difficult for conventional bright field microscopes to distinguish them from their surroundings. To overcome this problem phase contrast techniques such as Zernike, Normarsky and dark-field microscopies have been developed to improve specimen visibility without chemically or physically altering them by the process of staining. These techniques have proven to be invaluable tools for studying living cells and furthering scientific understanding of fundamental cellular processes such as mitosis. However a drawback of these techniques is that direct quantitative phase imaging is not possible. Quantitative phase imaging is important because it enables determination of either the refractive index or optical thickness variations from the measured optical path length with sub-wavelength accuracy. Digital holography is an emergent phase contrast technique that offers an excellent approach in obtaining both qualitative and quantitative phase information from the hologram. A CCD camera is used to record a hologram onto a computer and numerical methods are subsequently applied to reconstruct the hologram to enable direct access to both phase and amplitude information. Another attractive feature of digital holography is the ability to focus on multiple focal planes from a single hologram, emulating the focusing control of a conventional microscope. Methods A modified Mach-Zender off-axis setup in transmission is used to record and reconstruct a number of holographic amplitude and phase images of cellular and sub-cellular features. Results Both cellular and sub-cellular features are imaged with sub-micron, diffraction-limited resolution. Movies of holographic amplitude and phase images of living microbes and cells are created from a series of holograms and reconstructed with numerically adjustable

Pulsed recording of anisotropy and holographic polarization gratings in azo-polymethacrylates with different molecular architectures

DEFF Research Database (Denmark)

Forcén, Patricia; Oriol, Luis; Alcala, Rafael

2008-01-01

Recording of anisotropy and holographic polarization gratings using 532 nm, 4 ns light pulses has been carried out in thin films of polymers with the same azobenzene content (20 wt %) and different molecular architectures. Random and block copolymers comprising azobenzene and methylmethacrylate (...

Measurement of a 3D Ultrasonic Wavefield Using Pulsed Laser Holographic Microscopy for Ultrasonic Nondestructive Evaluation

Directory of Open Access Journals (Sweden)

Xing Wang

2018-02-01

Full Text Available In ultrasonic array imaging, 3D ultrasonic wavefields are normally recorded by an ultrasonic piezo array transducer. Its performance is limited by the configuration and size of the array transducer. In this paper, a method based on digital holographic interferometry is proposed to record the 3D ultrasonic wavefields instead of the array transducer, and the measurement system consisting of a pulsed laser, ultrasonic excitation, and synchronization and control circuit is designed. A consecutive sequence of holograms of ultrasonic wavefields are recorded by the system. The interferograms are calculated from the recorded holograms at different time sequence. The amplitudes and phases of the transient ultrasonic wavefields are recovered from the interferograms by phase unwrapping. The consecutive sequence of transient ultrasonic wavefields are stacked together to generate 3D ultrasonic wavefields. Simulation and experiments are carried out to verify the proposed technique, and preliminary results are presented.

Measurement of Three-Dimensional Deformations by Phase-Shifting Digital Holographic Interferometry

Directory of Open Access Journals (Sweden)

Percival Almoro

2003-06-01

Full Text Available Out-of-plane deformations of a cantilever were measured using phase-shifting digital holographicinterferometry (PSDHI and the Fourier transform method (FTM. The cantilever was recorded in twodifferent states, and holograms were stored electronically with a charge-coupled device (CCD camera.When the holograms are superimposed and reconstructed jointly, a holographic interferogram results.The three-dimensional (3D surface deformations were successfully visualized by applying FTM toholographic interferogram analysis. The minimum surface displacement measured was 0.317 µm. Theprocessing time for the digital reconstruction and visualization of 3D deformation took about 1 minute.The technique was calibrated using Michelson interferometry setup.

In-line digital holographic sensor for monitoring and characterizing marine particulates

International Nuclear Information System (INIS)

Owen, Robert B.; Zozulya, Alex A.

2000-01-01

We report an in-line digital holographic sensor (DHS) for monitoring and characterizing marine particulates. This system images individual particles over a deep depth of field (>25 cm) with a resolution of 5 μm. The DHS projects a collimated beam through the water column and onto a lensless CCD array. Some light is diffracted by particulates and forms an object beam; the undeflected remainder constitutes the reference beam. The two beams combine at the CCD array and create an in-line hologram, which is then numerically reconstructed. The DHS eliminates many problems traditionally associated with holography. The CCD recording material considerably lowers the exposure time and eliminates most vibration problems. The laser power needs are low; the DHS uses a small 10-mW diode laser. Rapid numerical reconstruction eliminates photographic processing and optical reconstruction. We successfully operated the DHS underwater on a remotely operated vehicle; our test results include tracing a single particle from one hologram to the next, thus deriving a velocity vector for marine mass transport. We outline our digital holographic reconstruction procedure, and present our graphical user interface and user software tools. The DHS is particularly useful for providing in situ ground-truth measurements for environmental remote sensing. (c) 2000 Society of Photo-Optical Instrumentation Engineers

Real-time holographic endoscopy

Science.gov (United States)

Smigielski, Paul; Albe, Felix; Dischli, Bernard

1992-08-01

Some new experiments concerning holographic endoscopy are presented. The quantitative measurements of deformations of objects are obtained by the double-exposure and double- reference beam method, using either a cw-laser or a pulsed laser. Qualitative experiments using an argon laser with time-average holographic endoscopy are also presented. A video film on real-time endoscopic holographic interferometry was recorded with the help of a frequency-doubled YAG-laser working at 25 Hz for the first time.

Image plane digital holographic microscope for the inspection of ferroelectric single crystals.

Czech Academy of Sciences Publication Activity Database

Psota, Pavel; Mokrý, Pavel; Lédl, Vít; Vojtíšek, Petr

2016-01-01

Roč. 55, č. 12 (2016), č. článku 121731. ISSN 0091-3286 R&D Projects: GA ČR(CZ) GA14-32228S Institutional support: RVO:61389021 Keywords : Digital holography * barium titanate * domain pattern * ferroelectric crystals * holographic microscopy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.082, year: 2016 http://dx.doi.org/10.1117/1.OE.55.12.121731

Label-free quantitative cell division monitoring of endothelial cells by digital holographic microscopy

Science.gov (United States)

Kemper, Björn; Bauwens, Andreas; Vollmer, Angelika; Ketelhut, Steffi; Langehanenberg, Patrik; Müthing, Johannes; Karch, Helge; von Bally, Gert

2010-05-01

Digital holographic microscopy (DHM) enables quantitative multifocus phase contrast imaging for nondestructive technical inspection and live cell analysis. Time-lapse investigations on human brain microvascular endothelial cells demonstrate the use of DHM for label-free dynamic quantitative monitoring of cell division of mother cells into daughter cells. Cytokinetic DHM analysis provides future applications in toxicology and cancer research.

Digital holographic reconstruction detection of localized corrosion arising from scratches

Directory of Open Access Journals (Sweden)

LIANG WANG

2010-04-01

Full Text Available In this study, electrochemical methods and the digital holographic reconstruction technique were combined to detect the localized scratch-induced corrosion process of Alloy 690 in 0.50 mol dm-3 H2SO4 containing 0.10 mol dm-3 NaCl. The numerical reconstruction method has been proved to be an effective technique to detect changes of solution concentration. One can obtain direct information from the reconstructed images and capture subtle more revealing changes. It provides a method to detect localized corrosion arising from scratches.

Digital holographic microscopy: a novel tool to study the morphology, physiology and ecology of diatoms

NARCIS (Netherlands)

Zetsche, E.-M.; El Mallahi, A.; Meysman, F.J.R.

2016-01-01

Recent advances in optical components, computational hardware and image analysis algorithms have led to the development of a powerful new imaging tool, digital holographic microscopy (DHM). So far, DHM has been predominantly applied in the life sciences and medical research, and here, we evaluate

Early cell death detection with digital holographic microscopy.

Directory of Open Access Journals (Sweden)

Nicolas Pavillon

Full Text Available BACKGROUND: Digital holography provides a non-invasive measurement of the quantitative phase shifts induced by cells in culture, which can be related to cell volume changes. It has been shown previously that regulation of cell volume, in particular as it relates to ionic homeostasis, is crucially involved in the activation/inactivation of the cell death processes. We thus present here an application of digital holographic microscopy (DHM dedicated to early and label-free detection of cell death. METHODS AND FINDINGS: We provide quantitative measurements of phase signal obtained on mouse cortical neurons, and caused by early neuronal cell volume regulation triggered by excitotoxic concentrations of L-glutamate. We show that the efficiency of this early regulation of cell volume detected by DHM, is correlated with the occurrence of subsequent neuronal death assessed with the widely accepted trypan blue method for detection of cell viability. CONCLUSIONS: The determination of the phase signal by DHM provides a simple and rapid optical method for the early detection of cell death.

3D measurements of live cells via digital holographic microscopy and terahertz spectroscopy

Science.gov (United States)

Park, Jun Yong; Oser, Dorian; Iapozzuto, Peter; Norbury, Sean; Mahajan, Supriya; Khmaladze, Alexander; Sharikova, Anna

2016-03-01

This is a study of the central nervous system (CNS) cells, including brain micro vascular endothelial cells (BMV) that constitute the blood brain barrier, and C6 glial cells that are the predominant cell in the brain. The cells are exposed to various chemicals by non-invasive, label-free methods. Digital holographic microscopy (DHM) is a technique that records an interference pattern between an object and reference waves, so that the computationally reconstructed holographic image contains both amplitude and phase information, and 3D images are obtained. The measurement of cell cultures by digital holographic microscopy yields information about cell death mechanisms, since these processes are correlated with individual cell volume. Our in-house DHM combines a visible (red) laser source with a conventional microscope base, and LabVIEW-run data processing. Terahertz spectral signatures are associated with structural changes in molecules and provide complementary information about cells. Both CNS cells BMV and C6 cells are treated with the drug "Methamphetamine" (METH), which induces apoptosis in neuronal cells and exhibits decrease in cell volume, a characteristic of cells undergoing apoptosis (induced cell death). METH can cause CNS cell death by cross-talk between mitochondria-, endoplasmic reticulum-, and receptor-mediated apoptotic events, all of which results in drug induced changes in neuroplasticity and significant neuropathology. Doxorubicin (DOX), a popular anticancer drug, is used as a control. We observe that METH treatment resulted in more pronounced cell volume shrinkage in both the BMV and C6 cells, as compared to DOX-induced cell apoptosis.

Digital holographic microscopy for toxicity testing and cell culture quality control

Science.gov (United States)

Kemper, Björn

2018-02-01

For the example of digital holographic microscopy (DHM), it is illustrated how label-free biophysical parameter sets can be extracted from quantitative phase images of adherent and suspended cells, and how the retrieved data can be applied for in-vitro toxicity testing and cell culture quality assessment. This includes results from the quantification of the reactions of cells to toxic substances as well as data from sophisticated monitoring of cell alterations that are related to changes of cell culture conditions.

Simple concept for a wide-field lensless digital holographic microscope using a laser diode

Directory of Open Access Journals (Sweden)

Adinda-Ougba A.

2015-09-01

Full Text Available Wide-field, lensless digital holographic microscopy is a new microscopic imaging technique for telemedicine and for resource limited setting [1]. In this contribution we propose a very simple wide-field lensless digital holographic microscope using a laser diode. It is based on in-line digital holography which is capable to provide amplitude and phase images of a sample resulting from numerical reconstruction. The numerical reconstruction consists of the angular spectrum propagation method together with a phase retrieval algorithm. Amplitude and phase images of the sample with a resolution of ∽2 µm and with ∽24 mm2 field of view are obtained. We evaluate our setup by imaging first the 1951 USAF resolution test chart to verify the resolution. Second, we record holograms of blood smear and diatoms. The individual specimen can be easily identified after the numerical reconstruction. Our system is a very simple, compact and low-cost possibility of realizing a microscope capable of imaging biological samples. The availability of the phase provide topographic information of the sample extending the application of this system to be not only for biological sample but also for transparent microstructure. It is suitable for fault detection, shape and roughness measurements of these structures.

Efficient Phase Unwrapping Architecture for Digital Holographic Microscopy

Directory of Open Access Journals (Sweden)

Wen-Jyi Hwang

2011-09-01

Full Text Available This paper presents a novel phase unwrapping architecture for accelerating the computational speed of digital holographic microscopy (DHM. A fast Fourier transform (FFT based phase unwrapping algorithm providing a minimum squared error solution is adopted for hardware implementation because of its simplicity and robustness to noise. The proposed architecture is realized in a pipeline fashion to maximize through put of thecomputation. Moreover, the number of hardware multipliers and dividers are minimized to reduce the hardware costs. The proposed architecture is used as a custom user logic in a system on programmable chip (SOPC for physical performance measurement. Experimental results reveal that the proposed architecture is effective for expediting the computational speed while consuming low hardware resources for designing an embedded DHM system.

Determination of the refractive index of dehydrated cells by means of digital holographic microscopy

Science.gov (United States)

Belashov, A. V.; Zhikhoreva, A. A.; Bespalov, V. G.; Vasyutinskii, O. S.; Zhilinskaya, N. T.; Novik, V. I.; Semenova, I. V.

2017-10-01

Spatial distributions of the integral refractive index in dehydrated cells of human oral cavity epithelium are obtained by means of digital holographic microscopy, and mean refractive index of the cells is determined. The statistical analysis of the data obtained is carried out, and absolute errors of the method are estimated for different experimental conditions.

Necrosis and apoptosis pathways of cell death at photodynamic treatment in vitro as revealed by digital holographic microscopy

Science.gov (United States)

Semenova, I. V.; Belashov, A. V.; Belyaeva, T. N.; Kornilova, E. S.; Salova, A. V.; Zhikhoreva, A. A.; Vasyutinskii, O. S.

2018-02-01

Monitoring of variations in morphological characteristics of cultured HeLa cells after photodynamic treatment with Radachlorin photosensitizer is performed by means of digital holographic microscopy. The observed dose-dependent post-treatment variations of phase shift evidence threshold effect of photodynamic treatment and allow for distinguishing between necrotic or apoptotic pathways of cell death. Results obtained by holographic microscopy were confirmed by means of far-field optical microscopy and confocal fluorescence microscopy with commonly used test assays.

Cellular Dynamics Revealed by Digital Holographic Microscopy☆

KAUST Repository

Marquet, P.

2016-11-22

Digital holographic microscopy (DHM) is a new optical method that provides, without the use of any contrast agent, real-time, three-dimensional images of transparent living cells, with an axial sensitivity of a few tens of nanometers. They result from the hologram numerical reconstruction process, which permits a sub wavelength calculation of the phase shift, produced on the transmitted wave front, by the optically probed cells, namely the quantitative phase signal (QPS). Specifically, in addition to measurements of cellular surface morphometry and intracellular refractive index (RI), various biophysical cellular parameters including dry mass, absolute volume, membrane fluctuations at the nanoscale and biomechanical properties, transmembrane water permeability as swell as current, can be derived from the QPS. This article presents how quantitative phase DHM (QP-DHM) can explored cell dynamics at the nanoscale with a special attention to both the study of neuronal dynamics and the optical resolution of local neuronal network.

Cellular Dynamics Revealed by Digital Holographic Microscopy☆

KAUST Repository

Marquet, P.; Depeursinge, Christian; Jourdain, P.

2016-01-01

Digital holographic microscopy (DHM) is a new optical method that provides, without the use of any contrast agent, real-time, three-dimensional images of transparent living cells, with an axial sensitivity of a few tens of nanometers. They result from the hologram numerical reconstruction process, which permits a sub wavelength calculation of the phase shift, produced on the transmitted wave front, by the optically probed cells, namely the quantitative phase signal (QPS). Specifically, in addition to measurements of cellular surface morphometry and intracellular refractive index (RI), various biophysical cellular parameters including dry mass, absolute volume, membrane fluctuations at the nanoscale and biomechanical properties, transmembrane water permeability as swell as current, can be derived from the QPS. This article presents how quantitative phase DHM (QP-DHM) can explored cell dynamics at the nanoscale with a special attention to both the study of neuronal dynamics and the optical resolution of local neuronal network.

Synthesis method from low-coherence digital holograms for improvement of image quality in holographic display.

Science.gov (United States)

Mori, Yutaka; Nomura, Takanori

2013-06-01

In holographic displays, it is undesirable to observe the speckle noises with the reconstructed images. A method for improvement of reconstructed image quality by synthesizing low-coherence digital holograms is proposed. It is possible to obtain speckleless reconstruction of holograms due to low-coherence digital holography. An image sensor records low-coherence digital holograms, and the holograms are synthesized by computational calculation. Two approaches, the threshold-processing and the picking-a-peak methods, are proposed in order to reduce random noise of low-coherence digital holograms. The reconstructed image quality by the proposed methods is compared with the case of high-coherence digital holography. Quantitative evaluation is given to confirm the proposed methods. In addition, the visual evaluation by 15 people is also shown.

Polarization digital holographic microscopy using low-cost liquid crystal polarization rotators

Science.gov (United States)

Dovhaliuk, Rostyslav Yu

2018-02-01

Polarization imaging methods are actively used to study anisotropic objects. A number of methods and systems, such as imaging polarimeters, were proposed to measure the state of polarization of light that passed through the object. Digital holographic and interferometric approaches can be used to quantitatively measure both amplitude and phase of a wavefront. Using polarization modulation optics, the measurement capabilities of such interference-based systems can be extended to measure polarization-dependent parameters, such as phase retardation. Different kinds of polarization rotators can be used to alternate the polarization of a reference beam. Liquid crystals are used in a rapidly increasing number of different optoelectronic devices. Twisted nematic liquid crystals are widely used as amplitude modulators in electronic displays and light valves or shutter glass. Such devices are of particular interest for polarization imaging, as they can be used as polarization rotators, and due to large-scale manufacturing have relatively low cost. A simple Mach-Zehnder polarized holographic setup that uses modified shutter glass as a polarization rotator is demonstrated. The suggested approach is experimentally validated by measuring retardation of quarter-wave film.

Research on digital multi-channel pulse height analysis techniques

International Nuclear Information System (INIS)

Xiao Wuyun; Wei Yixiang; Ai Xianyun; Ao Qi

2005-01-01

Multi-channel pulse height analysis techniques are developing in the direction of digitalization. Based on digital signal processing techniques, digital multi-channel analyzers are characterized by powerful pulse processing ability, high throughput, improved stability and flexibility. This paper analyzes key techniques of digital nuclear pulse processing. With MATLAB software, main algorithms are simulated, such as trapezoidal shaping, digital baseline estimation, digital pole-zero/zero-pole compensation, poles and zeros identification. The preliminary general scheme of digital MCA is discussed, as well as some other important techniques about its engineering design. All these lay the foundation of developing homemade digital nuclear spectrometers. (authors)

Automatic cell identification and visualization using digital holographic microscopy with head mounted augmented reality devices.

Science.gov (United States)

O'Connor, Timothy; Rawat, Siddharth; Markman, Adam; Javidi, Bahram

2018-03-01

We propose a compact imaging system that integrates an augmented reality head mounted device with digital holographic microscopy for automated cell identification and visualization. A shearing interferometer is used to produce holograms of biological cells, which are recorded using customized smart glasses containing an external camera. After image acquisition, segmentation is performed to isolate regions of interest containing biological cells in the field-of-view, followed by digital reconstruction of the cells, which is used to generate a three-dimensional (3D) pseudocolor optical path length profile. Morphological features are extracted from the cell's optical path length map, including mean optical path length, coefficient of variation, optical volume, projected area, projected area to optical volume ratio, cell skewness, and cell kurtosis. Classification is performed using the random forest classifier, support vector machines, and K-nearest neighbor, and the results are compared. Finally, the augmented reality device displays the cell's pseudocolor 3D rendering of its optical path length profile, extracted features, and the identified cell's type or class. The proposed system could allow a healthcare worker to quickly visualize cells using augmented reality smart glasses and extract the relevant information for rapid diagnosis. To the best of our knowledge, this is the first report on the integration of digital holographic microscopy with augmented reality devices for automated cell identification and visualization.

Quantitative stain-free and continuous multimodal monitoring of wound healing in vitro with digital holographic microscopy.

Directory of Open Access Journals (Sweden)

Dominik Bettenworth

Full Text Available Impaired epithelial wound healing has significant pathophysiological implications in several conditions including gastrointestinal ulcers, anastomotic leakage and venous or diabetic skin ulcers. Promising drug candidates for accelerating wound closure are commonly evaluated in in vitro wound assays. However, staining procedures and discontinuous monitoring are major drawbacks hampering accurate assessment of wound assays. We therefore investigated digital holographic microscopy (DHM to appropriately monitor wound healing in vitro and secondly, to provide multimodal quantitative information on morphological and functional cell alterations as well as on motility changes upon cytokine stimulation. Wound closure as reflected by proliferation and migration of Caco-2 cells in wound healing assays was studied and assessed in time-lapse series for 40 h in the presence of stimulating epidermal growth factor (EGF and inhibiting mitomycin c. Therefore, digital holograms were recorded continuously every thirty minutes. Morphological changes including cell thickness, dry mass and tissue density were analyzed by data from quantitative digital holographic phase microscopy. Stimulation of Caco-2 cells with EGF or mitomycin c resulted in significant morphological changes during wound healing compared to control cells. In conclusion, DHM allows accurate, stain-free and continuous multimodal quantitative monitoring of wound healing in vitro and could be a promising new technique for assessment of wound healing.

Coherent imaging with incoherent light in digital holographic microscopy

Science.gov (United States)

Chmelik, Radim

2012-01-01

Digital holographic microscope (DHM) allows for imaging with a quantitative phase contrast. In this way it becomes an important instrument, a completely non-invasive tool for a contrast intravital observation of living cells and a cell drymass density distribution measurement. A serious drawback of current DHMs is highly coherent illumination which makes the lateral resolution worse and impairs the image quality by a coherence noise and a parasitic interference. An uncompromising solution to this problem can be found in the Leith concept of incoherent holography. An off-axis hologram can be formed with arbitrary degree of light coherence in systems equipped with an achromatic interferometer and thus the resolution and the image quality typical for an incoherent-light wide-field microscopy can be achieved. In addition, advanced imaging modes based on limited coherence can be utilized. The typical example is a coherence-gating effect which provides a finite axial resolution and makes DHM image similar to that of a confocal microscope. These possibilities were described theoretically using the formalism of three-dimensional coherent transfer functions and proved experimentally by the coherence-controlled holographic microscope which is DHM based on the Leith achromatic interferometer. Quantitative-phase-contrast imaging is demonstrated with incoherent light by the living cancer cells observation and their motility evaluation. The coherence-gating effect was proved by imaging of model samples through a scattering layer and living cells inside an opalescent medium.

Diffraction properties study of reflection volume holographic grating in dispersive photorefractive material under ultra-short pulse readout

Energy Technology Data Exchange (ETDEWEB)

Yi Yingyan; Liu Deming; Liu Hairong, E-mail: yiyingyan0410@163.com [Wuhan National Laboratory for Optoelectronics, School of Optoelectronic Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074 (China)

2011-02-01

Based on the modified Kogelnik diffraction efficiency equation, we study the diffraction intensity spectrum and the total diffraction efficiency of reflection volume holographic gratings in photorefractive media. Taking photorefractive LiNbO{sub 3} crystal as an example, the effect of the grating parameters and the pulse width on the diffraction properties is presented under the influence of crystal material dispersion. Under the combined effects, the diffraction pulse profiles and the total diffraction efficiency are compared with and without crystal material dispersion. The results show that the dispersion will decrease the diffraction intensity. Moreover, when pulse width is smaller or the grating spacing and the grating thickness are larger, the influence of dispersion on diffraction is large. The results of our paper can be used in pulse shaping applications.

Patterns of digital volume pulse waveform and pulse transit time in ...

African Journals Online (AJOL)

In this study the digital volume pulse wave and the pulse transit time of the thumb and big toe were analyzed in young and older subjects some of whom were hypertensive. We aimed to study the components and patterns of the pulse waveform and the pulse transit time and how they might change. Material and Methods: ...

Studying the dynamics of colloidal particles with digital holographic microscopy and electromagnetic scattering solutions

Directory of Open Access Journals (Sweden)

V. N. Manoharan

2011-09-01

Full Text Available Digital holographic microscopy (DHM can measure the 3D positions as well as the scattering properties of colloidal particles in a single 2D image. We describe DHM and our analysis of recorded holograms with exact scattering solutions, which permit the measurement of 3D particle positions with ∼10 nm precision and millisecond time resolution, and discuss studies of the Brownian dynamics of clusters of spheres with DHM.

Investigation of plume dynamics during picosecond laser ablation of H13 steel using high-speed digital holography

Science.gov (United States)

Pangovski, Krste; Otanocha, Omonigho B.; Zhong, Shan; Sparkes, Martin; Liu, Zhu; O'Neill, William; Li, Lin

2017-02-01

Ablation of H13 tool steel using pulse packets with repetition rates of 400 and 1000 kHz and pulse energies of 75 and 44 μ {J}, respectively, is investigated. A drop in ablation efficiency (defined here as the depth per pulse or μ {m}{/}μ {J}) is shown to occur when using pulse energies of E_{{pulse}} > 44 μ {J}, accompanied by a marked difference in crater morphology. A pulsed digital holographic system is applied to image the resulting plumes, showing a persistent plume in both cases. Holographic data are used to calculate the plume absorption and subsequently the fraction of pulse energy arriving at the surface after traversing the plume for different pulse arrival times. A significant proportion of the pulse energy is shown to be absorbed in the plume for E_{{pulse}} > 44 μ {J} for pulse arrival times corresponding to {>}1 MHz pulse repetition rate, shifting the interaction to a vapour-dominated ablation regime, an energetically costlier ablation mechanism.

Ferroelectric domain pattern in barium titanate single crystals studied by means of digital holographic microscopy

Czech Academy of Sciences Publication Activity Database

Mokrý, Pavel; Psota, Pavel; Steiger, Kateřina; Václavík, Jan; Doleček, Roman; Vápenka, David; Lédl, Vít

2016-01-01

Roč. 49, č. 25 (2016), č. článku 255307. ISSN 0022-3727 R&D Projects: GA ČR(CZ) GA14-32228S Institutional support: RVO:61389021 Keywords : ferroelectric domain patterns * electro-optical materials * digital holographic microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.588, year: 2016 http://iopscience.iop.org/article/10.1088/0022-3727/49/25/255307

Fourier transform digital holographic adaptive optics imaging system

Science.gov (United States)

Liu, Changgeng; Yu, Xiao; Kim, Myung K.

2013-01-01

A Fourier transform digital holographic adaptive optics imaging system and its basic principles are proposed. The CCD is put at the exact Fourier transform plane of the pupil of the eye lens. The spherical curvature introduced by the optics except the eye lens itself is eliminated. The CCD is also at image plane of the target. The point-spread function of the system is directly recorded, making it easier to determine the correct guide-star hologram. Also, the light signal will be stronger at the CCD, especially for phase-aberration sensing. Numerical propagation is avoided. The sensor aperture has nothing to do with the resolution and the possibility of using low coherence or incoherent illumination is opened. The system becomes more efficient and flexible. Although it is intended for ophthalmic use, it also shows potential application in microscopy. The robustness and feasibility of this compact system are demonstrated by simulations and experiments using scattering objects. PMID:23262541

Digital pulse shape discrimination

International Nuclear Information System (INIS)

Miller, L. F.; Preston, J.; Pozzi, S.; Flaska, M.; Neal, J.

2007-01-01

Pulse-shape discrimination (PSD) has been utilised for about 40 years as a method to obtain estimates for dose in mixed neutron and photon fields. Digitizers that operate close to GHz are currently available at a reasonable cost, and they can be used to directly sample signals from photomultiplier tubes. This permits one to perform digital PSD rather than the traditional, and well-established, analogous techniques. One issue that complicates PSD for neutrons in mixed fields is that the light output characteristics of typical scintillators available for PSD, such as BC501A, vary as a function of energy deposited in the detector. This behaviour is more easily accommodated with digital processing of signals than with analogous signal processing. Results illustrate the effectiveness of digital PSD. (authors)

High-speed off-axis holographic cinematography with a copper-vapor-pumped dye laser.

Science.gov (United States)

Lauterborn, W; Judt, A; Schmitz, E

1993-01-01

A series of coherent light pulses is generated by pumping a dye laser with the pulsed output of a copper-vapor laser at rates of as much as 20 kHz. Holograms are recorded at this pulse rate on a rotating holographic plate. This technique of high-speed holographic cinematography is demonstrated by viewing the bubble filaments that appear in water under the action of a sound field of high intensity.

A Curious Conundrum; The State of Holographic Portraiture in the 21st Century

International Nuclear Information System (INIS)

Taylor, R

2013-01-01

The technology of producing (true) hologram portraits was first introduced in the late 1960's. From this time, a number of individuals and organizations worldwide have specialized in providing holographic portraiture services with varying degrees of achievement. Yet today, some 45 years later, holographic portraiture remains an obscure and niche form of displaying an individual's likeness. Despite all of this technology's promising and unique attributes, and the astonishing fact of holography being the most accurate and realistic form of imaging available today; true holographic portraits continues to be a form of portraiture largely unknown to the general public and has never achieved large-scale commercial success. This paper will present a brief history of holographic portraiture, designating the different types of 3-D hologram portraits available today, and their uses. Emphasis will be given to true holographic pulsed portraiture in which the subject itself is recorded holographically using high-energy pulsed lasers. Possible cause and effect for explaining the present demise of this type of portrait making will be discussed along with recent advancements and future developments in this fledgling field which could ultimately lead to a 'tipping point' in large-scale consumer and commercial awareness and desirability of the medium. The author will share his experiences in operating pulsed holographic portraiture studios for over the last 15 years including the vision of a new type of holographic portrait studio for the 21st century which he hopes will attain the level of success enabling a next generation of commercially viable holographic portrait studios for the future.

Radial super-resolution in digital holographic microscopy using structured illumination with circular symmetry

Science.gov (United States)

Yin, Yujian; Su, Ping; Ma, Jianshe

2018-01-01

A method to improve the radial resolution using special structured light is proposed in the field of digital holographic microscopy (DHM). A specimen is illuminated with circular symmetrical structured light that makes the spectrum have radial movement, so that high frequency components of the specimen are moved into the passband of the receiver to overcome the diffraction limit. In the DHM imaging system, Computer Generated Hologram (CGH) technology is used to generate the required structured light grating. Then the grating is loaded into a spatial light modulator (SLM) to obtain specific structured illumination. After recording the hologram, digital reconstruction, for the microstructure of a binary optical element that needs to observe radial distribution, the radial resolution of the specimen is improved experimentally compare it with the result of one-dimensional sinusoidal structured light imaging. And a method of designing structured light is presented.

Demodulation of moire fringes in digital holographic interferometry using an extended Kalman filter.

Science.gov (United States)

Ramaiah, Jagadesh; Rastogi, Pramod; Rajshekhar, Gannavarpu

2018-03-10

This paper presents a method for extracting multiple phases from a single moire fringe pattern in digital holographic interferometry. The method relies on component separation using singular value decomposition and an extended Kalman filter for demodulating the moire fringes. The Kalman filter is applied by modeling the interference field locally as a multi-component polynomial phase signal and extracting the associated multiple polynomial coefficients using the state space approach. In addition to phase, the corresponding multiple phase derivatives can be simultaneously extracted using the proposed method. The applicability of the proposed method is demonstrated using simulation and experimental results.

Implementation of a fast digital optical matrix-vector multiplier using a holographic look-up table and residue arithmetic

Science.gov (United States)

Habiby, Sarry F.; Collins, Stuart A., Jr.

1987-01-01

The design and implementation of a digital (numerical) optical matrix-vector multiplier are presented. A Hughes liquid crystal light valve, the residue arithmetic representation, and a holographic optical memory are used to construct position coded optical look-up tables. All operations are performed in effectively one light valve response time with a potential for a high information density.

Real-time laser holographic interferometry for aerodynamics

International Nuclear Information System (INIS)

Lee, G.

1987-01-01

Recent developments in thermoplastic recording holograms and advancements in automated image digitalization and analysis make real-time laser holographic interferometry feasible for two-dimensional flows such as airfoil flows. Typical airfoil measurements would include airfoil pressure distributions, wake and boundary layer profiles, and flow field density contours. This paper addresses some of the problems and requirements of a real-time laser holographic interferometer. 13 references

A digital long pulse integrator

International Nuclear Information System (INIS)

Broesch, J.D.; Strait, E.J.; Snider, R.T.

1996-10-01

A prototype digital integrator with very long integration capabilities has been developed and field tested on an inductive magnetic sensor on the DIII-D Tokamak. The integrator is being developed for use on ITER with a pulse length of 1000 s, and has direct applications for other long pulse Tokamaks. Inductive magnetic sensors are routinely used on existing Tokamaks, are well understood, and are extremely robust, however, they require integration of the signal to determine the magnetic field strength. The next generation of Tokamaks, will have pulse lengths of 1000 s or longer, require integrators with drift and noise characteristics compatible with the very long pulse lengths. This paper will discuss the architecture, algorithms, and programming of the Long Pulse Integrator (LPI). Of particular interest are the noise control and the built-in offset correction techniques used in this application

High-throughput characterization of film thickness in thin film materials libraries by digital holographic microscopy

International Nuclear Information System (INIS)

Lai Yiuwai; Hofmann, Martin R; Ludwig, Alfred; Krause, Michael; Savan, Alan; Thienhaus, Sigurd; Koukourakis, Nektarios

2011-01-01

A high-throughput characterization technique based on digital holography for mapping film thickness in thin-film materials libraries was developed. Digital holographic microscopy is used for fully automatic measurements of the thickness of patterned films with nanometer resolution. The method has several significant advantages over conventional stylus profilometry: it is contactless and fast, substrate bending is compensated, and the experimental setup is simple. Patterned films prepared by different combinatorial thin-film approaches were characterized to investigate and demonstrate this method. The results show that this technique is valuable for the quick, reliable and high-throughput determination of the film thickness distribution in combinatorial materials research. Importantly, it can also be applied to thin films that have been structured by shadow masking.

High-throughput characterization of film thickness in thin film materials libraries by digital holographic microscopy.

Science.gov (United States)

Lai, Yiu Wai; Krause, Michael; Savan, Alan; Thienhaus, Sigurd; Koukourakis, Nektarios; Hofmann, Martin R; Ludwig, Alfred

2011-10-01

A high-throughput characterization technique based on digital holography for mapping film thickness in thin-film materials libraries was developed. Digital holographic microscopy is used for fully automatic measurements of the thickness of patterned films with nanometer resolution. The method has several significant advantages over conventional stylus profilometry: it is contactless and fast, substrate bending is compensated, and the experimental setup is simple. Patterned films prepared by different combinatorial thin-film approaches were characterized to investigate and demonstrate this method. The results show that this technique is valuable for the quick, reliable and high-throughput determination of the film thickness distribution in combinatorial materials research. Importantly, it can also be applied to thin films that have been structured by shadow masking.

Calibrated Phase-Shifting Digital Holographic Microscope Using a Sampling Moiré Technique

Directory of Open Access Journals (Sweden)

Peng Xia

2018-05-01

Full Text Available A calibrated phase-shifting digital holographic microscope system capable of improving the quality of reconstructed images is proposed. Phase-shifting errors are introduced in phase-shifted holograms for numerous reasons, such as the non-linearity of piezoelectric transducers (PZTs, wavelength fluctuations in lasers, and environmental disturbances, leading to poor-quality reconstructions. In our system, in addition to the camera used to record object information, an extra camera is used to record interferograms, which are used to analyze phase-shifting errors using a sampling Moiré technique. The quality of the reconstructed object images can be improved by the phase-shifting error compensation algorithm. Both the numerical simulation and experiment demonstrate the effectiveness of the proposed system.

Holographic inspection of nuclear plant

International Nuclear Information System (INIS)

Gordon, A.L.; Armour, I.A.; Glanville, R.; Malcolm, G.J.; Wright, D.G.

1988-01-01

The high resolution, enormous depth of field and high tolerance to radiation of holography mean that it has great potential as an inspection tool in the nuclear industry. In addition, the ability of double-pulse holography to yield detailed information on vibration over the whole field of both large and small structures provides measurements that often cannot be obtained in any other way. This paper reviews the development of equipment for the holographic inspection of nuclear fuel elements; a portable holocamera for use inside reactors; and the application of holographic techniques for vibration measurements in a nuclear power station. (author)

Structural properties of liposomes from digital holographic microscopy

Science.gov (United States)

Di Maio, Isabelle L.; Carl, Daniel; Langehanenberg, Patrik; Valenzuela, Stella M.; Battle, Andrew R.; Al Khazaaly, Sabah; Killingsworth, Murray; Kemper, Bjorn; von Bally, Gert; Martin, Donald K.

2006-01-01

We have constructed liposomes from L alpha Phosphatidylcholine (PC) lipids, which are biomimetic lipids similar to those present in the membranes of mammalian cells. We propose an advance in the use of liposomes, such as for drug delivery, to incorporate into the liposomal membranes transport proteins that have been extracted from the lipid membranes of mammalian cells. In this paper, we describe the usage of a novel optical microscope to characterize the nanomechanical properties of these liposomes. We have applied the technique of digital holographic microscopy, using an instrument recently developed at the University of Münster, Germany. This system enabled us to measure quantitatively the structural changes in liposomes. We have investigated the deformations of these biomimetic lipids comprising these liposomes by applying osmotic stresses, in order to gain insight into the membrane environment prior to incorporation of cloned membrane transport proteins. This control of the nanomechanical properties is important in the stresses transmitted to mechanosensitive ion channels that we have incorporated into the liposomal membranes. These liposomes provide transporting vesicles that respond to mechanical stresses, such as those that occur during implantation.

Digital pulse processing: new possibilities in nuclear spectroscopy

International Nuclear Information System (INIS)

Warburton, W.K.; Momayezi, M.; Hubbard-Nelson, B.; Skulski, W.

2000-01-01

Digital pulse processing is a signal processing technique in which detector (preamplifier output) signals are directly digitized and processed to extract quantities of interest. This approach has several significant advantages compared to traditional analog signal shaping. First, analyses can be developed which take pulse-by-pulse differences into account, as in making ballistic deficit compensations. Second, transient induced charge signals, which deposit no net charge on an electrode, can be analyzed to give, for example, information on the position of interaction within the detector. Third, deadtimes from transient overload signals are greatly reduced, from tens of μs to hundreds of ns. Fourth, signals are easily captured, so that more complex analyses can be postponed until the source event has been deemed 'interesting'. Fifth, signal capture and processing may easily be based on coincidence criteria between different detectors or different parts of the same detector. XIAs recently introduced CAMAC module, the DGF-4C, provides many of these features for four input channels, including two levels of digital processing and a FIFO for signal capture for each signal channel. The first level of digital processing is 'immediate', taking place in a gate array at the 40 MHz digitization rate, and implements pulse detection, pileup inspection, trapezoidal energy filtering, and control of an external 25.6 μs long FIFO. The second level of digital processing is provided by a digital signal processor (DSP), where more complex algorithms can be implemented. To illustrate digital pulse processing's possibilities, we describe the application of the DGF-4C to a series of experiments. The first, for which the DGF was originally developed, involves locating gamma-ray interaction sites within large segmented Ge detectors. The goal of this work is to attain spatial resolutions of order 2 mm σ within 70 mm x 90 mm detectors. We show how pulse shape analysis allows ballistic

Holographic storage of three-dimensional image and data using photopolymer and polymer dispersed liquid crystal films

International Nuclear Information System (INIS)

Gao Hong-Yue; Liu Pan; Zeng Chao; Yao Qiu-Xiang; Zheng Zhiqiang; Liu Jicheng; Zheng Huadong; Yu Ying-Jie; Zeng Zhen-Xiang; Sun Tao

2016-01-01

We present holographic storage of three-dimensional (3D) images and data in a photopolymer film without any applied electric field. Its absorption and diffraction efficiency are measured, and reflective analog hologram of real object and image of digital information are recorded in the films. The photopolymer is compared with polymer dispersed liquid crystals as holographic materials. Besides holographic diffraction efficiency of the former is little lower than that of the latter, this work demonstrates that the photopolymer is more suitable for analog hologram and big data permanent storage because of its high definition and no need of high voltage electric field. Therefore, our study proposes a potential holographic storage material to apply in large size static 3D holographic displays, including analog hologram displays, digital hologram prints, and holographic disks. (special topic)

Lensless digital holographic microscopy and its applications in biomedicine and environmental monitoring

KAUST Repository

Wu, Yichen; Ozcan, Aydogan

2017-01-01

Optical compound microscope has been a major tool in biomedical imaging for centuries. Its performance relies on relatively complicated, bulky and expensive lenses and alignment mechanics. In contrast, the lensless microscope digitally reconstructs microscopic images of specimens without using any lenses, as a result of which it can be made much smaller, lighter and lower-cost. Furthermore, the limited space-bandwidth product of objective lenses in a conventional microscope can be significantly surpassed by a lensless microscope. Such lensless imaging designs have enabled high-resolution and high-throughput imaging of specimens using compact, portable and cost-effective devices to potentially address various point-of-care, global-health and telemedicine related challenges. In this review, we discuss the operation principles and the methods behind lensless digital holographic on-chip microscopy. We also go over various applications that are enabled by cost-effective and compact implementations of lensless microscopy, including some recent work on air quality monitoring, which utilized machine learning for high-throughput and accurate quantification of particulate matter in air. Finally, we conclude with a brief future outlook of this computational imaging technology.

Lensless digital holographic microscopy and its applications in biomedicine and environmental monitoring

KAUST Repository

Wu, Yichen

2017-08-31

Optical compound microscope has been a major tool in biomedical imaging for centuries. Its performance relies on relatively complicated, bulky and expensive lenses and alignment mechanics. In contrast, the lensless microscope digitally reconstructs microscopic images of specimens without using any lenses, as a result of which it can be made much smaller, lighter and lower-cost. Furthermore, the limited space-bandwidth product of objective lenses in a conventional microscope can be significantly surpassed by a lensless microscope. Such lensless imaging designs have enabled high-resolution and high-throughput imaging of specimens using compact, portable and cost-effective devices to potentially address various point-of-care, global-health and telemedicine related challenges. In this review, we discuss the operation principles and the methods behind lensless digital holographic on-chip microscopy. We also go over various applications that are enabled by cost-effective and compact implementations of lensless microscopy, including some recent work on air quality monitoring, which utilized machine learning for high-throughput and accurate quantification of particulate matter in air. Finally, we conclude with a brief future outlook of this computational imaging technology.

Developments in holographic-based scanner designs

Science.gov (United States)

Rowe, David M.

1997-07-01

Holographic-based scanning systems have been used for years in the high resolution prepress markets where monochromatic lasers are generally utilized. However, until recently, due to the dispersive properties of holographic optical elements (HOEs), along with the high cost associated with recording 'master' HOEs, holographic scanners have not been able to penetrate major scanning markets such as the laser printer and digital copier markets, low to mid-range imagesetter markets, and the non-contact inspection scanner market. Each of these markets has developed cost effective laser diode based solutions using conventional scanning approaches such as polygon/f-theta lens combinations. In order to penetrate these markets, holographic-based systems must exhibit low cost and immunity to wavelength shifts associated with laser diodes. This paper describes recent developments in the design of holographic scanners in which multiple HOEs, each possessing optical power, are used in conjunction with one curved mirror to passively correct focal plane position errors and spot size changes caused by the wavelength instability of laser diodes. This paper also describes recent advancements in low cost production of high quality HOEs and curved mirrors. Together these developments allow holographic scanners to be economically competitive alternatives to conventional devices in every segment of the laser scanning industry.

Detection of hidden stationary deformations of vibrating surfaces by use of time-averaged digital holographic interferometry.

Science.gov (United States)

Demoli, Nazif; Vukicevic, Dalibor

2004-10-15

A method of detecting displacements of a surface from its steady-state position to its equilibrium position while it is vibrating has been developed by use of time-average digital holographic interferometry. This method permits extraction of such a hidden deformation by creating two separated systems of interferogram fringes: one corresponding to a time-varying resonantly oscillating optical phase, the other to the stationary phase modification. A mathematical description of the method and illustrative results of experimental verification are presented.

Evaluation of diffuse-illumination holographic cinematography in a flutter cascade

Science.gov (United States)

Decker, A. J.

1986-01-01

Since 1979, the Lewis Research Center has examined holographic cinematography for three-dimensional flow visualization. The Nd:YAG lasers used were Q-switched, double-pulsed, and frequency-doubled, operating at 20 pulses per second. The primary subjects for flow visualization were the shock waves produced in two flutter cascades. Flow visualization was by diffuse-illumination, double-exposure, and holographic interferometry. The performances of the lasers, holography, and diffuse-illumination interferometry are evaluated in single-window wind tunnels. The fringe-contrast factor is used to evaluate the results. The effects of turbulence on shock-wave visualization in a transonic flow are discussed. The depth of field for visualization of a turbulent structure is demonstrated to be a measure of the relative density and scale of that structure. Other items discussed are the holographic emulsion, tests of coherence and polarization, effects of windows and diffusers, hologram bleaching, laser configurations, influence and handling of specular reflections, modes of fringe localization, noise sources, and coherence requirements as a function of the pulse energy. Holography and diffuse illumination interferometry are also reviewed.

Digital hologram transformations for RGB color holographic display with independent image magnification and translation in 3D.

Science.gov (United States)

Makowski, Piotr L; Zaperty, Weronika; Kozacki, Tomasz

2018-01-01

A new framework for in-plane transformations of digital holograms (DHs) is proposed, which provides improved control over basic geometrical features of holographic images reconstructed optically in full color. The method is based on a Fourier hologram equivalent of the adaptive affine transformation technique [Opt. Express18, 8806 (2010)OPEXFF1094-408710.1364/OE.18.008806]. The solution includes four elementary geometrical transformations that can be performed independently on a full-color 3D image reconstructed from an RGB hologram: (i) transverse magnification; (ii) axial translation with minimized distortion; (iii) transverse translation; and (iv) viewing angle rotation. The independent character of transformations (i) and (ii) constitutes the main result of the work and plays a double role: (1) it simplifies synchronization of color components of the RGB image in the presence of mismatch between capture and display parameters; (2) provides improved control over position and size of the projected image, particularly the axial position, which opens new possibilities for efficient animation of holographic content. The approximate character of the operations (i) and (ii) is examined both analytically and experimentally using an RGB circular holographic display system. Additionally, a complex animation built from a single wide-aperture RGB Fourier hologram is presented to demonstrate full capabilities of the developed toolset.

Demonstration of holographic smart card system using the optical memory technology

Science.gov (United States)

Kim, JungHoi; Choi, JaeKwang; An, JunWon; Kim, Nam; Lee, KwonYeon; Jeon, SeckHee

2003-05-01

In this paper, we demonstrate the holographic smart card system using digital holographic memory technique that uses reference beam encrypted by the random phase mask to prevent unauthorized users from accessing the stored digital page. The input data that include document data, a picture of face, and a fingerprint for identification is encoded digitally and then coupled with the reference beam modulated by a random phase mask. Therefore, this proposed system can execute recording in the order of MB~GB and readout all personal information from just one card without any additional database system. Also, recorded digital holograms can't be reconstructed without a phase key and can't be copied by using computers, scanners, or photography.

Correction of phase-shifting error in wavelength scanning digital holographic microscopy

Science.gov (United States)

Zhang, Xiaolei; Wang, Jie; Zhang, Xiangchao; Xu, Min; Zhang, Hao; Jiang, Xiangqian

2018-05-01

Digital holographic microscopy is a promising method for measuring complex micro-structures with high slopes. A quasi-common path interferometric apparatus is adopted to overcome environmental disturbances, and an acousto-optic tunable filter is used to obtain multi-wavelength holograms. However, the phase shifting error caused by the acousto-optic tunable filter reduces the measurement accuracy and, in turn, the reconstructed topographies are erroneous. In this paper, an accurate reconstruction approach is proposed. It corrects the phase-shifting errors by minimizing the difference between the ideal interferograms and the recorded ones. The restriction on the step number and uniformity of the phase shifting is relaxed in the interferometry, and the measurement accuracy for complex surfaces can also be improved. The universality and superiority of the proposed method are demonstrated by practical experiments and comparison to other measurement methods.

Pulsed TV holography measurement and digital reconstruction of compression acoustic wave fields: application to nondestructive testing of thick metallic samples

International Nuclear Information System (INIS)

Trillo, C; Doval, A F; Deán-Ben, X L; López-Vázquez, J C; Fernández, J L; Hernández-Montes, S

2011-01-01

This paper describes a technique that numerically reconstructs the complex acoustic amplitude (i.e. the acoustic amplitude and phase) of a compression acoustic wave in the interior volume of a specimen from a set of full-field optical measurements of the instantaneous displacement of the surface. The volume of a thick specimen is probed in transmission mode by short bursts of narrowband compression acoustic waves generated at one of its faces. The temporal evolution of the displacement field induced by the bursts emerging at the opposite surface is measured by pulsed digital holographic interferometry (pulsed TV holography). A spatio-temporal 3D Fourier transform processing of the measured data yields the complex acoustic amplitude at the plane of the surface as a sequence of 2D complex-valued maps. Finally, a numerical implementation of the Rayleigh–Sommerfeld diffraction formula is employed to reconstruct the complex acoustic amplitude at other planes in the interior volume of the specimen. The whole procedure can be regarded as a combination of optical digital holography and acoustical holography methods. The technique was successfully tested on aluminium specimens with and without an internal artificial defect and sample results are presented. In particular, information about the shape and position of the defect was retrieved in the experiment performed on the flawed specimen, which indicates the potential applicability of the technique for the nondestructive testing of materials

Digital implementation of the preloaded filter pulse processor

International Nuclear Information System (INIS)

Westphal, G.P.; Cadek, G.R.; Keroe, N.; Sauter, TH.; Thorwartl, P.C.

1995-01-01

Adapting it's processing time to the respective pulse intervals, the Preloaded Filter (PLF) pulse processor offers optimum resolution together with highest possible throughput rates. The PLF algorithm could be formulated in a recursive manner which made possible it's implementation by means of a large field-programmable gate array, as a fast, pipe-lined digital processor with 10 MHz maximum throughput rate. While pre-filter digitization by an ADC with 12 bit resolution and 10M Hz sampling rate resulted in a poorer resolution than that of an analog filter, a digital PLF based on an ADC with 14 bit resolution and 10 MHz sampling rate, surpassed high-quality analog filters in resolution, throughput rate and long-term stability. (author) 6 refs.; 7 figs

Digital pulse-shape analyzer based on fast sampling of an integrated charge pulse

International Nuclear Information System (INIS)

Jordanov, V.T.; Knoll, G.F.

1995-01-01

A novel configuration for pulse-shape analysis and discrimination has been developed. The current pulse from detector is sent to a gated integrator and then sampled by a flash analog-to-digital converter (ADC). The sampled data are processed digitally, thus allowing implementation of a near-optimum weighting function and elimination some of the instabilities associated with the gated integrator. The analyzer incorporates pileup rejection circuit that reduces the pileup effects at high counting rates. The system was tested liquid scintillator. Figures of merit for neutron-gamma pulse-shape discrimination were found to be: 0.78 for 25 keV (electron equivalent energy) and 3.5 for 500 keV. The technique described in this paper was developed to be used in a near tissue-equivalent neutron-gamma dosimeter which employs a liquid scintillator detector

Ultra-fast facial topometry using pulsed holography

Science.gov (United States)

Thelen, Andrea; Frey, Susanne; Hirsch, Sven; Ladrière, Natalie; Hering, Peter

2006-02-01

For planning, simulation and documentation of interventions in maxillofacial surgery high resolving soft tissue information of the human face in upright position is needed. This information can be gained by holographic methods, which allow a recording of the whole face in an extremely short time period, so that no movement artefacts occur. The hologram is recorded with a single laser pulse of 25 ns duration and stored in photosensitive material. After automated wet-chemical processing, the hologram is optically reconstructed with a cw-laser. During the optical reconstruction, a light field, which is a one-to-one three-dimensional representation of the recorded face, emerges at its original position and is digitized into a set of two-dimensional projections. Digital image processing leads to merging of these projections into a three-dimensional computer model. Besides the topometric information, a high resolving pixel precise texture is also extracted from the holographic reconstruction and used for the texturing of the computer models. The use of mirrors allows the simultaneous recording of three different views of the face with one laser pulse. The three different views of the face can be combined easily, because they are simultaneously recorded. Thus a recording range of approximately 270 degrees is achieved. In addition to the medical application, high resolving and textured computer models of faces are of tremendous importance for facial reconstruction in anthropology, forensic science and archaeology.

High efficiency and flexible working distance digital in-line holographic microscopy based on Fresnel zone plate

International Nuclear Information System (INIS)

Tian, Peng; Yang, Fan; Li, Fanxing; Hu, Song; Yan, Wei; Hua, Yilei

2017-01-01

Traditional digital in-line holography suffers from twin-image noise problems and extremely short working distances between the object and light source. Here, we propose lensless Fourier transform digital in-line holographic microscopy based on a single optical element. A Fresnel zone plate is used to split the incident light into two parts: one is scattered along the original direction, the other is gathered at a focal point and the sample is put behind the focus. The interference fringe pattern, formed by the two beams, is recorded digitally by a CCD camera. A novel reconstruction algorithm is proposed to present the object image. The proof-of-concept experiments demonstrate that the proposed technique can eliminate the twin-image noise problem, improving the image contrast with high efficiency, and increasing the flexibility of the working distance. Furthermore, a wide field of view and no contact make it a promising tool for the study of materials science, biology and microelectronics. (paper)

Study of resolution and linearity in LaBr3: Ce scintillator through digital-pulse processing

International Nuclear Information System (INIS)

Abhinav Kumar; Mishra, Gaurav; Ramachandran, K.

2014-01-01

Advent of digital pulse processing has led to a paradigm shift in pulse processing techniques by replacing analog electronics processing chain with equivalent algorithms acting on pulse profiles digitized at high sampling rates. In this paper, we have carried out offline digital pulse processing of Cerium-doped Lanthanum bromide scintillator (LaBr 3 : Ce) detector pulses, acquired using CAEN V1742 VME digitizer module. Algorithms have been written to approximate the functioning of peak sensing analog-to-digital convertor (ADC) and charge-to-digital convertor (QDC). Energy dependence of resolution and energy linearity of LaBr 3 : Ce scintillator detector has been studied by utilizing aforesaid algorithms

Pulse shape discrimination with fast digitizers

International Nuclear Information System (INIS)

Cester, D.; Lunardon, M.; Nebbia, G.; Stevanato, L.; Viesti, G.; Petrucci, S.; Tintori, C.

2014-01-01

The pulse shape discrimination (PSD) between neutrons and gamma rays in liquid scintillators is studied by using the charge integration method with fast digitizers having different technical characteristics. The use of the Figure of Merit (FoM) to verify the PSD capability is discussed. The dependence of the FoM on the digitizer sampling rate and resolution is experimentally determined. The effects due to the type of source and the irradiation geometry are also evidenced and discussed

Digital pulse processing in Mössbauer spectroscopy

Science.gov (United States)

Veiga, A.; Grunfeld, C. M.

2014-04-01

In this work we present some advances towards full digitization of the detection subsystem of a Mössbauer transmission spectrometer. We show how, using adequate instrumentation, preamplifier output of a proportional counter can be digitized with no deterioration in spectrum quality, avoiding the need of a shaping amplifier. A pipelined architecture is proposed for a digital processor, which constitutes a versatile platform for the development of pulse processing techniques. Requirements for minimization of the analog processing are considered and experimental results are presented.

Lensless digital holographic microscopy and its applications in biomedicine and environmental monitoring.

Science.gov (United States)

Wu, Yichen; Ozcan, Aydogan

2018-03-01

Optical compound microscope has been a major tool in biomedical imaging for centuries. Its performance relies on relatively complicated, bulky and expensive lenses and alignment mechanics. In contrast, the lensless microscope digitally reconstructs microscopic images of specimens without using any lenses, as a result of which it can be made much smaller, lighter and lower-cost. Furthermore, the limited space-bandwidth product of objective lenses in a conventional microscope can be significantly surpassed by a lensless microscope. Such lensless imaging designs have enabled high-resolution and high-throughput imaging of specimens using compact, portable and cost-effective devices to potentially address various point-of-care, global-health and telemedicine related challenges. In this review, we discuss the operation principles and the methods behind lensless digital holographic on-chip microscopy. We also go over various applications that are enabled by cost-effective and compact implementations of lensless microscopy, including some recent work on air quality monitoring, which utilized machine learning for high-throughput and accurate quantification of particulate matter in air. Finally, we conclude with a brief future outlook of this computational imaging technology. Copyright © 2017 Elsevier Inc. All rights reserved.

Digital baseline estimation method for multi-channel pulse height analyzing

International Nuclear Information System (INIS)

Xiao Wuyun; Wei Yixiang; Ai Xianyun

2005-01-01

The basic features of digital baseline estimation for multi-channel pulse height analysis are introduced. The weight-function of minimum-noise baseline filter is deduced with functional variational calculus. The frequency response of this filter is also deduced with Fourier transformation, and the influence of parameters on amplitude frequency response characteristics is discussed. With MATLAB software, the noise voltage signal from the charge sensitive preamplifier is simulated, and the processing effect of minimum-noise digital baseline estimation is verified. According to the results of this research, digital baseline estimation method can estimate baseline optimally, and it is very suitable to be used in digital multi-channel pulse height analysis. (authors)

Digital pulse processor for ion beam microprobe imaging

International Nuclear Information System (INIS)

Bogovac, M.; Jaksic, M.; Wegrzynek, D.; Markowicz, A.

2009-01-01

Capabilities of spectroscopic ion beam analysis (IBA) techniques that are available in ion microprobe facilities can be greatly improved by the use of digital pulse processing. We report here development of a digital multi parameter data acquisition system suitable for IBA imaging applications. Input signals from charge sensitive preamplifier are conditioned by using a simple circuit and digitized with fast ADCs. The digitally converted signals are processed in real time using FPGA. Implementation of several components of the system is presented.

Gastrointestinal digital fluoroscopy: Comparison of digital pulsed progressive readout images with 100-mm spot films

International Nuclear Information System (INIS)

Steiner, E.; Ferrucci, J.T.; Mueller, P.R.; Hahn, P.F.

1987-01-01

New developments in pulsed progressive readout (PPR) techniques allow short, extremely intense pulses of radiation to be used to produce a latent image which is then progressively read off the video camera and placed in 1,024 x 1,024-pixel digital storage. The resulting image is produced by a 10-20-msec pulse, reducing motion artifact to below that achievable with conventional spot film techniques, with a potential for 50%-95% dose reduction. This technique of reducing motion artifact is ideal for digital applications in gastrointestinal radiology. The authors compared 10-mm spot films and PPR digital radiographs of 86 anatomic regions in 43 patients undergoing routine barium enema and cholangiographic examinations. Parameters evaluated included display of normal and pathologic features, image contrast, and resolution. The benefits of the PPR technique include postprocessing to evaluate low contrast region and the potential for significant dose reduction

Pulse discrimination of background and gamma-ray source by digital pulse shape discrimination in a BF3 detector

International Nuclear Information System (INIS)

Kim, Jinhyung; Kim, J. H.; Choi, H. D.

2014-01-01

As a representative method of non-destructive assay, accurate neutron measurement is difficult due to large background radiation such as γ-ray, secondary radiation, spurious pulse, etc. In a BF 3 detector, the process of signal generation is different between neutron and other radiations. As the development of detection technique, all of signal data can be digitized by digital measurement method. In the previous study, Applied Nuclear Physics Group in Seoul National University has developed digital Pulse Shape Discrimination (PSD) method using digital oscilloscope. In this study, optimization of parameters for pulse discrimination is discussed and γ-ray region is determined by measuring 60 Co source. The background signal of BF 3 detector is discriminated by digital PSD system. Parameters for PSD are optimized through FOM calculation. And the γ-ray region is determined by measuring 60 Co source. In the future, the performance of developed system will be tested in low and high intensity neutron field

Portable pulsed X-ray digital radiographic system based on network transmission

International Nuclear Information System (INIS)

Tang Le; Li Yuanjing; Wang Yi; Cheng Jianping

2004-01-01

Network communication technology of TCP/IP protocol serves as application in pulse X-ray digital radiography system. The system radiographs synchronously with pulse X-ray and converts image signals to digital data, which are transmitted to computer for displaying and processing in network. The system composing structures are present and portable and other characteristics are introduced. (authors)

Chirped pulse digital holography for measuring the sequence of ultrafast optical wavefronts

Science.gov (United States)

Karasawa, Naoki

2018-04-01

Optical setups for measuring the sequence of ultrafast optical wavefronts using a chirped pulse as a reference wave in digital holography are proposed and analyzed. In this method, multiple ultrafast object pulses are used to probe the temporal evolution of ultrafast phenomena and they are interfered with a chirped reference wave to record a digital hologram. Wavefronts at different times can be reconstructed separately from the recorded hologram when the reference pulse can be treated as a quasi-monochromatic wave during the pulse width of each object pulse. The feasibility of this method is demonstrated by numerical simulation.

Implementation of a digital optical matrix-vector multiplier using a holographic look-up table and residue arithmetic

Science.gov (United States)

Habiby, Sarry F.

1987-01-01

The design and implementation of a digital (numerical) optical matrix-vector multiplier are presented. The objective is to demonstrate the operation of an optical processor designed to minimize computation time in performing a practical computing application. This is done by using the large array of processing elements in a Hughes liquid crystal light valve, and relying on the residue arithmetic representation, a holographic optical memory, and position coded optical look-up tables. In the design, all operations are performed in effectively one light valve response time regardless of matrix size. The features of the design allowing fast computation include the residue arithmetic representation, the mapping approach to computation, and the holographic memory. In addition, other features of the work include a practical light valve configuration for efficient polarization control, a model for recording multiple exposures in silver halides with equal reconstruction efficiency, and using light from an optical fiber for a reference beam source in constructing the hologram. The design can be extended to implement larger matrix arrays without increasing computation time.

Volume holographic storage and multiplexing in blends of PMMA and a block methacrylic azopolymer, using 488 nm light pulses in the range of 100 ms to 1 s

DEFF Research Database (Denmark)

Forcen, Patricia; Oriol, Luis; Sanchez, Carlos

2008-01-01

Blends of polymethylmethacrylate (PMMA) and diblock methacrylic azopolymers have been investigated for holographic storage with short light pulses. Transmission electron microscopy measurements show that the dilution of the block copolymer in PMMA changes the microstructure from a lamellar to a s...

Deriving Particle Distributions from In-Line Fraunhofer Holographic Data

International Nuclear Information System (INIS)

Ciarcia, C.A.; Johnson, D.E.; Sorenson, D.S.; Frederickson, R.H.; Delanoy, A.D.; Malone, R.M.; Tunnel, T.W.

1997-01-01

Holographic data are acquired during hydrodynamic experiments at the Pegasus Pulsed Power Facility at the Los Alamos National Laboratory. These experiments produce a fine spray of fast-moving particles. Snapshots of the spray are captured using in-line Fraunhofer holographic techniques. Roughly one cubic centimeter is recorded by the hologram. Minimum detectable particle size in the data extends down to 2 microns. In a holography reconstruction system, a laser illuminates the hologram as it rests in a three-axis actuator, recreating the snapshot of the experiment. A computer guides the actuators through an orderly sequence programmed by the user. At selected intervals, slices of this volume are captured and digitized with a CCD camera. Intermittent on-line processing of the image data and computer control of the camera functions optimizes statistics of the acquired image data for off-line processing. Tens of thousands of individual data frames (30 to 40 gigabytes of data) are required to recreate a digital representation of the snapshot. Throughput of the reduction system is 550 megabytes per hour (MB/hr). Objects and associated features from the data are subsequently extracted during off-line processing. Discrimination and correlation tests reject noise, eliminate multiple counting of particles, and build an error model to estimate performance. Objects surviving these tests are classified as particles. The particle distributions are derived from the data base formed by these particles, their locations and features. Throughput of the off-line processing exceeds 500 MB/hr. This paper describes the reduction system, outlines the off-line processing procedure, summarizes the discrimination and correlation tests, and reports numerical results for a sample data set

Parallel computing of a digital hologram and particle searching for microdigital-holographic particle-tracking velocimetry

International Nuclear Information System (INIS)

Satake, Shin-ichi; Kanamori, Hiroyuki; Kunugi, Tomoaki; Sato, Kazuho; Ito, Tomoyoshi; Yamamoto, Keisuke

2007-01-01

We have developed a parallel algorithm for microdigital-holographic particle-tracking velocimetry. The algorithm is used in (1) numerical reconstruction of a particle image computer using a digital hologram, and (2) searching for particles. The numerical reconstruction from the digital hologram makes use of the Fresnel diffraction equation and the FFT (fast Fourier transform),whereas the particle search algorithm looks for local maximum graduation in a reconstruction field represented by a 3D matrix. To achieve high performance computing for both calculations (reconstruction and particle search), two memory partitions are allocated to the 3D matrix. In this matrix, the reconstruction part consists of horizontally placed 2D memory partitions on the x-y plane for the FFT, whereas, the particle search part consists of vertically placed 2D memory partitions set along the z axes.Consequently, the scalability can be obtained for the proportion of processor elements,where the benchmarks are carried out for parallel computation by a SGI Altix machine

Analysis of pulse-shape discrimination techniques for BC501A using GHz digital signal processing

International Nuclear Information System (INIS)

Rooney, B.D.; Dinwiddie, D.R.; Nelson, M.A.; Rawool-Sullivan, Mohini W.

2001-01-01

A comparison study of pulse-shape analysis techniques was conducted for a BC501A scintillator using digital signal processing (DSP). In this study, output signals from a preamplifier were input directly into a 1 GHz analog-to-digital converter. The digitized data obtained with this method was post-processed for both pulse-height and pulse-shape information. Several different analysis techniques were evaluated for neutron and gamma-ray pulse-shape discrimination. It was surprising that one of the simplest and fastest techniques resulted in some of the best pulse-shape discrimination results. This technique, referred to here as the Integral Ratio technique, was able to effectively process several thousand detector pulses per second. This paper presents the results and findings of this study for various pulse-shape analysis techniques with digitized detector signals.

Spatially and temporally resolved diagnostics of dense sprays using gated, femtosecond, digital holography

Science.gov (United States)

Trolinger, James D.; Dioumaev, Andrei K.; Ziaee, Ali; Minniti, Marco; Dunn-Rankin, Derek

2017-08-01

This paper describes research that demonstrated gated, femtosecond, digital holography, enabling 3D microscopic viewing inside dense, almost opaque sprays, and providing a new and powerful diagnostics capability for viewing fuel atomization processes never seen before. The method works by exploiting the extremely short coherence and pulse length (approximately 30 micrometers in this implementation) provided by a femtosecond laser combined with digital holography to eliminate multiple and wide angle scattered light from particles surrounding the injection region, which normally obscures the image of interest. Photons that follow a path that differs in length by more than 30 micrometers from a straight path through the field to the sensor do not contribute to the holographic recording of photons that travel in a near straight path (ballistic and "snake" photons). To further enhance the method, off-axis digital holography was incorporated to enhance signal to noise ratio and image processing capability in reconstructed images by separating the conjugate images, which overlap and interfere in conventional in-line holography. This also enables digital holographic interferometry. Fundamental relationships and limitations were also examined. The project is a continuing collaboration between MetroLaser and the University of California, Irvine.

Acoustic emission linear pulse holography

Science.gov (United States)

Collins, H.D.; Busse, L.J.; Lemon, D.K.

1983-10-25

This device relates to the concept of and means for performing Acoustic Emission Linear Pulse Holography, which combines the advantages of linear holographic imaging and Acoustic Emission into a single non-destructive inspection system. This unique system produces a chronological, linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. The innovation is the concept of utilizing the crack-generated acoustic emission energy to generate a chronological series of images of a growing crack by applying linear, pulse holographic processing to the acoustic emission data. The process is implemented by placing on a structure an array of piezoelectric sensors (typically 16 or 32 of them) near the defect location. A reference sensor is placed between the defect and the array.

Review of quantitative phase-digital holographic microscopy: promising novel imaging technique to resolve neuronal network activity and identify cellular biomarkers of psychiatric disorders

KAUST Repository

Marquet, Pierre

2014-09-22

Quantitative phase microscopy (QPM) has recently emerged as a new powerful quantitative imaging technique well suited to noninvasively explore a transparent specimen with a nanometric axial sensitivity. In this review, we expose the recent developments of quantitative phase-digital holographic microscopy (QP-DHM). Quantitative phase-digital holographic microscopy (QP-DHM) represents an important and efficient quantitative phase method to explore cell structure and dynamics. In a second part, the most relevant QPM applications in the field of cell biology are summarized. A particular emphasis is placed on the original biological information, which can be derived from the quantitative phase signal. In a third part, recent applications obtained, with QP-DHM in the field of cellular neuroscience, namely the possibility to optically resolve neuronal network activity and spine dynamics, are presented. Furthermore, potential applications of QPM related to psychiatry through the identification of new and original cell biomarkers that, when combined with a range of other biomarkers, could significantly contribute to the determination of high risk developmental trajectories for psychiatric disorders, are discussed.

Single beam Fourier transform digital holographic quantitative phase microscopy

Energy Technology Data Exchange (ETDEWEB)

Anand, A., E-mail: arun-nair-in@yahoo.com; Chhaniwal, V. K.; Mahajan, S.; Trivedi, V. [Optics Laboratory, Applied Physics Department, Faculty of Technology and Engineering, M.S. University of Baroda, Vadodara 390001 (India); Faridian, A.; Pedrini, G.; Osten, W. [Institut für Technische Optik, Universität Stuttgart, Pfaffenwaldring 9, 70569 Stuttgart (Germany); Dubey, S. K. [Siemens Technology and Services Pvt. Ltd, Corporate Technology—Research and Technology Centre, Bangalore 560100 (India); Javidi, B. [Department of Electrical and Computer Engineering, U-4157, University of Connecticut, Storrs, Connecticut 06269-2157 (United States)

2014-03-10

Quantitative phase contrast microscopy reveals thickness or height information of a biological or technical micro-object under investigation. The information obtained from this process provides a means to study their dynamics. Digital holographic (DH) microscopy is one of the most used, state of the art single-shot quantitative techniques for three dimensional imaging of living cells. Conventional off axis DH microscopy directly provides phase contrast images of the objects. However, this process requires two separate beams and their ratio adjustment for high contrast interference fringes. Also the use of two separate beams may make the system more vulnerable to vibrations. Single beam techniques can overcome these hurdles while remaining compact as well. Here, we describe the development of a single beam DH microscope providing whole field imaging of micro-objects. A hologram of the magnified object projected on to a diffuser co-located with a pinhole is recorded with the use of a commercially available diode laser and an arrayed sensor. A Fourier transform of the recorded hologram directly yields the complex amplitude at the image plane. The method proposed was investigated using various phase objects. It was also used to image the dynamics of human red blood cells in which sub-micrometer level thickness variation were measurable.

Development of an optoelectronic holographic platform for otolaryngology applications

Science.gov (United States)

Harrington, Ellery; Dobrev, Ivo; Bapat, Nikhil; Flores, Jorge Mauricio; Furlong, Cosme; Rosowski, John; Cheng, Jeffery Tao; Scarpino, Chris; Ravicz, Michael

2010-08-01

In this paper, we present advances on our development of an optoelectronic holographic computing platform with the ability to quantitatively measure full-field-of-view nanometer-scale movements of the tympanic membrane (TM). These measurements can facilitate otologists' ability to study and diagnose hearing disorders in humans. The holographic platform consists of a laser delivery system and an otoscope. The control software, called LaserView, is written in Visual C++ and handles communication and synchronization between hardware components. It provides a user-friendly interface to allow viewing of holographic images with several tools to automate holography-related tasks and facilitate hardware communication. The software uses a series of concurrent threads to acquire images, control the hardware, and display quantitative holographic data at video rates and in two modes of operation: optoelectronic holography and lensless digital holography. The holographic platform has been used to perform experiments on several live and post-mortem specimens, and is to be deployed in a medical research environment with future developments leading to its eventual clinical use.

New approaches for the analysis of confluent cell layers with quantitative phase digital holographic microscopy

Science.gov (United States)

Pohl, L.; Kaiser, M.; Ketelhut, S.; Pereira, S.; Goycoolea, F.; Kemper, Björn

2016-03-01

Digital holographic microscopy (DHM) enables high resolution non-destructive inspection of technical surfaces and minimally-invasive label-free live cell imaging. However, the analysis of confluent cell layers represents a challenge as quantitative DHM phase images in this case do not provide sufficient information for image segmentation, determination of the cellular dry mass or calculation of the cell thickness. We present novel strategies for the analysis of confluent cell layers with quantitative DHM phase contrast utilizing a histogram based-evaluation procedure. The applicability of our approach is illustrated by quantification of drug induced cell morphology changes and it is shown that the method is capable to quantify reliable global morphology changes of confluent cell layers.

Study of general digital DC/pulse neutron generator

International Nuclear Information System (INIS)

Li Gang; Liu Zheng; Li Wensheng; Liu Hanlin; Liu Linmao

2014-01-01

Preliminary experimental results of digital DC/pulse neutron generator based on a ceramic drive-in target neutron tube for explosives detection are presented. The generator is a portable and on-off neutron source, and it can be controlled by remote PC. The generator can produce DC neutrons, pulse neutrons and multiple pulse neutrons. The maximum neutron yield is about 2 × 10"8 n/s, the minimum pulse width is 10 μs and the maximum pulse frequency is 10 kHz. Neutron yield and time-spectrum is measured in China Academy of Engineering Physics. The generator is suitable for explosive detection with PFTNA technology, and it can be used in other areas such as reactor measurements and on-line industrial test systems. (authors)

Phase-shifting Real-time Holographic Microscopy applied in micro-structures surface analysis

International Nuclear Information System (INIS)

Brito, I V; Gesualdi, M R R; Muramatsu, M; Ricardo, J

2011-01-01

The microscopic real-time analysis of micro structured materials is of great importance in various domains of science and technology. For other hand, the holographic interferometry comprises a group of powerful optical methods for non-destructive testing in surface analysis. The holographic microscopy uses the holographic interferometric techniques to obtain quantitative intensity and phase information of the optical waves by microscopic systems. With the development of CCD cameras, computers (hardware and software), and new materials for holographic recording, these techniques can be used to replace the classical form of registration and became promising tools in surface analysis. In this work, we developed a prototype of Photorefractive and Digital Holographic Microscope for real-time analysis of micro-structured systems based on the phase-shifting real-time holographic interferometry techniques. Using this apparatus, we are made analysis of shapes and surfaces to obtain the phase maps and the 3D profiles of some samples.

In situ visualizing the evolution of the light-induced refractive index change of Mn:KLTN crystal with digital holographic interferometry

Directory of Open Access Journals (Sweden)

Jinxin Han

2015-04-01

Full Text Available The light-induced refractive index change in Mn:KLTN crystal, illuminated by focused light sheet, is visualized in situ and quantified by digital holographic interferometry. By numerically retrieving a series of sequential phase maps from recording digital holograms, the spatial distribution of the induced refractive index change can be visualized and estimated readily. This technique enables the observation of the temporal evolution of the refractive index change under different recording situations such as writing laser power, applied voltage, and temperature, and the photoconductivity of Mn:KLTN crystal can be calculated as well, the experimental results are in good agreement with the theory. The research results suggest that the presented method is successful and feasible.

Study of time-domain digital pulse shaping algorithms for nuclear signals

International Nuclear Information System (INIS)

Zhou Jianbin; Tuo Xianguo; Zhu Xing; Liu Yi; Zhou Wei; Lei Jiarong

2012-01-01

With the development on high-speed integrated circuit, fast high resolution sampling ADC and digital signal processors are replacing analog shaping amplifier circuit. This paper firstly presents the numerical analysis and simulation on R-C shaping circuit model and C-R shaping circuit model. Mathematic models are established based on 1 st order digital differential method and Kirchhoff Current Law in time domain, and a simulation and error evaluation experiment on an ideal digital signal are carried out with Excel VBA. A digital shaping test for a semiconductor X-ray detector in real time is also presented. Then a numerical analysis for Sallen-Key(S-K) low-pass filter circuit model is implemented based on the analysis of digital R-C and digital C-R shaping methods. By applying the 2 nd order non-homogeneous differential equation,the authors implement a digital Gaussian filter model for a standard exponential-decaying signal and a nuclear pulse signal. Finally, computer simulations and experimental tests are carried out and the results show the possibility of the digital pulse processing algorithms. (authors)

Micro patterned surfaces: an effective tool for long term digital holographic microscopy cell imaging

Science.gov (United States)

Mues, Sarah; Lilge, Inga; Schönherr, Holger; Kemper, Björn; Schnekenburger, Jürgen

2017-02-01

The major problem of Digital Holographic Microscopy (DHM) long term live cell imaging is that over time most of the tracked cells move out of the image area and other ones move in. Therefore, most of the cells are lost for the evaluation of individual cellular processes. Here, we present an effective solution for this crucial problem of long-term microscopic live cell analysis. We have generated functionalized slides containing areas of 250 μm per 200 μm. These micropatterned biointerfaces consist of passivating polyaclrylamide brushes (PAAm). Inner areas are backfilled with octadecanthiol (ODT), which allows cell attachment. The fouling properties of these surfaces are highly controllable and therefore the defined areas designed for the size our microscopic image areas were effective in keeping all cells inside the rectangles over the selected imaging period.

Probing interaction and spatial curvature in the holographic dark energy model

International Nuclear Information System (INIS)

Li, Miao; Li, Xiao-Dong; Wang, Shuang; Wang, Yi; Zhang, Xin

2009-01-01

In this paper we place observational constraints on the interaction and spatial curvature in the holographic dark energy model. We consider three kinds of phenomenological interactions between holographic dark energy and matter, i.e., the interaction term Q is proportional to the energy densities of dark energy (ρ Λ ), matter (ρ m ), and matter plus dark energy (ρ m +ρ Λ ). For probing the interaction and spatial curvature in the holographic dark energy model, we use the latest observational data including the type Ia supernovae (SNIa) Constitution data, the shift parameter of the cosmic microwave background (CMB) given by the five-year Wilkinson Microwave Anisotropy Probe (WMAP5) observations, and the baryon acoustic oscillation (BAO) measurement from the Sloan Digital Sky Survey (SDSS). Our results show that the interaction and spatial curvature in the holographic dark energy model are both rather small. Besides, it is interesting to find that there exists significant degeneracy between the phenomenological interaction and the spatial curvature in the holographic dark energy model

Digital pulse processing techniques for high resolution amplitude measurement of radiation detector

International Nuclear Information System (INIS)

Singhai, P.; Roy, A.; Dhara, P.; Chatterjee, S.

2012-01-01

The digital pulse processing techniques for high resolution amplitude measurement of radiation detector pulse is an effective replacement of expensive and bulky analog processing as the digital domain offers higher channel density and at the same time it is cheaper. We have demonstrated a prototype digital setup with highspeed sampling ADC with sampling frequency of 80-125 MHz followed by series of IIR filters for pulse shaping in a trigger-less acquisition mode. The IIR filters, peak detection algorithm and the data write-out logic was written on VHDL and implemented on FPGA. We used CAMAC as the read out platform. In conjunction with the full hardware implementation we also used a mixed platform with VME digitizer card with raw-sample read out using C code. The rationale behind this mixed platform is to test out various filter algorithms quickly on C and also to benchmark the performance of the chip level ADCs against the standard commercial digitizer in terms of noise or resolution. The paper describes implementation of both the methods with performance obtained in both the methods. (author)

Optical Security System Based on the Biometrics Using Holographic Storage Technique with a Simple Data Format

Science.gov (United States)

Jun, An Won

2006-01-01

We implement a first practical holographic security system using electrical biometrics that combines optical encryption and digital holographic memory technologies. Optical information for identification includes a picture of face, a name, and a fingerprint, which has been spatially multiplexed by random phase mask used for a decryption key. For decryption in our biometric security system, a bit-error-detection method that compares the digital bit of live fingerprint with of fingerprint information extracted from hologram is used.

Image recovery from defocused 2D fluorescent images in multimodal digital holographic microscopy.

Science.gov (United States)

Quan, Xiangyu; Matoba, Osamu; Awatsuji, Yasuhiro

2017-05-01

A technique of three-dimensional (3D) intensity retrieval from defocused, two-dimensional (2D) fluorescent images in the multimodal digital holographic microscopy (DHM) is proposed. In the multimodal DHM, 3D phase and 2D fluorescence distributions are obtained simultaneously by an integrated system of an off-axis DHM and a conventional epifluorescence microscopy, respectively. This gives us more information of the target; however, defocused fluorescent images are observed due to the short depth of field. In this Letter, we propose a method to recover the defocused images based on the phase compensation and backpropagation from the defocused plane to the focused plane using the distance information that is obtained from a 3D phase distribution. By applying Zernike polynomial phase correction, we brought back the fluorescence intensity to the focused imaging planes. The experimental demonstration using fluorescent beads is presented, and the expected applications are suggested.

Future of photorefractive based holographic 3D display

Science.gov (United States)

Blanche, P.-A.; Bablumian, A.; Voorakaranam, R.; Christenson, C.; Lemieux, D.; Thomas, J.; Norwood, R. A.; Yamamoto, M.; Peyghambarian, N.

2010-02-01

The very first demonstration of our refreshable holographic display based on photorefractive polymer was published in Nature early 20081. Based on the unique properties of a new organic photorefractive material and the holographic stereography technique, this display addressed a gap between large static holograms printed in permanent media (photopolymers) and small real time holographic systems like the MIT holovideo. Applications range from medical imaging to refreshable maps and advertisement. Here we are presenting several technical solutions for improving the performance parameters of the initial display from an optical point of view. Full color holograms can be generated thanks to angular multiplexing, the recording time can be reduced from minutes to seconds with a pulsed laser, and full parallax hologram can be recorded in a reasonable time thanks to parallel writing. We also discuss the future of such a display and the possibility of video rate.

A new ball-on-disk vacuum tribometer with in situ measurement of the wear track by digital holographic microscopy

Science.gov (United States)

Meylan, B.; Ciani, D.; Zhang, B.; Cuche, E.; Wasmer, K.

2017-12-01

This contribution presents a new ball-on-disk vacuum tribometer with in situ measurement of the wear track by digital holographic microscopy. This new tribometer allows observation of the evolution of the wear track in situ and in real-time. The method combines a high vacuum high temperature ball-on-disk tribometer with a digital holographic microscope (DHM). The machine was tested and validated by taking DHM images during wear tests at room temperature and in vacuum at 2 · 10-6 of polished 100Cr6 steel disks. We demonstrated that the DHM system is well suited to monitor the evolution of the wear track during sliding. We found that, with an acquisition time of 0.1 ms for the DHM, the maximal linear speed is 10 cm s-1 to have reliable images. We proved, via scanning electron microscope (SEM) pictures, that the lines in the sliding direction in all DHM images exist. We also validated the new tribometer by having an excellent correlation between the images and profiles of the wear track taken by the DHM with the ones from a confocal microscope. Finally, the new tribometer combined with the DHM has four advantages. It can test under vacuum and various atmospheric conditions. The evolution of the wear track is measured in situ and in real-time. Hence, the problem of replacing the sample is avoided. Thanks to the DHM technology, the vertical accuracy of the topographical measurement is 4 nm.

Key technology research of nuclear signal digitized pulse shaping in real time

International Nuclear Information System (INIS)

Zhou Jianbin; Wang Min; Zhou Wei; Zhu Xing; Liu Yi; Chen Bao; Lu Baoping; Yue Aizhong; Qin Li; He Xuxin

2014-01-01

The computer simulation and analysis were carried out for the ideal nuclear pulse signal and the actual detector output signals, and the determination method of digital trapezoidal shape parameter for different nuclear pulse shaping time was summarized. At high count rate measurement occasion, the effective count rate is increased, some pile-up pulses are eliminated and the accumulation of dead time of the system is reduced. Meanwhile, Si-PIN semiconductor detector performance was tested by 256 points and 512 points digital triangle forming methods and the analog circuit forming methods for comparative tests. Test results show that the pulse forming treatment method increases the count rate performance and the resolution of detector. (authors)

Holographic memory system based on projection recording of computer-generated 1D Fourier holograms.

Science.gov (United States)

Betin, A Yu; Bobrinev, V I; Donchenko, S S; Odinokov, S B; Evtikhiev, N N; Starikov, R S; Starikov, S N; Zlokazov, E Yu

2014-10-01

Utilization of computer generation of holographic structures significantly simplifies the optical scheme that is used to record the microholograms in a holographic memory record system. Also digital holographic synthesis allows to account the nonlinear errors of the record system to improve the microholograms quality. The multiplexed record of holograms is a widespread technique to increase the data record density. In this article we represent the holographic memory system based on digital synthesis of amplitude one-dimensional (1D) Fourier transform holograms and the multiplexed record of these holograms onto the holographic carrier using optical projection scheme. 1D Fourier transform holograms are very sensitive to orientation of the anamorphic optical element (cylindrical lens) that is required for encoded data object reconstruction. The multiplex record of several holograms with different orientation in an optical projection scheme allowed reconstruction of the data object from each hologram by rotating the cylindrical lens on the corresponding angle. Also, we discuss two optical schemes for the recorded holograms readout: a full-page readout system and line-by-line readout system. We consider the benefits of both systems and present the results of experimental modeling of 1D Fourier holograms nonmultiplex and multiplex record and reconstruction.

Volume holographic memory

Directory of Open Access Journals (Sweden)

Cornelia Denz

2000-05-01

Full Text Available Volume holography represents a promising alternative to existing storage technologies. Its parallel data storage leads to high capacities combined with short access times and high transfer rates. The design and realization of a compact volume holographic storage demonstrator is presented. The technique of phase-coded multiplexing implemented to superimpose many data pages in a single location enables to store up to 480 holograms per storage location without any moving parts. Results of analog and digital data storage are shown and real time optical image processing is demonstrated.

Full characterization of the photorefractive bright soliton formation process using a digital holographic technique

International Nuclear Information System (INIS)

Merola, F; Miccio, L; Paturzo, M; Ferraro, P; De Nicola, S

2009-01-01

An extensive characterization of the photorefractive bright soliton writing process in a lithium niobate crystal is presented. An interferometric approach based on a digital holographic technique has been used to reconstruct the complex wavefield at the exit face of the crystal. Temporal evolution of both intensity and phase profile of the writing beam has been analysed. The effective changes of the refractive index of the medium during the writing process and after the soliton formation are determined from the optical phase distribution. This method provides a reliable way to observe the process of soliton formation, whereas the determination of the intensity distribution of the output beam does not show clearly whether the soliton regime has been achieved or not. Furthermore, a detailed analysis of the soliton in a steady-state situation and under different writing conditions is presented and discussed

Digital holographic microscopy of phase separation in multicomponent lipid membranes

Science.gov (United States)

Farzam Rad, Vahideh; Moradi, Ali-Reza; Darudi, Ahmad; Tayebi, Lobat

2016-12-01

Lateral in-homogeneities in lipid compositions cause microdomains formation and change in the physical properties of biological membranes. With the presence of cholesterol and mixed species of lipids, phospholipid membranes segregate into lateral domains of liquid-ordered and liquid-disordered phases. Coupling of two-dimensional intralayer phase separations and interlayer liquid-crystalline ordering in multicomponent membranes has been previously demonstrated. By the use of digital holographic microscopy (DHMicroscopy), we quantitatively analyzed the volumetric dynamical behavior of such membranes. The specimens are lipid mixtures composed of sphingomyelin, cholesterol, and unsaturated phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine. DHMicroscopy in a transmission mode is an effective tool for quantitative visualization of phase objects. By deriving the associated phase changes, three-dimensional information on the morphology variation of lipid stacks at arbitrary time scales is obtained. Moreover, the thickness distribution of the object at demanded axial planes can be obtained by numerical focusing. Our results show that the volume evolution of lipid domains follows approximately the same universal growth law of previously reported area evolution. However, the thickness of the domains does not alter significantly by time; therefore, the volume evolution is mostly attributed to the changes in area dynamics. These results might be useful in the field of membrane-based functional materials.

Digital Holographic Microscopy, a Method for Detection of Microorganisms in Plume Samples from Enceladus and Other Icy Worlds.

Science.gov (United States)

Bedrossian, Manuel; Lindensmith, Chris; Nadeau, Jay L

2017-09-01

Detection of extant microbial life on Earth and elsewhere in the Solar System requires the ability to identify and enumerate micrometer-scale, essentially featureless cells. On Earth, bacteria are usually enumerated by culture plating or epifluorescence microscopy. Culture plates require long incubation times and can only count culturable strains, and epifluorescence microscopy requires extensive staining and concentration of the sample and instrumentation that is not readily miniaturized for space. Digital holographic microscopy (DHM) represents an alternative technique with no moving parts and higher throughput than traditional microscopy, making it potentially useful in space for detection of extant microorganisms provided that sufficient numbers of cells can be collected. Because sample collection is expected to be the limiting factor for space missions, especially to outer planets, it is important to quantify the limits of detection of any proposed technique for extant life detection. Here we use both laboratory and field samples to measure the limits of detection of an off-axis digital holographic microscope (DHM). A statistical model is used to estimate any instrument's probability of detection at various bacterial concentrations based on the optical performance characteristics of the instrument, as well as estimate the confidence interval of detection. This statistical model agrees well with the limit of detection of 10 3 cells/mL that was found experimentally with laboratory samples. In environmental samples, active cells were immediately evident at concentrations of 10 4 cells/mL. Published estimates of cell densities for Enceladus plumes yield up to 10 4 cells/mL, which are well within the off-axis DHM's limits of detection to confidence intervals greater than or equal to 95%, assuming sufficient sample volumes can be collected. The quantitative phase imaging provided by DHM allowed minerals to be distinguished from cells. Off-axis DHM's ability for

Quantitative measurement of holographic image quality using Adobe Photoshop

International Nuclear Information System (INIS)

Wesly, E

2013-01-01

Measurement of the characteristics of image holograms in regards to diffraction efficiency and signal to noise ratio are demonstrated, using readily available digital cameras and image editing software. Illustrations and case studies, using currently available holographic recording materials, are presented.

Quantitative measurement of holographic image quality using Adobe Photoshop

Science.gov (United States)

Wesly, E.

2013-02-01

Measurement of the characteristics of image holograms in regards to diffraction efficiency and signal to noise ratio are demonstrated, using readily available digital cameras and image editing software. Illustrations and case studies, using currently available holographic recording materials, are presented.

Preliminary results of Digital Pulse Shape Acquisition from Chimera

International Nuclear Information System (INIS)

Alderighi, D.M.; Sechi, G.; Anzalone, A.; Cavallaro, S.; Giustolisi, F.; Laguidara, E.; Lanzalone, G.; Porto, F.; Bassini, R.; Boiano, C.; Guazzoni, P.; Russo, S.; Sassi, M.; Zetta, L.; Cardella, G.; Defilippo, S.E.; Lanzano, G.; Paganod, A.; Papa, M.; Pirrone, S.; Politi, G.; Geraci, E.

2003-01-01

A 100 MS/s 14-bit Sampling Analog-to-Digital converter has been used to perform digital pulse-shape acquisition of signals collected from CHIMERA telescopes. The signals from a typical CHIMERA detection cell have been collected using both a standard CHIMERA electronic chain up to the amplifier, and a very simple analog front end, basically reduced to the preamplifier. The preliminary on-beam results are presented. (authors)

Preliminary results of Digital Pulse Shape Acquisition from Chimera

Energy Technology Data Exchange (ETDEWEB)

Alderighi, D.M.; Sechi, G. [INFN Milano and IASF, CNR, Milano (France); Anzalone, A.; Cavallaro, S.; Giustolisi, F.; Laguidara, E.; Lanzalone, G.; Porto, F. [Catania Univ., LNS and Dipartimento di Fisica (France); Bassini, R.; Boiano, C.; Guazzoni, P.; Russo, S.; Sassi, M.; Zetta, L. [Milano Univ., INFN and Dipartimento di Fisica (Italy); Cardella, G.; Defilippo, S.E.; Lanzano, G.; Paganod, A.; Papa, M.; Pirrone, S.; Politi, G. [Catania Univ., INFN and Dipartimento di Fisica (Italy); Geraci, E. [Bologna Univ., INFN and Dipartimento di Fisica (Italy)

2003-07-01

A 100 MS/s 14-bit Sampling Analog-to-Digital converter has been used to perform digital pulse-shape acquisition of signals collected from CHIMERA telescopes. The signals from a typical CHIMERA detection cell have been collected using both a standard CHIMERA electronic chain up to the amplifier, and a very simple analog front end, basically reduced to the preamplifier. The preliminary on-beam results are presented. (authors)

New techniques in digital holography

CERN Document Server

Picart, Pascal

2015-01-01

A state of the art presentation of important advances in the field of digital holography, detailing advances related to fundamentals of digital holography, in-line holography applied to fluid mechanics, digital color holography, digital holographic microscopy, infrared holography, special techniques in full field vibrometry and inverse problems in digital holography

A new digital pulse generator for the CALIFA detector

Energy Technology Data Exchange (ETDEWEB)

Bendel, Michael; Gernhaeuser, Roman; Heiss, Benjamin; Klenze, Philipp; Remmels, Patrick; Winkel, Max [Physik Department E12, Technische Universitaet Muenchen (Germany); Collaboration: R3B-Collaboration

2015-07-01

The 4π-calorimeter CALIFA ist one of the major detectors of the R3B-experiment at the upcoming Facility for Antiproton and Ion Research in Darmstadt. The monitoring of stability, single channel properties, temperature effects and rate dependency in a high resolution, high granularity calorimeter is essential for the success of the whole experiment. A new digital pulse generator will emulate the complex signal of the CsI(Tl) crystals in order to fine tune the online pulse shape analysis for particle identification, background suppression, energy calibration and for deadtime and pileup studies. The total pulse generator firmware is implemented into the digital readout platform FEBEX used in CALIFA. The FPGA and a small analog add on board allow for highly flexible parameter adjustment. New applications are easy to implement and even very complex shapes are produced by simple lookup tables. The concept, features and implementation of a prototype and a first application in the CALIFA Demonstrator Experiment in October 2014 at GSI in Darmstadt are presented.

Application of digital process controller for automatic pulse operation in the NSRR

International Nuclear Information System (INIS)

Ishijima, K.; Ueda, T.; Saigo, M.

1992-01-01

The NSRR at JAERI is a modified TRIGA Reactor. It was built for investigating reactor fuel behavior under reactivity initiated accident (RIA) conditions. Recently, there has been a need to improve the flexibility of pulsing operations in the NSRR to cover a wide range of accidental situations, including RIA events at elevated power levels, and various abnormal power transients. To satisfy this need, we developed a new reactor control system which allows us to perform 'Shaped Pulse Operation: SP' and 'Combined Pulse Operation: CP'. Quick, accurate and complicated manipulation of control rods was required to realize these operations. Therefore we installed a new reactor control system, which we call an automatic pulse control system. This control system is composed of digital processing controllers and other digital equipments, and is fully automated and highly accurate. (author)

Real-time pulse deinterleaving using digital delay line techniques

Science.gov (United States)

Lentz, L. F.; Palermo, T. J.

This paper describes an implementation of a tracking pulse sorter based on predictive gating techniques. Real-time pulse sorters or pulse train gating devices have been utilized by the ELINT signal analyst for many years. The more elementary of these devices employed a retriggerable delay interval and an acceptance gate, which were used in predictive fashion to track pulse trains whose PRIs fall within the limits of the programmed delay interval. This design utilizes the pulse hit/miss history of individual track files in a variation of a sequential observer detection algorithm. Use of a digital delay line with pulse history allows multiple pulse trains to be tracked simultaneously and independently without interference. The design also provides flexibility in lock-on and track criteria to allow maintenance of acquisition probability and false alarm rate in dense signal environments and with low SNRs. The hardware provides time interval resolution to 12.5 nsec and covers a PRI range of 50 microsec to 50 msec.

A scheme for recording a fast process at nanosecond scale by using digital holographic interferometry with continuous wave laser

Science.gov (United States)

Wang, Jun; Zhao, Jianlin; Di, Jianglei; Jiang, Biqiang

2015-04-01

A scheme for recording fast process at nanosecond scale by using digital holographic interferometry with continuous wave (CW) laser is described and demonstrated experimentally, which employs delayed-time fibers and angular multiplexing technique and can realize the variable temporal resolution at nanosecond scale and different measured depths of object field at certain temporal resolution. The actual delay-time is controlled by two delayed-time fibers with different lengths. The object field information in two different states can be simultaneously recorded in a composite hologram. This scheme is also suitable for recording fast process at picosecond scale, by using an electro-optic modulator.

Ultra-realistic imaging advanced techniques in analogue and digital colour holography

CERN Document Server

Bjelkhagen, Hans

2013-01-01

Ultra-high resolution holograms are now finding commercial and industrial applications in such areas as holographic maps, 3D medical imaging, and consumer devices. Ultra-Realistic Imaging: Advanced Techniques in Analogue and Digital Colour Holography brings together a comprehensive discussion of key methods that enable holography to be used as a technique of ultra-realistic imaging.After a historical review of progress in holography, the book: Discusses CW recording lasers, pulsed holography lasers, and reviews optical designs for many of the principal laser types with emphasis on attaining th

Holographic three-dimensional telepresence using large-area photorefractive polymer.

Science.gov (United States)

Blanche, P-A; Bablumian, A; Voorakaranam, R; Christenson, C; Lin, W; Gu, T; Flores, D; Wang, P; Hsieh, W-Y; Kathaperumal, M; Rachwal, B; Siddiqui, O; Thomas, J; Norwood, R A; Yamamoto, M; Peyghambarian, N

2010-11-04

Holography is a technique that is used to display objects or scenes in three dimensions. Such three-dimensional (3D) images, or holograms, can be seen with the unassisted eye and are very similar to how humans see the actual environment surrounding them. The concept of 3D telepresence, a real-time dynamic hologram depicting a scene occurring in a different location, has attracted considerable public interest since it was depicted in the original Star Wars film in 1977. However, the lack of sufficient computational power to produce realistic computer-generated holograms and the absence of large-area and dynamically updatable holographic recording media have prevented realization of the concept. Here we use a holographic stereographic technique and a photorefractive polymer material as the recording medium to demonstrate a holographic display that can refresh images every two seconds. A 50 Hz nanosecond pulsed laser is used to write the holographic pixels. Multicoloured holographic 3D images are produced by using angular multiplexing, and the full parallax display employs spatial multiplexing. 3D telepresence is demonstrated by taking multiple images from one location and transmitting the information via Ethernet to another location where the hologram is printed with the quasi-real-time dynamic 3D display. Further improvements could bring applications in telemedicine, prototyping, advertising, updatable 3D maps and entertainment.

Parallel database search and prime factorization with magnonic holographic memory devices

Energy Technology Data Exchange (ETDEWEB)

Khitun, Alexander [Electrical and Computer Engineering Department, University of California - Riverside, Riverside, California 92521 (United States)

2015-12-28

In this work, we describe the capabilities of Magnonic Holographic Memory (MHM) for parallel database search and prime factorization. MHM is a type of holographic device, which utilizes spin waves for data transfer and processing. Its operation is based on the correlation between the phases and the amplitudes of the input spin waves and the output inductive voltage. The input of MHM is provided by the phased array of spin wave generating elements allowing the producing of phase patterns of an arbitrary form. The latter makes it possible to code logic states into the phases of propagating waves and exploit wave superposition for parallel data processing. We present the results of numerical modeling illustrating parallel database search and prime factorization. The results of numerical simulations on the database search are in agreement with the available experimental data. The use of classical wave interference may results in a significant speedup over the conventional digital logic circuits in special task data processing (e.g., √n in database search). Potentially, magnonic holographic devices can be implemented as complementary logic units to digital processors. Physical limitations and technological constrains of the spin wave approach are also discussed.

Parallel database search and prime factorization with magnonic holographic memory devices

Science.gov (United States)

Khitun, Alexander

2015-12-01

In this work, we describe the capabilities of Magnonic Holographic Memory (MHM) for parallel database search and prime factorization. MHM is a type of holographic device, which utilizes spin waves for data transfer and processing. Its operation is based on the correlation between the phases and the amplitudes of the input spin waves and the output inductive voltage. The input of MHM is provided by the phased array of spin wave generating elements allowing the producing of phase patterns of an arbitrary form. The latter makes it possible to code logic states into the phases of propagating waves and exploit wave superposition for parallel data processing. We present the results of numerical modeling illustrating parallel database search and prime factorization. The results of numerical simulations on the database search are in agreement with the available experimental data. The use of classical wave interference may results in a significant speedup over the conventional digital logic circuits in special task data processing (e.g., √n in database search). Potentially, magnonic holographic devices can be implemented as complementary logic units to digital processors. Physical limitations and technological constrains of the spin wave approach are also discussed.

Parallel database search and prime factorization with magnonic holographic memory devices

International Nuclear Information System (INIS)

Khitun, Alexander

2015-01-01

In this work, we describe the capabilities of Magnonic Holographic Memory (MHM) for parallel database search and prime factorization. MHM is a type of holographic device, which utilizes spin waves for data transfer and processing. Its operation is based on the correlation between the phases and the amplitudes of the input spin waves and the output inductive voltage. The input of MHM is provided by the phased array of spin wave generating elements allowing the producing of phase patterns of an arbitrary form. The latter makes it possible to code logic states into the phases of propagating waves and exploit wave superposition for parallel data processing. We present the results of numerical modeling illustrating parallel database search and prime factorization. The results of numerical simulations on the database search are in agreement with the available experimental data. The use of classical wave interference may results in a significant speedup over the conventional digital logic circuits in special task data processing (e.g., √n in database search). Potentially, magnonic holographic devices can be implemented as complementary logic units to digital processors. Physical limitations and technological constrains of the spin wave approach are also discussed

High resolution imaging of particle interactions in a large bubble chamber using holographic techniques

International Nuclear Information System (INIS)

Akbari, Homaira.

1988-01-01

Particle interactions were recorded holographically in a large volume of the 15-foot Bubble Chamber at Fermilab. This cryogenic bubble chamber was filled with a heavy Neon-Hydrogen mixture and was exposed to a wideband neutrino beam with mean energy of 150 GeV. The use of holography in combination with conventional photography provides a powerful tool for direct detection of short-lived particles. Holography gives a high resolution over a large depth of field which can not be achieved with conventional photography. A high-power pulsed ruby laser was used as the holographic light source. Since short pulses of some 50 ns duration at the required energy were found to give rise to boiling during the chamber's expansion, a reduction of the instantaneous power at a given energy was required to suppress this unwanted after-effect. This was achieved by developing a unique technique for stretching the pulses using an electro-optic feedback loop. One hundred thousand holograms were produced during a wide-band neutrino experiment (E-632, 1985) using a dark-field holographic system. Analysis of a sample of holograms shows a resolution of 150 μm was achieved in an ovoidal shape fiducial volume of 0.48 m 3 % of the 14 m 3 total fiducial volume of the chamber

Quantitative phase-digital holographic microscopy: a new imaging modality to identify original cellular biomarkers of diseases

KAUST Repository

Marquet, P.

2016-05-03

Quantitative phase microscopy (QPM) has recently emerged as a powerful label-free technique in the field of living cell imaging allowing to non-invasively measure with a nanometric axial sensitivity cell structure and dynamics. Since the phase retardation of a light wave when transmitted through the observed cells, namely the quantitative phase signal (QPS), is sensitive to both cellular thickness and intracellular refractive index related to the cellular content, its accurate analysis allows to derive various cell parameters and monitor specific cell processes, which are very likely to identify new cell biomarkers. Specifically, quantitative phase-digital holographic microscopy (QP-DHM), thanks to its numerical flexibility facilitating parallelization and automation processes, represents an appealing imaging modality to both identify original cellular biomarkers of diseases as well to explore the underlying pathophysiological processes.

Digital discrimination of neutrons and γ-rays in liquid scintillators using pulse gradient analysis

International Nuclear Information System (INIS)

D'Mellow, B.; Aspinall, M.D.; Mackin, R.O.; Joyce, M.J.; Peyton, A.J.

2007-01-01

A method for the digital discrimination of neutrons and γ-rays in mixed radiation fields is described. Pulses in the time domain, arising from the interaction of photons and neutrons in a liquid scintillator, have been produced using an accepted empirical model and from experimental measurements with an americium-beryllium source. Neutrons and γ-rays have been successfully discriminated in both of these data sets in the digital domain. The digital discrimination method described in this paper is simple and exploits samples early in the life of the pulse. It is thus compatible with current embedded system technologies, offers a degree of immunity to pulse pile-up and heralds a real-time means for neutron/γ discrimination that is fundamental to many potential industrial applications

Particle identification using digital pulse shape discrimination in a nTD silicon detector with a 1 GHz sampling digitizer

Science.gov (United States)

Mahata, K.; Shrivastava, A.; Gore, J. A.; Pandit, S. K.; Parkar, V. V.; Ramachandran, K.; Kumar, A.; Gupta, S.; Patale, P.

2018-06-01

In beam test experiments have been carried out for particle identification using digital pulse shape analysis in a 500 μm thick Neutron Transmutation Doped (nTD) silicon detector with an indigenously developed FPGA based 12 bit resolution, 1 GHz sampling digitizer. The nTD Si detector was used in a low-field injection setup to detect light heavy-ions produced in reactions of ∼ 5 MeV/A 7Li and 12C beams on different targets. Pulse height, rise time and current maximum have been obtained from the digitized charge output of a high bandwidth charge and current sensitive pre-amplifier. Good isotopic separation have been achieved using only the digitized charge output in case of light heavy-ions. The setup can be used for charged particle spectroscopy in nuclear reactions involving light heavy-ions around the Coulomb barrier energies.

Label-free sensor for automatic identification of erythrocytes using digital in-line holographic microscopy and machine learning.

Science.gov (United States)

Go, Taesik; Byeon, Hyeokjun; Lee, Sang Joon

2018-04-30

Cell types of erythrocytes should be identified because they are closely related to their functionality and viability. Conventional methods for classifying erythrocytes are time consuming and labor intensive. Therefore, an automatic and accurate erythrocyte classification system is indispensable in healthcare and biomedical fields. In this study, we proposed a new label-free sensor for automatic identification of erythrocyte cell types using a digital in-line holographic microscopy (DIHM) combined with machine learning algorithms. A total of 12 features, including information on intensity distributions, morphological descriptors, and optical focusing characteristics, is quantitatively obtained from numerically reconstructed holographic images. All individual features for discocytes, echinocytes, and spherocytes are statistically different. To improve the performance of cell type identification, we adopted several machine learning algorithms, such as decision tree model, support vector machine, linear discriminant classification, and k-nearest neighbor classification. With the aid of these machine learning algorithms, the extracted features are effectively utilized to distinguish erythrocytes. Among the four tested algorithms, the decision tree model exhibits the best identification performance for the training sets (n = 440, 98.18%) and test sets (n = 190, 97.37%). This proposed methodology, which smartly combined DIHM and machine learning, would be helpful for sensing abnormal erythrocytes and computer-aided diagnosis of hematological diseases in clinic. Copyright © 2017 Elsevier B.V. All rights reserved.

A novel digital pulse processing architecture for nuclear instrumentation

Energy Technology Data Exchange (ETDEWEB)

Moline, Yoann; Thevenin, Mathieu; Corre, Gwenole [CEA, LIST - Laboratoire Capteurs et Architectures electroniques, F-91191 Gif-sur-Yvette, (France); Paindavoine, Michel [CNRS, Universite de Bourgogne - Laboratoire d' Etude de l' Apprentissage et du Developpement, 21000 DIJON, (France)

2015-07-01

The field of nuclear instrumentation covers a wide range of applications, including counting, spectrometry, pulse shape discrimination and multi-channel coincidence. These applications are the topic of many researches, new algorithms and implementations are constantly proposed thanks to advances in digital signal processing. However, these improvements are not yet implemented in instrumentation devices. This is especially true for neutron-gamma discrimination applications which traditionally use charge comparison method while literature proposes other algorithms based on frequency domain or wavelet theory which show better performances. Another example is pileups which are generally rejected while pileup correction algorithms also exist. These processes are traditionally performed offline due to two issues. The first is the Poissonian characteristic of the signal, composed of random arrival pulses which requires to current architectures to work in data flow. The second is the real-time requirement, which implies losing pulses when the pulse rate is too high. Despite the possibility of treating the pulses independently from each other, current architectures paralyze the acquisition of the signal during the processing of a pulse. This loss is called dead-time. These two issues have led current architectures to use dedicated solutions based on re-configurable components like Field Programmable Gate Arrays (FPGAs) to overcome the need of performance necessary to deal with dead-time. However, dedicated hardware algorithm implementations on re-configurable technologies are complex and time-consuming. For all these reasons, a programmable Digital pulse Processing (DPP) architecture in a high level language such as Cor C++ which can reduce dead-time would be worthwhile for nuclear instrumentation. This would reduce prototyping and test duration by reducing the level of hardware expertise to implement new algorithms. However, today's programmable solutions do not meet

A novel digital pulse processing architecture for nuclear instrumentation

International Nuclear Information System (INIS)

Moline, Yoann; Thevenin, Mathieu; Corre, Gwenole; Paindavoine, Michel

2015-01-01

The field of nuclear instrumentation covers a wide range of applications, including counting, spectrometry, pulse shape discrimination and multi-channel coincidence. These applications are the topic of many researches, new algorithms and implementations are constantly proposed thanks to advances in digital signal processing. However, these improvements are not yet implemented in instrumentation devices. This is especially true for neutron-gamma discrimination applications which traditionally use charge comparison method while literature proposes other algorithms based on frequency domain or wavelet theory which show better performances. Another example is pileups which are generally rejected while pileup correction algorithms also exist. These processes are traditionally performed offline due to two issues. The first is the Poissonian characteristic of the signal, composed of random arrival pulses which requires to current architectures to work in data flow. The second is the real-time requirement, which implies losing pulses when the pulse rate is too high. Despite the possibility of treating the pulses independently from each other, current architectures paralyze the acquisition of the signal during the processing of a pulse. This loss is called dead-time. These two issues have led current architectures to use dedicated solutions based on re-configurable components like Field Programmable Gate Arrays (FPGAs) to overcome the need of performance necessary to deal with dead-time. However, dedicated hardware algorithm implementations on re-configurable technologies are complex and time-consuming. For all these reasons, a programmable Digital pulse Processing (DPP) architecture in a high level language such as Cor C++ which can reduce dead-time would be worthwhile for nuclear instrumentation. This would reduce prototyping and test duration by reducing the level of hardware expertise to implement new algorithms. However, today's programmable solutions do not meet

Quantification of mammalian tumor cell state plasticity with digital holographic cytometry

Science.gov (United States)

Hejna, Miroslav; Jorapur, Aparna; Zhang, Yuntian; Song, Jun S.; Judson, Robert L.

2018-02-01

Individual cells within isogenic tumor populations can exhibit distinct cellular morphologies, behaviors, and molecular profiles. Cell state plasticity refers to the propensity of a cell to transition between these different morphologies and behaviors. Elevation of cell state plasticity is thought to contribute to critical stages in tumor evolution, including metastatic dissemination and acquisition of therapeutic resistance. However, methods for quantifying general plasticity in mammalian cells remain limited. Working with a HoloMonitor M4 digital holographic cytometry platform, we have established a machine learning-based pipeline for high accuracy and label-free classification of adherent cells. We use twenty-six morphological and optical density-derived features for label-free identification of cell state in heterogeneous cultures. The system is housed completely within a mammalian cell incubator, permitting the monitoring of changes in cell state over time. Here we present an application of our approach for studying cell state plasticity. Human melanoma cell lines of known metastatic potential were monitored in standard growth conditions. The rate of feature change was quantified for each individual cell in the populations. We observed that cells of higher metastatic potential exhibited more rapid fluctuation of cell state in homeostatic conditions. The approach we demonstrate will be advantageous for further investigations into the factors that influence cell state plasticity.

Quantitative assessment of cancer cell morphology and motility using telecentric digital holographic microscopy and machine learning.

Science.gov (United States)

Lam, Van K; Nguyen, Thanh C; Chung, Byung M; Nehmetallah, George; Raub, Christopher B

2018-03-01

The noninvasive, fast acquisition of quantitative phase maps using digital holographic microscopy (DHM) allows tracking of rapid cellular motility on transparent substrates. On two-dimensional surfaces in vitro, MDA-MB-231 cancer cells assume several morphologies related to the mode of migration and substrate stiffness, relevant to mechanisms of cancer invasiveness in vivo. The quantitative phase information from DHM may accurately classify adhesive cancer cell subpopulations with clinical relevance. To test this, cells from the invasive breast cancer MDA-MB-231 cell line were cultured on glass, tissue-culture treated polystyrene, and collagen hydrogels, and imaged with DHM followed by epifluorescence microscopy after staining F-actin and nuclei. Trends in cell phase parameters were tracked on the different substrates, during cell division, and during matrix adhesion, relating them to F-actin features. Support vector machine learning algorithms were trained and tested using parameters from holographic phase reconstructions and cell geometric features from conventional phase images, and used to distinguish between elongated and rounded cell morphologies. DHM was able to distinguish between elongated and rounded morphologies of MDA-MB-231 cells with 94% accuracy, compared to 83% accuracy using cell geometric features from conventional brightfield microscopy. This finding indicates the potential of DHM to detect and monitor cancer cell morphologies relevant to cell cycle phase status, substrate adhesion, and motility. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

UV laser interaction with a fluorescent dye solution studied using pulsed digital holography.

Science.gov (United States)

Amer, Eynas; Gren, Per; Sjödahl, Mikael

2013-10-21

A frequency tripled Q-switched Nd-YAG laser (wavelength 355 nm, pulse duration 12 ns) has been used to pump Coumarin 153 dye solved in ethanol. Simultaneously, a frequency doubled pulse (532 nm) from the same laser is used to probe the solvent perpendicularly resulting in a gain through stimulated laser induced fluorescence (LIF) emission. The resulting gain of the probe beam is recorded using digital holography by blending it with a reference beam on the detector. Two digital holograms without and with the pump beam were recorded. Intensity maps were calculated from the recorded digital holograms and used to calculate the gain of the probe beam due to the stimulated LIF. In addition numerical data of the local temperature rise was calculated from the corresponding phase maps using Radon inversion. It was concluded that about 15% of the pump beam energy is transferred to the dye solution as heat while the rest is consumed in the radiative process. The results show that pulsed digital holography is a promising technique for quantitative study of fluorescent species.

Single-shot femtosecond-pulsed phase-shifting digital holography.

Science.gov (United States)

Kakue, Takashi; Itoh, Seiya; Xia, Peng; Tahara, Tatsuki; Awatsuji, Yasuhiro; Nishio, Kenzo; Ura, Shogo; Kubota, Toshihiro; Matoba, Osamu

2012-08-27

Parallel phase-shifting digital holography is capable of three-dimensional measurement of a dynamically moving object with a single-shot recording. In this letter, we demonstrated a parallel phase-shifting digital holography using a single femtosecond light pulse whose central wavelength and temporal duration were 800 nm and 96 fs, respectively. As an object, we set spark discharge in atmospheric pressure air induced by applying a high voltage to between two electrodes. The instantaneous change in phase caused by the spark discharge was clearly reconstructed. The reconstructed phase image shows the change of refractive index of air was -3.7 × 10(-4).

An Efficient Digital Pulse Shape Discrimination Technique for Scintillation Detectors Based on FPGA

International Nuclear Information System (INIS)

Kamel, M.S.

2014-01-01

Different techniques for pulse discrimination (PSD) of the scintillation pulses have been developed. The PSD of scintillation pulese can been used in several applications as Positron Emission Topography (PET) system. Each technique analyzes the resulting pulses from the absorption of radiation in the scintillation pulses were filtered and digitized then it is captured using DAQ, and it sent to the host computer for processing. The spatial resolution of images that generated in PET system can be improved by applying the proposed PSD. In this thesis various digital PSD techniques are proposed to discriminate the scintillation pulses. These techniques are based on discrete sine transform (DST). discrete cosine transform (DCT). Discrete hartley transform (DHT), Discrete Goertzel transform (DGT),and principal component analysis (PCA). Then the output coefficients of the discrete transforms are classified using one of the following classifiers T-test,tuned, or support vector machine (SVM).

Investigations on the change of texture of plant cells due to preservative treatments by digital holographic microscopy

Science.gov (United States)

Vora, Priyanka; Anand, Arun

2014-10-01

Texture change is observed in preserved fruits and vegetables. Responsible factors for texture change during preservative treatments are cell morphology, cell wall structure, cell turger, water content and some biochemical components, and also the environmental conditions. Digital Holographic microscopy (DHM) is a quantitative phase contrast imaging technique, which provides three dimensional optical thickness profiles of transparent specimen. Using DHM the morphology of plant cells preserved by refrigeration or stored in vinegar or in sodium chloride can be obtained. This information about the spatio-temporal evolution of optical volume and thickness can be an important tool in area of food processing. Also from the three dimensional images, the texture of the cell can be retrieved and can be investigated under varying conditions.

Short-coherence in-line phase-shifting infrared digital holographic microscopy for measurement of internal structure in silicon

Science.gov (United States)

Xi, Teli; Dou, Jiazhen; Di, Jianglei; Li, Ying; Zhang, Jiwei; Ma, Chaojie; Zhao, Jianlin

2017-06-01

Short-coherence in-line phase-shifting digital holographic microscopy based on Michelson interferometer is proposed to measure internal structure in silicon. In the configuration, a short-coherence infrared laser is used as the light source in order to avoid the interference formed by the reference wave and the reflected wave from the front surface of specimen. At the same time, in-line phase-shifting configuration is introduced to overcome the problem of poor resolution and large pixel size of the infrared camera and improve the space bandwidth product of the system. A specimen with staircase structure is measured by using the proposed configuration and the 3D shape distribution are given to verify the effectiveness and accuracy of the method.

Simultaneous estimation of multiple phases in digital holographic interferometry using state space analysis

Science.gov (United States)

Kulkarni, Rishikesh; Rastogi, Pramod

2018-05-01

A new approach is proposed for the multiple phase estimation from a multicomponent exponential phase signal recorded in multi-beam digital holographic interferometry. It is capable of providing multidimensional measurements in a simultaneous manner from a single recording of the exponential phase signal encoding multiple phases. Each phase within a small window around each pixel is appproximated with a first order polynomial function of spatial coordinates. The problem of accurate estimation of polynomial coefficients, and in turn the unwrapped phases, is formulated as a state space analysis wherein the coefficients and signal amplitudes are set as the elements of a state vector. The state estimation is performed using the extended Kalman filter. An amplitude discrimination criterion is utilized in order to unambiguously estimate the coefficients associated with the individual signal components. The performance of proposed method is stable over a wide range of the ratio of signal amplitudes. The pixelwise phase estimation approach of the proposed method allows it to handle the fringe patterns that may contain invalid regions.

Sensor influence in digital 3λ holographic interferometry

International Nuclear Information System (INIS)

Desse, J M; Picart, P; Tankam, P

2011-01-01

In digital holographic interferometry, the resolution of the reconstructed hologram depends on the pixel size and pixel number of the sensor used for recording. When different wavelengths are simultaneously used as a luminous source for the interferometer, the shape and the overlapping of three filters of a color sensor strongly influence the three reconstructed images. This problem can be directly visualized in 2D Fourier planes on red, green and blue channels. To better understand this problem and to avoid parasitic images generated at the reconstruction, three different sensors have been tested: a CCD sensor equipped with a Bayer filter, a Foveon sensor and a 3CCD sensor. The first one is a Bayer mosaic where one half of the pixels detect the green color and only one-quarter detect the red or blue color. As the missing data are interpolated among color detection positions, offsets and artifacts are generated. The second one is a specific sensor constituted with three stacked photodiode layers. Its technology is different from that of the classical color mosaic sensor because each pixel location detects the three colors simultaneously. So, the three colors are recorded simultaneously with identical spatial resolution, which corresponds to the spatial resolution of the sensor. However, the spectral curve of the sensor is large along each wavelength since the color segmentation is based on the penetration depth of the photons in silicon. Finally, with a 3CCD sensor, each image is recorded on three different sensors with the same resolution. In order to test the sensor influence, we have developed a specific optical bench which allows the near wake flow around a circular cylinder at Mach 0.45 to be characterized. Finally, best results have been obtained with the 3CDD sensor

The use of holographic techniques for recording high-speed events

International Nuclear Information System (INIS)

Stepanov, B.M.; Filenko, Yu.I.

The metods resulting from studies carried out using the commercial holographic device UIG-I are described. The device is intended for recording and investigating moving scenes and high-speed events by a holographic method. It consists of a quantum generator with a two-stage amplifier whose radiation energy in a single-mode operation is 0.7 J, and pulse width for passive Q-switching is 40nsec. Hologram portrait making was one of the experiments which illustrate the possible applications of the device. Hologram portraits such as group portraits and those that can be reconstructed in white light, were obtained on Micrat BP-2 and Agfa Gevaert plates

Study on Digital Pulse Shape Discrimination System in BF{sub 3} Detector

Energy Technology Data Exchange (ETDEWEB)

Kim, Jinhyeong; Kim, J. H.; Choi, H. D. [Seoul National Univ., Seoul (Korea, Republic of)

2013-10-15

In this study, we develop the digital PSD system and discriminate the background signal of BF{sub 3}. Spectrum shapes are different according to the t{sub start} setting method, and it is favorable to set it as the certain ratio of maximum height. In future, it will be performed to vary t{sub start} point to optimize the pulse discrimination. To quantify the performance, Figure Of Merit (FOM) will be determined. For the nuclear non-proliferation and safeguards, an accurate and reliable measurement of nuclear material is essential. The nuclear material emits neutron and γ-ray, simultaneously. For the accurate detection of the nuclear material, neutron should be discriminated from γ-ray or background radiation. In previous study, N. S. Jung developed pulse shape analysis method based on NIM and CAMAC system. However, applications of other discrimination methods based on different detection modules or changing parameters are time-and-money consuming procedures in analogue systems. Today, the performance of digitizers is improved and it replaces some radiation measurement systems which require simple and portable equipment. Digital Pulse Shape Discrimination (PSD) method by using a digital oscilloscope is developed and applied to a neutron detection system by using BF{sub 3} detector in this study.

Problems on holographic imaging technique and adapt lasers for bubble chambers

International Nuclear Information System (INIS)

Bjelkhagen, H.

1982-01-01

Different types of holographic recording technique for bubble chambers are presented and compared. The influence of turbulence on resolution is discussed as well as the demand on laser equipment. Experiments on a test model of HOLEBC using a pulsed ruby laser are also presented. (orig.)

Digital pulse shape discrimination of detector data using fuzzy clustering

International Nuclear Information System (INIS)

Kumar, Abhinav; Chatterjee, A.; Ramachandran, K.; Shrivastava, A.; Mahata, K.

2011-01-01

In accelerator based experiments, data acquisition is done by CAMAC, VME and other systems. The current trend is to digitize the pulse shapes and not just the peak heights of all the input channels, by means of Flash ADCs. In view of the large number of channels involved, this leads to unprecedented data volumes. Therefore, attempts to perform a first level of analysis in real time using algorithms implemented in FPGA have become important. In the present work, digital pulse shape discrimination using fuzzy clustering has been investigated. The attempt has been to devise general purpose PSD Techniques, loosely coupled with the characteristics of detector or particle type, for particle identification. The method is applicable to neutron-gamma discrimination for liquid scintillators and charged particles detected by Si detectors

Holographic non-Gaussianity

International Nuclear Information System (INIS)

McFadden, Paul; Skenderis, Kostas

2011-01-01

We investigate the non-Gaussianity of primordial cosmological perturbations within our recently proposed holographic description of inflationary universes. We derive a holographic formula that determines the bispectrum of cosmological curvature perturbations in terms of correlation functions of a holographically dual three-dimensional non-gravitational quantum field theory (QFT). This allows us to compute the primordial bispectrum for a universe which started in a non-geometric holographic phase, using perturbative QFT calculations. Strikingly, for a class of models specified by a three-dimensional super-renormalisable QFT, the primordial bispectrum is of exactly the factorisable equilateral form with f NL equil. = 5/36, irrespective of the details of the dual QFT. A by-product of this investigation is a holographic formula for the three-point function of the trace of the stress-energy tensor along general holographic RG flows, which should have applications outside the remit of this work

Full-field wrist pulse signal acquisition and analysis by 3D Digital Image Correlation

Science.gov (United States)

Xue, Yuan; Su, Yong; Zhang, Chi; Xu, Xiaohai; Gao, Zeren; Wu, Shangquan; Zhang, Qingchuan; Wu, Xiaoping

2017-11-01

Pulse diagnosis is an essential part in four basic diagnostic methods (inspection, listening, inquiring and palpation) in traditional Chinese medicine, which depends on longtime training and rich experience, so computerized pulse acquisition has been proposed and studied to ensure the objectivity. To imitate the process that doctors using three fingertips with different pressures to feel fluctuations in certain areas containing three acupoints, we established a five dimensional pulse signal acquisition system adopting a non-contacting optical metrology method, 3D digital image correlation, to record the full-field displacements of skin fluctuations under different pressures. The system realizes real-time full-field vibration mode observation with 10 FPS. The maximum sample frequency is 472 Hz for detailed post-processing. After acquisition, the signals are analyzed according to the amplitude, pressure, and pulse wave velocity. The proposed system provides a novel optical approach for digitalizing pulse diagnosis and massive pulse signal data acquisition for various types of patients.

Synchronization method of digital pulse power supply for heavy ions accelerator in Lanzhou

International Nuclear Information System (INIS)

Wang Rongkun; Zhao Jiang; Wu Fengjun; Zhang Huajian; Chen Youxin; Huang Yuzhen; Gao Daqing; Zhou Zhongzu; Yan Huaihai; Yan Hongbin

2013-01-01

The performance of the synchrotron depends on its synchronization. A kind of synchronization method of digital pulse power supply in Heavy Ion Research Facility in Lanzhou-Cooler Storage Ring (HIRFL-CSR) was presented in detail, which is a kind of system on a programmable chip (SOPC) based on optical fiber and optical-custom component. The test of the digital power supply was performed and the current wave forms of pulse mode were given. The results show that all targets can meet the design requirements. (authors)

Synfograms: a new generation of holographic applications

Science.gov (United States)

Meulien Öhlmann, Odile; Öhlmann, Dietmar; Zacharovas, Stanislovas J.

2008-04-01

The new synthetic Four-dimensional printing technique (Syn4D) Synfogram is introducing time (animation) into spatial configuration of the imprinted three-dimensional shapes. While lenticular solutions offer 2 to 9 stereoscopic images Syn4D offers large format, full colors true 3D visualization printing of 300 to 2500 frames imprinted as holographic dots. This past 2 years Syn4D high-resolution displays proved to be extremely efficient for museums presentation, engineering design, automobile prototyping, and advertising virtual presentation as well as, for portrait and fashion applications. The main advantages of syn4D is that it offers a very easy way of using a variety of digital media, like most of 3D Modelling programs, 3D scan system, video sequences, digital photography, tomography as well as the Syn4D camera track system for life recording of spatial scenes changing in time. The use of digital holographic printer in conjunction with Syn4D image acquiring and processing devices separates printing and imaging creation in such a way that makes four-dimensional printing similar to a conventional digital photography processes where imaging and printing are usually separated in space and time. Besides making content easy to prepare, Syn4D has also developed new display and lighting solutions for trade show, museum, POP, merchandising, etc. The introduction of Synfograms is opening new applications for real life and virtual 4D displays. In this paper we will analyse the 3D market, the properties of the Synfograms and specific applications, the problems we encounter, solutions we find, discuss about customers demand and need for new product development.

Phase recovering algorithms for extended objects encoded in digitally recorded holograms

Directory of Open Access Journals (Sweden)

Peng Z.

2010-06-01

Full Text Available The paper presents algorithms to recover the optical phase of digitally encoded holograms. Algorithms are based on the use of a numerical spherical reconstructing wave. Proof of the validity of the concept is performed through an experimental off axis digital holographic set-up. Two-color digital holographic reconstruction is also investigated. Application of the color set-up and algorithms concerns the simultaneous two-dimensional deformation measurement of an object submitted to a mechanical loading.

Pulse energy dependence of refractive index change in lithium niobium silicate glass during femtosecond laser direct writing.

Science.gov (United States)

Cao, Jing; Poumellec, Bertrand; Brisset, François; Lancry, Matthieu

2018-03-19

Femtosecond laser-induced refractive index changes in lithium niobium silicate glass were explored at high repetition rate (300 fs, 500 kHz) by polarized light microscopy, full-wave retardation plate, quantitative birefringence microscopy, and digital holographic microscopy. We found three regimes on energy increase. The first one corresponds to isotropic negative refractive index change (for pulse energy ranging 0.4-0.8 μJ/pulse, 0.6 NA, 5μm/s, 650μm focusing depth in the glass). The second one (0.8-1.2 μJ/pulse) corresponds to birefringence with well-defined slow axis orientation. The third one (above 1.2 μJ/pulse) is related to birefringence direction fluctuation. Interestingly, these regimes are consistent with crystallization ones. In addition, an asymmetric orientational writing effect has been detected on birefringence. These topics extend the possibility of controlling refractive index change in multi-component glasses.

Discrete excitation of mode pulses using a diode-pumped solid-state digital laser

CSIR Research Space (South Africa)

Ngcobo, Sandile

2016-02-01

Full Text Available In this paper, we experimentally demonstrate novel method of generating discrete excitation of on-demand Lagaurre-Gaussian (LG) mode pulses, in a diode pumped solid-state digital laser. The digital laser comprises of an intra-cavity spatial light...

Image improvement and three-dimensional reconstruction using holographic image processing

Science.gov (United States)

Stroke, G. W.; Halioua, M.; Thon, F.; Willasch, D. H.

1977-01-01

Holographic computing principles make possible image improvement and synthesis in many cases of current scientific and engineering interest. Examples are given for the improvement of resolution in electron microscopy and 3-D reconstruction in electron microscopy and X-ray crystallography, following an analysis of optical versus digital computing in such applications.

A digital laser for on-demand laser modes

CSIR Research Space (South Africa)

Ngcobo, S

2013-08-01

Full Text Available -cavity digitally addressed holographic mirror. The phase and amplitude of the holographic mirror may be controlled simply by writing a computer- generated hologram in the form of a grey-scale image to the device, for on-demand laser modes. We show that we can...

Reduction of parasitic interferences in digital holographic microscopy by numerically decreased coherence length

Science.gov (United States)

Kosmeier, S.; Langehanenberg, P.; von Bally, G.; Kemper, B.

2012-01-01

Due to the large coherence length of laser light, optical path length (OPL) resolution in laser based digital holographic microscopy suffers from parasitic interferences caused by multiple reflections within the experimental setup. Use of partially coherent light reduces this drawback but requires precise and stable matching of object and reference arm's OPLs and limits the spatial frequency of the interference pattern in off-axis holography. Here, we investigate if the noise properties of spectrally broadened light sources can be generated numerically. Therefore, holograms are coherently captured at different laser wavelengths and the corresponding reconstructed wave fields are numerically superimposed utilizing variable weightings. Gaussian and rectangular spectral shapes of the so synthesized field are analyzed with respect to the resulting noise level, which is quantified in OPL distributions of a reflective test target. Utilizing a Gaussian weighting, the noise level is found to be similar to the one obtained with the partially coherent light of a superluminescent diode. With a rectangular shaped synthesized spectrum, noise is reduced more efficient than with a Gaussian one. The applicability of the method in label-free cell analysis is demonstrated by quantitative phase contrast images obtained from living cancer cells.

Digital synthesis of pulse shapes in real time for high resolution radiation spectroscopy

International Nuclear Information System (INIS)

Jordanov, Valentin T.; Knoll, Glenn F.

1994-01-01

Techniques have been developed for the synthesis of pulse shapes using fast digital schemes in place of the traditional analog methods of pulse shaping. Efficient recursive algorithms have been developed that allow real time implementation of a shaper that can produce either trapezoidal or triangular pulse shapes. Other recursive techniques are presented which allow a synthesis of finite cusp-like shapes. Preliminary experimental tests show potential advantages of using these techniques in high resolution, high count rate pulse spectroscopy. ((orig.))

Generator of pulses with the nanosecond duration and accurate amplitude using the digital control in the CAMAC standard

International Nuclear Information System (INIS)

Basiladze, S.G.; Nguen Kuang Min'

1980-01-01

A generator of square-wave fine-amplitude nanosecond pulses is described. The generator is primarily intended for checking the performances of fast electronics analog-to-digital units with the help of a computer. In addition to digital control the pulse amplitude can be controlled manually or by the external voltage. Basic circuits of main generator assemblies: a triggering circuit, transistor key and digital-to-analog converter are given. Output pulses produced by the generator have the following parameters: the amplitude from - 0.15 to - 10 V (smooth or gradual, with a minimum step of 5 mV), the rising and decay pulse times approximately 2 ns, the maximum repetition frequency 10 kHz, the control linearity at a pulse duration of more than 50 ns 0.15%. A double-width CAMAC cell accomodates two generators

Effect of second harmonic in pulse-width-modulation-based DAC for feedback of digital fluxgate magnetometer

Science.gov (United States)

Belyayev, Serhiy; Ivchenko, Nickolay

2018-04-01

Digital fluxgate magnetometers employ processing of the measured pickup signal to produce the value of the compensation current. Using pulse-width modulation with filtering for digital to analog conversion is a convenient approach, but it can introduce an intrinsic source of nonlinearity, which we discuss in this design note. A code shift of one least significant bit changes the second harmonic content of the pulse train, which feeds into the pick-up signal chain despite the heavy filtering. This effect produces a code-dependent nonlinearity. This nonlinearity can be overcome by the specific design of the timing of the pulse train signal. The second harmonic is suppressed if the first and third quarters of the excitation period pulse train are repeated in the second and fourth quarters. We demonstrate this principle on a digital magnetometer, achieving a magnetometer noise level corresponding to that of the sensor itself.

A new digital pulse power supply in heavy ion research facility in Lanzhou

Science.gov (United States)

Wang, Rongkun; Chen, Youxin; Huang, Yuzhen; Gao, Daqing; Zhou, Zhongzu; Yan, Huaihai; Zhao, Jiang; Shi, Chunfeng; Wu, Fengjun; Yan, Hongbin; Xia, Jiawen; Yuan, Youjin

2013-11-01

To meet the increasing requirements of the Heavy Ion Research Facility in Lanzhou-Cooler Storage Ring (HIRFL-CSR), a new digital pulse power supply, which employs multi-level converter, was designed. This power supply was applied with a multi H-bridge converters series-parallel connection topology. A new control model named digital power supply regulator system (DPSRS) was proposed, and a pulse power supply prototype based on DPSRS has been built and tested. The experimental results indicate that tracking error and ripple current meet the requirements of this design. The achievement of prototype provides a perfect model for HIRFL-CSR power supply system.

Comparative analysis of the modified enclosed energy metric for self-focusing holograms from digital lensless holographic microscopy.

Science.gov (United States)

Trujillo, Carlos; Garcia-Sucerquia, Jorge

2015-06-01

A comparative analysis of the performance of the modified enclosed energy (MEE) method for self-focusing holograms recorded with digital lensless holographic microscopy is presented. Notwithstanding the MEE analysis previously published, no extended analysis of its performance has been reported. We have tested the MEE in terms of the minimum axial distance allowed between the set of reconstructed holograms to search for the focal plane and the elapsed time to obtain the focused image. These parameters have been compared with those for some of the already reported methods in the literature. The MEE achieves better results in terms of self-focusing quality but at a higher computational cost. Despite its longer processing time, the method remains within a time frame to be technologically attractive. Modeled and experimental holograms have been utilized in this work to perform the comparative study.

Interference and protection of electromagnetic pulse to digital signal processor

International Nuclear Information System (INIS)

Wang Yan; Jiao Hongling; He Shanhong; Pan Chao; Feng Deren; Che Wenquan; Xiong Ying

2013-01-01

The effective electromagnetic pulse protection is studied in this paper, first the interference of electromagnetic pulse simulator path is analyzed, including the digital signal processor (DSP) and the discharge circuit of coupling interference and net electricity coupling interference. Using the structure optimization design, the hardware block reinforcement measurement and the setting of open software trap, and the watchdog anti-jamming measures, the interference test is completed such as the central processor core voltage of DSP, input/output (I/O) ports of DSP and the display screen. The experimental results show that the combination of hardware and software protection reinforcement technology is effective, and the interference pulse amplitude of DSP board I/O port and the kernel work voltage are reduced, and the interference duration is reduced from 2 μs to 400 ns. The interference pulse is effectively restrained. (authors)

Evaluation of real-time digital pulse shapers with various HPGe and silicon radiation detectors

International Nuclear Information System (INIS)

Menaa, N.; D'Agostino, P.; Zakrzewski, B.; Jordanov, V.T.

2011-01-01

Real-time digital pulse shaping techniques allow synthesis of pulse shapes that have been difficult to realize using the traditional analog methods. Using real-time digital shapers, triangular/trapezoidal filters can be synthesized in real time. These filters exhibit digital control on the rise time, fall time, and flat-top of the trapezoidal shape. Thus, the trapezoidal shape can be adjusted for optimum performance at different distributions of the series and parallel noise. The trapezoidal weighting function (WF) represents the optimum time-limited pulse shape when only parallel and series noises are present in the detector system. In the presence of 1/F noise, the optimum WF changes depending on the 1/F noise contribution. In this paper, we report on the results of the evaluation of new filter types for processing signals from CANBERRA high purity germanium (HPGe) and passivated, implanted, planar silicon (PIPS) detectors. The objective of the evaluation is to determine improvements in performance over the current trapezoidal (digital) filter. The evaluation is performed using a customized CANBERRA digital signal processing unit that is fitted with new FPGA designs and any required firmware modifications to support operation of the new filters. The evaluated filters include the Cusp, one-over-F (1/F), and pseudo-Gaussian filters. The results are compared with the CANBERRA trapezoidal shaper.

Pulse Holography: Review Of Applications

Science.gov (United States)

Smigielski, Paul

1990-04-01

Pulse Holography includes studies concerning time-varying phase objects as well as time-varying reflective objects involving the use of pulse ruby- and YAG-lasers. The paper is divided in two parts. One part concerns the direct use of 3-1) images reconstructed from holograms, i.e. applications to particle size analysis, 3-I) velocity measurements, 3-I) cinematography ... The second part describes applications using holographic interferometry in laboratory or in an industrial environment, i.e. applications to fluid mechanics, vibration analysis, non-destructive testing ... Recent developments including interferornetric cineholography, fiber optics, measurement of non-interferometric displacements ... , are also described. The future of holography depends to a great extent on data processing and interpretation of informations contained in holograms or holographic intericrograms. Therefore, we give the state of art in this field in Europe illustrated with some industrial applications.

Improvements on digital inline holographic PTV for 3D wall-bounded turbulent flow measurements

International Nuclear Information System (INIS)

Toloui, Mostafa; Mallery, Kevin; Hong, Jiarong

2017-01-01

Three-dimensional (3D) particle image velocimetry (PIV) and particle tracking velocimetry (PTV) provide the most comprehensive flow information for unraveling the physical phenomena in a wide range of fluid problems, from microfluidics to wall-bounded turbulent flows. Compared with other 3D PIV techniques, such as tomographic PIV and defocusing PIV, the digital inline holographic PTV (DIH-PTV) provides 3D flow measurement solution with high spatial resolution, low cost optical setup, and easy alignment and calibration. Despite these advantages, DIH-PTV suffers from major limitations including poor longitudinal resolution, human intervention (i.e. requirement for manually determined tuning parameters during tracer field reconstruction and extraction), limited tracer concentration, small sampling volume and expensive computations, limiting its broad use for 3D flow measurements. In this study, we present our latest developments on minimizing these challenges, which enables high-fidelity DIH-PTV implementation to larger sampling volumes with significantly higher particle seeding densities suitable for wall-bounded turbulent flow measurements. The improvements include: (1) adjustable window thresholding; (2) multi-pass 3D tracking; (3) automatic wall localization; and (4) continuity-based out-of-plane velocity component computation. The accuracy of the proposed DIH-PTV method is validated with conventional 2D PIV and double-view holographic PTV measurements in smooth-wall turbulent channel flow experiments. The capability of the technique in characterization of wall-bounded turbulence is further demonstrated through its application to flow measurements for smooth- and rough-wall turbulent channel flows. In these experiments, 3D velocity fields are measured within sampling volumes of 14.7  ×  50.0  ×  14.4 mm 3 (covering the entire depth of the channel) with a velocity resolution of  <1.1 mm/vector. Overall, the presented DIH-PTV method and

Measuring the nanomechanical properties of cancer cells by digital pulsed force mode imaging

International Nuclear Information System (INIS)

Marti, Othmar; Holzwarth, Michael; Beil, Michael

2008-01-01

In this paper, we demonstrate that the digital pulsed force mode data can distinguish two cancer cell lines (HeLa, Panc) by their mechanical properties. The live cells were imaged in buffer solution. The digital pulsed force mode measured 175 force-distance curves per second which, due to the speed of the measurement, were distorted by the viscous drag in the buffer. We show that this drag force causes a sinusoidal addition to the force-distance curves. By subtracting the viscous drag effect one obtains standard force-distance curves. The force-distance curves are then evaluated to extract key data on the curves, such as adhesion energies, local stiffness or the width of the hysteresis loop. These data are then correlated to classify the force-distance curves. We show examples based on the width of the hysteresis loop and the adhesion energies. Outliers in this classification scheme are points where, potentially, interesting new physics or different physics might happen. Based on classification schemes adapted to experimental settings, we propose that the digital pulsed force mode is a tool to evaluate the time evolution of the mechanical response of cells

Measuring the nanomechanical properties of cancer cells by digital pulsed force mode imaging

Energy Technology Data Exchange (ETDEWEB)

Marti, Othmar; Holzwarth, Michael [Institute of Experimental Physics, Ulm University, D-89069 Ulm (Germany); Beil, Michael [Department of Internal Medicine, Ulm University, D-89069 Ulm (Germany)], E-mail: othmar.marti@uni-ulm.de, E-mail: michael.holzwarth@uni-ulm.de, E-mail: michael.beil@uni-ulm.de

2008-09-24

In this paper, we demonstrate that the digital pulsed force mode data can distinguish two cancer cell lines (HeLa, Panc) by their mechanical properties. The live cells were imaged in buffer solution. The digital pulsed force mode measured 175 force-distance curves per second which, due to the speed of the measurement, were distorted by the viscous drag in the buffer. We show that this drag force causes a sinusoidal addition to the force-distance curves. By subtracting the viscous drag effect one obtains standard force-distance curves. The force-distance curves are then evaluated to extract key data on the curves, such as adhesion energies, local stiffness or the width of the hysteresis loop. These data are then correlated to classify the force-distance curves. We show examples based on the width of the hysteresis loop and the adhesion energies. Outliers in this classification scheme are points where, potentially, interesting new physics or different physics might happen. Based on classification schemes adapted to experimental settings, we propose that the digital pulsed force mode is a tool to evaluate the time evolution of the mechanical response of cells.

Polychromatic holographic plasma diagnostics

International Nuclear Information System (INIS)

Zhiglinskij, A.G.; Morozov, A.O.

1992-01-01

Review of holographic interferometry properties is performed and advantages of this method by plasma diagnostics are indicated. Main results obtained by the method of holographic interferometry in studies of various-type plasmas are considered. Special attention is paid to multiwave plasma diagnostics, the necessity of which is related as a rule to multicomponent composition of plasma. The eight laser and gas-discharge sources and holographic schemes, which make it possible to realize plasma polychromatic and holographic interferometry, are considered. The advantages of the method are demonstrated by examples of polychromatic holographic diagnostics of arc discharge and discharge in a hollow cathode. Review of theoretical works determining the applicability area of resonance polychromatic interferometry is carried out

Three-dimensional flow measurement of a water flow in a sphere-packed pipe by digital holographic PTV

Energy Technology Data Exchange (ETDEWEB)

Satake, Shin-ichi, E-mail: satake@te.noda.tus.ac.jp [Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585 (Japan); Aoyagi, Yusuke [Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585 (Japan); Unno, Noriyuki [Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585 (Japan); Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Yuki, Kazuhisa [Department of Mechanical Engineering, Tokyo University of Science, Yamaguchi, Daigaku-dori 1-1-1, Sanyo-Onoda, Yamaguchi 756-0884 (Japan); Seki, Yohji; Enoeda, Mikio [Japan Atomic Energy Agency, Blanket Technology Group, 801-1 Mukoyama, Naka-shi, Ibaraki-ken 311-0193 (Japan)

2015-10-15

A water cooled ceramic breeder for ITER and DEMO of a nuclear fusion reactor plays a significant role in the design of a blanket module. Pebbles of a ceramic tritium breeder are packed in a container of the blanket. Investigation of the flow behavior is necessary in an actual environment of a facility where pressure drop takes place under a complex flow such as in case of the container for the pebble bed. For the development of a facility, it is necessary to be able to monitor fluid motion of a basic flow such as a sphere-packed pipe (SPP). In the present study, to discern the complex flow structures in SPP, digital holographic PTV visualization is carried out by a refractive index-matching method using a water employed as a working fluid. The water is chosen to be able to adjust its refractive index to match to that of the MEXFLON pebble with an index of 1.33. Hologram fringe images of particles behind the spheres can be observed, and the particles’ positions can be reconstructed by a digital hologram. Consequently, 3-D velocity-fields around the spheres are obtained by the reconstructed particles’ positions. The velocity between pebbles is found to be convergence and divergence regions in the SPP.

Simple and fast spectral domain algorithm for quantitative phase imaging of living cells with digital holographic microscopy

Science.gov (United States)

Min, Junwei; Yao, Baoli; Ketelhut, Steffi; Kemper, Björn

2017-02-01

The modular combination of optical microscopes with digital holographic microscopy (DHM) has been proven to be a powerful tool for quantitative live cell imaging. The introduction of condenser and different microscope objectives (MO) simplifies the usage of the technique and makes it easier to measure different kinds of specimens with different magnifications. However, the high flexibility of illumination and imaging also causes variable phase aberrations that need to be eliminated for high resolution quantitative phase imaging. The existent phase aberrations compensation methods either require add additional elements into the reference arm or need specimen free reference areas or separate reference holograms to build up suitable digital phase masks. These inherent requirements make them unpractical for usage with highly variable illumination and imaging systems and prevent on-line monitoring of living cells. In this paper, we present a simple numerical method for phase aberration compensation based on the analysis of holograms in spatial frequency domain with capabilities for on-line quantitative phase imaging. From a single shot off-axis hologram, the whole phase aberration can be eliminated automatically without numerical fitting or pre-knowledge of the setup. The capabilities and robustness for quantitative phase imaging of living cancer cells are demonstrated.

Holographic wavefront characterization of a frequency-tripled high-peak-power neodymium:glass laser

International Nuclear Information System (INIS)

Kessler, T.J.

1984-01-01

Near-field amplitude and phase distributions from a high-peak-power, frequency converted Nd:glass laser (lambda = 351 nm) have been holographically recorded on silver-halide emulsions. Conventionally, the absence of a suitable reference beam forces one to use some type of shearing interferometry to obtain phasefront information, while the near-field and far-field distributions are recorded as intensity profiles. In this study, a spatially filtered, locally generated reference beam was created to holographically store the complex amplitude distribution of the pulsed laser beam, while reconstruction of the original wavefront was achieved with a continuous-wave laser. Reconstructed near-field and quasi-far-field intensity distributions closely resembled those obtained from conventional techniques, and accurate phasefront reconstruction was achieved. Furthermore, several two-beam interferometric techniques, not practicable with a high-peak-power laser, have been successfully implemented on a continuous-wave reconstruction of the pulsed laser beam. 46 refs., 40 figs., 1 tab

Holographic memories

DEFF Research Database (Denmark)

Ramanujam, P.S.; Berg, R.H.; Hvilsted, Søren

1999-01-01

A Two-dimensional holographic memory for archival storage is described. Assuming a coherent transfer function, an A4 page can be stored at high resolution in an area of 1 mm(2). Recently developed side-chain liquid crystalline azobenzene polyesters are found to be suitable media for holographic...

A New Approach for Speckle Reduction in Holographic 3D printer

International Nuclear Information System (INIS)

Utsugi, Takeru; Yamaguchi, Masahiro

2013-01-01

A Holographic 3D printer produces a high quality 3D image reproduced by a full-color, full-parallax holographic stereogram with high-density light-ray recording. But speckle-pattern noise localized behind the reconstructed image is causing a loss of the display quality. This noise is originated from the speckle generated by a diffuser for equalizing the intensity distribution of the object light on the recording medium. We analyze some conventional ways for speckle reduction using a band-limited diffuser, and it is found that these ways cannot reduce the noise sufficiently. Then we propose two methods, one introduces a moving diffuser and the other introduces multiple exposures and a digital diffuser called as 4L-PRPS.

Measurement of spatial refractive index distributions of fusion spliced optical fibers by digital holographic microtomography

Science.gov (United States)

Pan, Feng; Deng, Yating; Ma, Xichao; Xiao, Wen

2017-11-01

Digital holographic microtomography is improved and applied to the measurements of three-dimensional refractive index distributions of fusion spliced optical fibers. Tomographic images are reconstructed from full-angle phase projection images obtained with a setup-rotation approach, in which the laser source, the optical system and the image sensor are arranged on an optical breadboard and synchronously rotated around the fixed object. For retrieving high-quality tomographic images, a numerical method is proposed to compensate the unwanted movements of the object in the lateral, axial and vertical directions during rotation. The compensation is implemented on the two-dimensional phase images instead of the sinogram. The experimental results exhibit distinctly the internal structures of fusion splices between a single-mode fiber and other fibers, including a multi-mode fiber, a panda polarization maintaining fiber, a bow-tie polarization maintaining fiber and a photonic crystal fiber. In particular, the internal structure distortion in the fusion areas can be intuitively observed, such as the expansion of the stress zones of polarization maintaining fibers, the collapse of the air holes of photonic crystal fibers, etc.

Holographic dark energy models: a comparison from the latest observational data

International Nuclear Information System (INIS)

Li, Miao; Li, Xiao-Dong; Wang, Shuang; Zhang, Xin

2009-01-01

The holographic principle of quantum gravity theory has been applied to the dark energy (DE) problem, and so far three holographic DE models have been proposed: the original holographic dark energy (HDE) model, the agegraphic dark energy (ADE) model, and the holographic Ricci dark energy (RDE) model. In this work, we perform the best-fit analysis on these three models, by using the latest observational data including the Union+CFA3 sample of 397 Type Ia supernovae (SNIa), the shift parameter of the cosmic microwave background (CMB) given by the five-year Wilkinson Microwave Anisotropy Probe (WMAP5) observations, and the baryon acoustic oscillation (BAO) measurement from the Sloan Digital Sky Survey (SDSS). The analysis shows that for HDE, χ min 2 = 465.912; for RDE, χ min 2 = 483.130; for ADE, χ min 2 = 481.694. Among these models, HDE model can give the smallest χ 2 min . Besides, we also use the Bayesian evidence (BE) as a model selection criterion to make a comparison. It is found that for HDE, ADE, and RDE, Δln BE = −0.86, −5.17, and −8.14, respectively. So, it seems that the HDE model is more favored by the observational data

Neutron-Gamma Pulse Shape Discrimination With Ne-213 Liquid Scintillator By Using Digital Signal Processing Combined With Similarity Method

International Nuclear Information System (INIS)

Mardiyanto

2008-01-01

Neutron-Gamma Pulse Shape Discrimination with a NE-213 Liquid Scintillator by Using Digital Signal Processing Combined with Similarity Method. Measurement of mixed neutron-gamma radiation is difficult because a nuclear detector is usually sensitive to both radiations. A new attempt of neutron-gamma pulse shape discrimination for a NE-213 liquid scintillator is presented by using digital signal processing combined with an off-line similarity method. The output pulse shapes are digitized with a high speed digital oscilloscope. The n-γ discrimination is done by calculating the index of each pulse shape, which is determined by the similarity method, and then fusing it with its corresponding pulse height. Preliminary results demonstrate good separation of neutron and gamma-ray signals from a NE-213 scintillator with a simple digital system. The results were better than those with a conventional rise time method. Figure of Merit is used to determine the quality of discrimination. The figure of merit of the discrimination using digital signal processing combined with off-line similarity method are 1.9; 1.7; 1.1; 1.1; and 0.8; on the other hand by using conventional method the rise time are 0.9; 0.9; 0.9; 0.7; and 0.4 for the equivalent electron energy of 800; 278; 139; 69; and 30 keV. (author)

Measurement of Piezoelectric Transformer Vibrations by Digital Holography

Czech Academy of Sciences Publication Activity Database

Psota, Pavel; Lédl, Vít; Doleček, Roman; Erhart, J.; Kopecký, V.

2014-01-01

Roč. 59, č. 9 (2014), s. 1962-1968 ISSN 0885-3010 R&D Projects: GA MŠk(CZ) ED2.1.00/03.0079 Institutional support: RVO:61389021 Keywords : digital holographic * ime-averaged holographic * small amplitude * vibrations amplitude measurement * piezoelectric transformer s Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.512, year: 2014

Automatic phase aberration compensation for digital holographic microscopy based on deep learning background detection.

Science.gov (United States)

Nguyen, Thanh; Bui, Vy; Lam, Van; Raub, Christopher B; Chang, Lin-Ching; Nehmetallah, George

2017-06-26

We propose a fully automatic technique to obtain aberration free quantitative phase imaging in digital holographic microscopy (DHM) based on deep learning. The traditional DHM solves the phase aberration compensation problem by manually detecting the background for quantitative measurement. This would be a drawback in real time implementation and for dynamic processes such as cell migration phenomena. A recent automatic aberration compensation approach using principle component analysis (PCA) in DHM avoids human intervention regardless of the cells' motion. However, it corrects spherical/elliptical aberration only and disregards the higher order aberrations. Traditional image segmentation techniques can be employed to spatially detect cell locations. Ideally, automatic image segmentation techniques make real time measurement possible. However, existing automatic unsupervised segmentation techniques have poor performance when applied to DHM phase images because of aberrations and speckle noise. In this paper, we propose a novel method that combines a supervised deep learning technique with convolutional neural network (CNN) and Zernike polynomial fitting (ZPF). The deep learning CNN is implemented to perform automatic background region detection that allows for ZPF to compute the self-conjugated phase to compensate for most aberrations.

Off-axis low coherence digital holographic interferometry for quantitative phase imaging with an LED

Science.gov (United States)

Guo, Rongli; Wang, Fan; Hu, Xiaoying; Yang, Wenqian

2017-11-01

Off-axis digital holographic interferometry with the light source of a light emitting diode (LED) is presented and its application for quantitative phase imaging in a large range with low noise is demonstrated. The scheme is implemented in a grating based Mach-Zehnder interferometer. To achieve off-axis interferometry, firstly, the collimated beam emitted from an LED is diffracted into multiple orders by a grating and they are split into two copies by a beam splitter; secondly, in the object arm the zero order of one copy is filtered in the Fourier plane and is reshaped to illuminate the sample, while in the reference arm one of its first order of another copy is selected to serve as the reference beam, and then an off-axis hologram can be obtained at the image plane. The main advantage stemming from an LED illumination is its high spatial phase resolution, due to the subdued speckle effect. The off-axis geometry enables one-shot recording of the hologram in the millisecond scale. The utility of the proposed setup is illustrated with measurements of a resolution target and part of a wing of green-lacewing, and dynamic evaporation process of an ethanol film.

A study of the real-time deconvolution of digitized waveforms with pulse pile up for digital radiation spectroscopy

International Nuclear Information System (INIS)

Guo Weijun; Gardner, Robin P.; Mayo, Charles W.

2005-01-01

Two new real-time approaches have been developed and compared to the least-squares fit approach for the deconvolution of experimental waveforms with pile-up pulses. The single pulse shape chosen is typical for scintillators such as LSO and NaI(Tl). Simulated waveforms with pulse pile up were also generated and deconvolved to compare these three different approaches under cases where the single pulse component has a constant shape and the digitization error dominates. The effects of temporal separation and amplitude ratio between pile-up component pulses were also investigated and statistical tests were applied to quantify the consistency of deconvolution results for each case. Monte Carlo simulation demonstrated that applications of these pile-up deconvolution techniques to radiation spectroscopy are effective in extending the counting-rate range while preserving energy resolution for scintillation detectors

A high speed digital signal averager for pulsed NMR

International Nuclear Information System (INIS)

Srinivasan, R.; Ramakrishna, J.; Ra agopalan, S.R.

1978-01-01

A 256-channel digital signal averager suitable for pulsed nuclear magnetic resonance spectroscopy is described. It implements 'stable averaging' algorithm and hence provides a calibrated display of the average signal at all times during the averaging process on a CRT. It has a maximum sampling rate of 2.5 μ sec and a memory capacity of 256 x 12 bit words. Number of sweeps is selectable through a front panel control in binary steps from 2 3 to 2 12 . The enhanced signal can be displayed either on a CRT or by a 3.5-digit LED display. The maximum S/N improvement that can be achieved with this instrument is 36 dB. (auth.)

Tests on a digital neutron-gamma pulse shape discriminator with NE213

International Nuclear Information System (INIS)

Bell, Z.W.

1981-01-01

A technique using charge sensitive analog-to-digital converters to do neutron-gamma pulse shape discrimination is reported. The converters are gated by short (135 ns) pulses so as to reduce pile-up and the timing is such that the slow and total light output from the scintillator are measured. Preliminary tests indicate that the system performs reasonably well but poorer than some reported analog systems employing gated integrators or cross-over techniques. (orig.)

Nonvolatile Rad-Hard Holographic Memory

Science.gov (United States)

Chao, Tien-Hsin; Zhou, Han-Ying; Reyes, George; Dragoi, Danut; Hanna, Jay

2001-01-01

We are investigating a nonvolatile radiation-hardened (rad-hard) holographic memory technology. Recently, a compact holographic data storage (CHDS) breadboard utilizing an innovative electro-optic scanner has been built and demonstrated for high-speed holographic data storage and retrieval. The successful integration of this holographic memory breadboard has paved the way for follow-on radiation resistance test of the photorefractive (PR) crystal, Fe:LiNbO3. We have also started the investigation of using two-photon PR crystals that are doubly doped with atoms of iron group (Ti, Cr, Mn, Cu) and of rare-earth group (Nd, Tb) for nonvolatile holographic recordings.

Digital pulse-timing technique for the neutron detector array NEDA

Energy Technology Data Exchange (ETDEWEB)

Modamio, V., E-mail: victor.modamio@lnl.infn.it [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Valiente-Dobón, J.J. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Jaworski, G. [Faculty of Physics, Warsaw University of Technology, 00-662 Warszawa (Poland); Heavy Ion Laboratory, University of Warsaw, 02-093 Warszawa (Poland); Hüyük, T. [Instituto de Física Corpuscular, CSIC-Universitat de València, E-46980 Valencia (Spain); Triossi, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Egea, J. [Instituto de Física Corpuscular, CSIC-Universitat de València, E-46980 Valencia (Spain); Department of Electronic Engineering, Universitat de València, E-46100 Burjassot (Spain); Di Nitto, A. [Johannes Gutenberg-Universität Mainz, D-55099 Mainz (Germany); Söderström, P.-A. [RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, 351-0198 Saitama (Japan); Agramunt Ros, J. [Instituto de Física Corpuscular, CSIC-Universitat de València, E-46980 Valencia (Spain); Angelis, G. de [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); France, G. de [GANIL, CEA/DSAM and CNRS/IN2P3, F-14076 Caen (France); Erduran, M.N. [Faculty of Engineering and Natural Sciences, Istanbul Sabahattin Zaim University, 34303 Istanbul (Turkey); and others

2015-03-01

A new digital pulse-timing algorithm, to be used with the future neutron detector array NEDA, has been developed and tested. The time resolution of four 5 in. diameter photomultiplier tubes (XP4512, R4144, R11833-100, and ET9390-kb), coupled to a cylindrical 5 in. by 5 in. BC501A liquid scintillator detector was measured by employing digital sampling electronics and a constant fraction discriminator (CFD) algorithm. The zero crossing of the CFD algorithm was obtained with a cubic spline interpolation, which was continuous up to the second derivative. The performance of the algorithm was studied at sampling rates of 500 MS/s and 200 MS/s. The time resolution obtained with the digital electronics was compared to the values acquired with a standard analog CFD. The result of this comparison shows that the time resolution from the analog and the digital measurements at 500 MS/s and at 200 MS/s are within 15% for all the tested photomultiplier tubes.

Optical studies in the holographic ground station

Science.gov (United States)

Workman, Gary L.

1991-01-01

The Holographic Group System (HGS) Facility in rooms 22 & 123, Building 4708 has been developed to provide for ground based research in determining pre-flight parameters and analyzing the results from space experiments. The University of Alabama, Huntsville (UAH) has researched the analysis aspects of the HGS and reports their findings here. Some of the results presented here also occur in the Facility Operating Procedure (FOP), which contains instructions for power up, operation, and powerdown of the Fluid Experiment System (FES) Holographic Ground System (HGS) Test Facility for the purpose of optically recording fluid and/or crystal behavior in a test article during ground based testing through the construction of holograms and recording of videotape. The alignment of the optical bench components, holographic reconstruction and and microscopy alignment sections were also included in the document for continuity even though they are not used until after optical recording of the test article) setup of support subsystems and the Automated Holography System (AHS) computer. The HGS provides optical recording and monitoring during GCEL runs or development testing of potential FES flight hardware or software. This recording/monitoring can be via 70mm holographic film, standard videotape, or digitized images on computer disk. All optical bench functions necessary to construct holograms will be under the control of the AHS personal computer (PC). These include type of exposure, time intervals between exposures, exposure length, film frame identification, film advancement, film platen evacuation and repressurization, light source diffuser introduction, and control of realtime video monitoring. The completed sequence of hologram types (single exposure, diffuse double exposure, etc.) and their time of occurrence can be displayed, printed, or stored on floppy disk posttest for the user.

A holographic bound for D3-brane

Energy Technology Data Exchange (ETDEWEB)

Momeni, Davood; Myrzakul, Aizhan; Myrzakulov, Ratbay [Eurasian National University, Eurasian International Center for Theoretical Physics, Astana (Kazakhstan); Eurasian National University, Department of General Theoretical Physics, Astana (Kazakhstan); Faizal, Mir [University of British Columbia-Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Bahamonde, Sebastian [University College London, Department of Mathematics, London (United Kingdom)

2017-06-15

In this paper, we will regularize the holographic entanglement entropy, holographic complexity and fidelity susceptibility for a configuration of D3-branes. We will also study the regularization of the holographic complexity from the action for a configuration of D3-branes. It will be demonstrated that for a spherical shell of D3-branes the regularized holographic complexity is always greater than or equal to the regularized fidelity susceptibility. Furthermore, we will also demonstrate that the regularized holographic complexity is related to the regularized holographic entanglement entropy for this system. Thus, we will obtain a holographic bound involving regularized holographic complexity, regularized holographic entanglement entropy and regularized fidelity susceptibility of a configuration of D3-brane. We will also discuss a bound for regularized holographic complexity from action, for a D3-brane configuration. (orig.)

Digital control of laser modes with an intra-cavity spatial light modulator

CSIR Research Space (South Africa)

Ngcobo, S

2014-02-01

Full Text Available addressed holographic end-mirror. We show that on-demand digitally controlled laser modes are possible by changing the phase and amplitude of the computer generated hologram in a form of a grey-scale image on the holographic mirror. We demonstrate...

REAL TIME MICRODISPLACEMENTS TESTING BY OPTO-DIGITAL HOLOGRAPHIC INTERFEROMETRY TECHNIQUE

Directory of Open Access Journals (Sweden)

L BOUAMAMA

2007-12-01

Since all the process is controlled numerically, it is possible to follow in real time using the holographic interferometry techniques, double exposure, real time or time average, any changes in the object under study and to start and stop the process at any time by adequate software. This can be done by subtracting a reference image by suitable software directly on the CCD camera. We show also, the ability of the technique to study in real time all evolutional phenomena.

50 mm Diameter digital DC/pulse neutron generator for subcritical reactor test

International Nuclear Information System (INIS)

Li Gang; Zhang Zhongshuai; Chi Qian; Liu Linmao

2012-01-01

A 50 mm diameter digital DC/pulse neutron generator was developed with 25 mm ceramic drive-in target neutron tube. It was applied in the subcritical reactor test of China Institute of Atomic Energy (CIAE). The generator can produce neutron in three modes: DC, pulse and multiple pulse. The maximum neutron yield of the generator is 1 × 10 8 n/s, while the maximum pulse frequency is 10 kHz, and the minimum pulse width is 10 μs. As a remote controlled generator, it is small in volume, easy to be connected and controlled. The tested results indicate that penning ion source has the feature of delay time in glow discharge, and it is easier for glow discharge to happen when switching the DC voltage of penning ion source into pulse. According to these two characteristics, the generator has been modified. This improved generator can be used in many other areas including Prompt Gamma Neutron Activation Analysis (PGNAA), neutron testing and experiment.

50 mm Diameter digital DC/pulse neutron generator for subcritical reactor test

Energy Technology Data Exchange (ETDEWEB)

Li Gang; Zhang Zhongshuai [Northeast Normal University, Changchun 130024 (China); Chi Qian [Guang Hua College of Chang Chun University, Changchun 130117 (China); Liu Linmao, E-mail: ll888@nenu.edu.cn [Northeast Normal University, Changchun 130024 (China)

2012-11-01

A 50 mm diameter digital DC/pulse neutron generator was developed with 25 mm ceramic drive-in target neutron tube. It was applied in the subcritical reactor test of China Institute of Atomic Energy (CIAE). The generator can produce neutron in three modes: DC, pulse and multiple pulse. The maximum neutron yield of the generator is 1 Multiplication-Sign 10{sup 8} n/s, while the maximum pulse frequency is 10 kHz, and the minimum pulse width is 10 {mu}s. As a remote controlled generator, it is small in volume, easy to be connected and controlled. The tested results indicate that penning ion source has the feature of delay time in glow discharge, and it is easier for glow discharge to happen when switching the DC voltage of penning ion source into pulse. According to these two characteristics, the generator has been modified. This improved generator can be used in many other areas including Prompt Gamma Neutron Activation Analysis (PGNAA), neutron testing and experiment.

Digital holographic microscopy as a technique to monitor macrophages infected by leishmania

Science.gov (United States)

Mendoza-Rodríguez, E.; Organista-Castelblanco, C.; Camacho, M.; Monroy-Ramírez, F.

2017-06-01

The Digital Holographic Microscopy in Transmission technique (DHM) is considered a useful tool in the noninvasive quantifying of transparent biological objects like living cells. In this work, we propose this technique to study and to monitor control macrophages infected by Leishmania (mouse lineJ774.A1). When the promastigotes enter in contact with healthy macrophages, they got phagocytosed and latterly confined in the formed parasitophorous vacuole. These processes change the morphology and density of the host macrophage. Both parameters can be measured in a label-free analysis of cells with the aid of the DHM technique. Our technique begins with the optical record of the holograms using a modified Mach-Zehnder interferometer and the reconstruction of the complex optical field transmitted by macrophages. In the latter point, we employ the angular spectrum algorithm. With the complex optical field reconstruction, we compute the field amplitude and the phase difference maps, which leads to describe one morphological characterization for the samples. Using phase difference maps is possible to measure internal variations for the integral refractive index, estimating the infection level of macrophages. Through the changes in the integral refractive index, it is also possible to describe and quantify in two different states the evolution of the infection. With these results some parameters of cells have been quantified, making the DHM technique a viable tool for diagnosis of biological samples under the presence of some pathogen.

A wireless reflectance pulse oximeter with digital baseline control for unfiltered photoplethysmograms.

Science.gov (United States)

Li, Kejia; Warren, Steve

2012-06-01

Pulse oximeters are central to the move toward wearable health monitoring devices and medical electronics either hosted by, e.g., smart phones or physically embedded in their design. This paper presents a small, low-cost pulse oximeter design appropriate for wearable and surface-based applications that also produces quality, unfiltered photo-plethysmograms (PPGs) ideal for emerging diagnostic algorithms. The design's "filter-free" embodiment, which employs only digital baseline subtraction as a signal compensation mechanism, distinguishes it from conventional pulse oximeters that incorporate filters for signal extraction and noise reduction. This results in high-fidelity PPGs with thousands of peak-to-peak digitization levels that are sampled at 240 Hz to avoid noise aliasing. Electronic feedback controls make these PPGs more resilient in the face of environmental changes (e.g., the device can operate in full room light), and data stream in real time across either a ZigBee wireless link or a wired USB connection to a host. On-board flash memory is available for store-and-forward applications. This sensor has demonstrated an ability to gather high-integrity data at fingertip, wrist, earlobe, palm, and temple locations from a group of 48 subjects (20 to 64 years old).

Digital liquid-scintillation counting and effective pulse-shape discrimination with artificial neural networks

International Nuclear Information System (INIS)

Langrock, Gert; Wiehl, Norbert; Kling, Hans-Otto; Mendel, Matthias; Naehler, Andrea; Tharun, Udo; Eberhardt, Klaus; Trautmann, Norbert; Kratz, Jens Volker

2015-01-01

A typical problem in low-level liquid scintillation (LS) counting is the identification of α particles in the presence of a high background of β and γ particles. Especially the occurrence of β-β and β-γ pile-ups may prevent the unambiguous identification of an α signal by commonly used analog electronics. In this case, pulse-shape discrimination (PSD) and pile-up rejection (PUR) units show an insufficient performance. This problem was also observed in own earlier experiments on the chemical behaviour of transactinide elements using the liquid-liquid extraction system SISAK in combination with LS counting. α-particle signals from the decay of the transactinides could not be unambiguously assigned. However, the availability of instruments for the digital recording of LS pulses changes the situation and provides possibilities for new approaches in the treatment of LS pulse shapes. In a SISAK experiment performed at PSI, Villigen, a fast transient recorder, a PC card with oscilloscope characteristics and a sampling rate of 1 giga samples s -1 (1 ns per point), was used for the first time to record LS signals. It turned out, that the recorded signals were predominantly α β-β and β-γ pile up, and fission events. This paper describes the subsequent development and use of artificial neural networks (ANN) based on the method of 'back-propagation of errors' to automatically distinguish between different pulse shapes. Such networks can 'learn' pulse shapes and classify hitherto unknown pulses correctly after a learning period. The results show that ANN in combination with fast digital recording of pulse shapes can be a powerful tool in LS spectrometry even at high background count rates.

Quantitative investigation of red blood cell three-dimensional geometric and chemical changes in the storage lesion using digital holographic microscopy.

Science.gov (United States)

Jaferzadeh, Keyvan; Moon, Inkyu

2015-11-01

Quantitative phase information obtained by digital holographic microscopy (DHM) can provide new insight into the functions and morphology of single red blood cells (RBCs). Since the functionality of a RBC is related to its three-dimensional (3-D) shape, quantitative 3-D geometric changes induced by storage time can help hematologists realize its optimal functionality period. We quantitatively investigate RBC 3-D geometric changes in the storage lesion using DHM. Our experimental results show that the substantial geometric transformation of the biconcave-shaped RBCs to the spherocyte occurs due to RBC storage lesion. This transformation leads to progressive loss of cell surface area, surface-to-volume ratio, and functionality of RBCs. Furthermore, our quantitative analysis shows that there are significant correlations between chemical and morphological properties of RBCs.

HOLIMO II: a digital holographic instrument for ground-based in situ observations of microphysical properties of mixed-phase clouds

Science.gov (United States)

Henneberger, J.; Fugal, J. P.; Stetzer, O.; Lohmann, U.

2013-11-01

Measurements of the microphysical properties of mixed-phase clouds with high spatial resolution are important to understand the processes inside these clouds. This work describes the design and characterization of the newly developed ground-based field instrument HOLIMO II (HOLographic Imager for Microscopic Objects II). HOLIMO II uses digital in-line holography to in situ image cloud particles in a well-defined sample volume. By an automated algorithm, two-dimensional images of single cloud particles between 6 and 250 μm in diameter are obtained and the size spectrum, the concentration and water content of clouds are calculated. By testing the sizing algorithm with monosized beads a systematic overestimation near the resolution limit was found, which has been used to correct the measurements. Field measurements from the high altitude research station Jungfraujoch, Switzerland, are presented. The measured number size distributions are in good agreement with parallel measurements by a fog monitor (FM-100, DMT, Boulder USA). The field data shows that HOLIMO II is capable of measuring the number size distribution with a high spatial resolution and determines ice crystal shape, thus providing a method of quantifying variations in microphysical properties. A case study over a period of 8 h has been analyzed, exploring the transition from a liquid to a mixed-phase cloud, which is the longest observation of a cloud with a holographic device. During the measurement period, the cloud does not completely glaciate, contradicting earlier assumptions of the dominance of the Wegener-Bergeron-Findeisen (WBF) process.

HOLIMO II: a digital holographic instrument for ground-based in-situ observations of microphysical properties of mixed-phase clouds

Science.gov (United States)

Henneberger, J.; Fugal, J. P.; Stetzer, O.; Lohmann, U.

2013-05-01

Measurements of the microphysical properties of mixed-phase clouds with high spatial resolution are important to understand the processes inside these clouds. This work describes the design and characterization of the newly developed ground-based field instrument HOLIMO II (HOLographic Imager for Microscopic Objects II). HOLIMO II uses digital in-line holography to in-situ image cloud particles in a well defined sample volume. By an automated algorithm, two-dimensional images of single cloud particles between 6 and 250 μm in diameter are obtained and the size spectrum, the concentration and water content of clouds are calculated. By testing the sizing algorithm with monosized beads a systematic overestimation near the resolution limit was found, which has been used to correct the measurements. Field measurements from the high altitude research station Jungfraujoch, Switzerland, are presented. The measured number size distributions are in good agreement with parallel measurements by a fog monitor (FM-100, DMT, Boulder USA). The field data shows that HOLIMO II is capable of measuring the number size distribution with a high spatial resolution and determines ice crystal shape, thus providing a method of quantifying variations in microphysical properties. A case study over a period of 8 h has been analyzed, exploring the transition from a liquid to a mixed-phase cloud, which is the longest observation of a cloud with a holographic device. During the measurement period, the cloud does not completely glaciate, contradicting earlier assumptions of the dominance of the Wegener-Bergeron-Findeisen (WBF) process.

Design and calibration of a digital Fourier holographic microscope for particle sizing via goniometry and optical scatter imaging in transmission.

Science.gov (United States)

Rossi, Vincent M; Jacques, Steven L

2016-06-13

Goniometry and optical scatter imaging have been used for optical determination of particle size based upon optical scattering. Polystyrene microspheres in suspension serve as a standard for system validation purposes. The design and calibration of a digital Fourier holographic microscope (DFHM) are reported. Of crucial importance is the appropriate scaling of scattering angle space in the conjugate Fourier plane. A detailed description of this calibration process is described. Spatial filtering of the acquired digital hologram to use photons scattered within a restricted angular range produces an image. A pair of images, one using photons narrowly scattered within 8 - 15° (LNA), and one using photons broadly scattered within 8 - 39° (HNA), are produced. An image based on the ratio of these two images, OSIR = HNA/LNA, following Boustany et al. (2002), yields a 2D Optical Scatter Image (OSI) whose contrast is based on the angular dependence of photon scattering and is sensitive to the microsphere size, especially in the 0.5-1.0µm range. Goniometric results are also given for polystyrene microspheres in suspension as additional proof of principle for particle sizing via the DFHM.

Random noise effects in pulse-mode digital multilayer neural networks.

Science.gov (United States)

Kim, Y C; Shanblatt, M A

1995-01-01

A pulse-mode digital multilayer neural network (DMNN) based on stochastic computing techniques is implemented with simple logic gates as basic computing elements. The pulse-mode signal representation and the use of simple logic gates for neural operations lead to a massively parallel yet compact and flexible network architecture, well suited for VLSI implementation. Algebraic neural operations are replaced by stochastic processes using pseudorandom pulse sequences. The distributions of the results from the stochastic processes are approximated using the hypergeometric distribution. Synaptic weights and neuron states are represented as probabilities and estimated as average pulse occurrence rates in corresponding pulse sequences. A statistical model of the noise (error) is developed to estimate the relative accuracy associated with stochastic computing in terms of mean and variance. Computational differences are then explained by comparison to deterministic neural computations. DMNN feedforward architectures are modeled in VHDL using character recognition problems as testbeds. Computational accuracy is analyzed, and the results of the statistical model are compared with the actual simulation results. Experiments show that the calculations performed in the DMNN are more accurate than those anticipated when Bernoulli sequences are assumed, as is common in the literature. Furthermore, the statistical model successfully predicts the accuracy of the operations performed in the DMNN.

Investigation of dynamic of unconsolidated materials using two-color digital holography

Directory of Open Access Journals (Sweden)

Boileau J.-P.

2010-06-01

Full Text Available The paper presents a two-color digital holographic interferometer. The set-up is devoted to the study of the fundamental dynamic of unconsolidated materials. Optical configuration and algorithms to recover the optical phase of two-color digitally encoded holograms are described. The method is based on a spatial-color-multiplexing scheme in which holographic reconstruction is performed using adapted wavelength zero-padding and reconstructing distance. Experimental results are presented in the case of granular media excited in the frequency range 400Hz-3000Hz and exhibits the 3D movement.

The Technology and Properties of Digital Double Pulse Electrodepositing Ni-HA Composite Coating of Bioceramics

Institute of Scientific and Technical Information of China (English)

DONG He-yan; WANG Zhou; SHI Gu-guizhi; FU Chuan-qi; CHEN Wei-rong; JIN Zhong-hong; LI Yan

2004-01-01

This article discusses and analyses the technology, the surface image, microstructure and ability of digital double pulse electrodepositing Ni-HA composite coatings of bioceramics made on 1Crl8Ni9Ti substrate by SEM ,XRD and so on. The results shows that ( 1 ) the HA particles exit in substrate uniformly; (2) XRD result shows that there are HA peaks at 78. 023 ° ,43. 246°and 73. 120°differently; (3) The microhardnees of the composite coatings is increased with the rise of content of HA particles, and on the same conditions the microhardnees value is greater than that of common non-pulse electrodepositing Ni-HA composite coatings of bioceramics. (4) The grain size of digital double pulse electrodepositing Ni-HA composite coatings of bioceramics is much thinner than that of common D. C.

Comparison of the analog and digital pulse-shaping methods in signal processing in nuclear detections

International Nuclear Information System (INIS)

Golnabi, H.

2002-01-01

The goal of this article is to describe the potential applications of the new improved digital techniques and provide a meaningful figure of merit for the comparison of the analog and digital methods. The experimental operation of a typical digital pulse shaper used in a spectrometer with the 23 Na source and a Ge y-ray detector is discussed. The effect of different imposed dead time on the counted pulses is investigated. It is noticed that nuclear events distribution in all ranges of dead time does not obey Poisson's law and deviation from this distribution depends on the counting rate. For a given dead time, deviation from this distribution increases linearly by increasing imposed dead time. For a fixed dead time, when counting rate increases deviation from Poisson's distribution law increases accordingly, and vice versa. (Author)

Digital liquid-scintillation counting and effective pulse-shape discrimination with artificial neural networks

Energy Technology Data Exchange (ETDEWEB)

Langrock, Gert; Wiehl, Norbert; Kling, Hans-Otto; Mendel, Matthias; Naehler, Andrea; Tharun, Udo; Eberhardt, Klaus; Trautmann, Norbert; Kratz, Jens Volker [Mainz Univ. (Germany). Inst. fuer Kernchemie; Omtvedt, Jon-Petter [Oslo Univ. (Norway). Dept. of Chemistry; Skarnemark, Gunnar [Chalmers Univ. of Technology, Goeteborg (Sweden)

2015-05-01

A typical problem in low-level liquid scintillation (LS) counting is the identification of α particles in the presence of a high background of β and γ particles. Especially the occurrence of β-β and β-γ pile-ups may prevent the unambiguous identification of an α signal by commonly used analog electronics. In this case, pulse-shape discrimination (PSD) and pile-up rejection (PUR) units show an insufficient performance. This problem was also observed in own earlier experiments on the chemical behaviour of transactinide elements using the liquid-liquid extraction system SISAK in combination with LS counting. α-particle signals from the decay of the transactinides could not be unambiguously assigned. However, the availability of instruments for the digital recording of LS pulses changes the situation and provides possibilities for new approaches in the treatment of LS pulse shapes. In a SISAK experiment performed at PSI, Villigen, a fast transient recorder, a PC card with oscilloscope characteristics and a sampling rate of 1 giga samples s{sup -1} (1 ns per point), was used for the first time to record LS signals. It turned out, that the recorded signals were predominantly α β-β and β-γ pile up, and fission events. This paper describes the subsequent development and use of artificial neural networks (ANN) based on the method of 'back-propagation of errors' to automatically distinguish between different pulse shapes. Such networks can 'learn' pulse shapes and classify hitherto unknown pulses correctly after a learning period. The results show that ANN in combination with fast digital recording of pulse shapes can be a powerful tool in LS spectrometry even at high background count rates.

Some characteristics of the digitization pulses from high pressure neon-helium flash tubes

International Nuclear Information System (INIS)

Chan, D.S.K.; Leung, S.K.; Ng, L.K.

1979-01-01

Characteristics of the digitization output pulses from high pressure neon-helium flash tubes were studied under various operation conditions using square ultra-high voltage pulses. Properties reported by previous workers were compared. Two discharge mechanisms, the Townsend avalanche discharge and the streamer discharge, were observed to occur in sequence in some events. The output waveforms for both discharge mechanisms were studied in detail. The charge induced on a detecting probe was also estimated from the measured data. (Auth.)

COMPARISON OF HOLOGRAPHIC AND ITERATIVE METHODS FOR AMPLITUDE OBJECT RECONSTRUCTION

Directory of Open Access Journals (Sweden)

I. A. Shevkunov

2015-01-01

Full Text Available Experimental comparison of four methods for the wavefront reconstruction is presented. We considered two iterative and two holographic methods with different mathematical models and algorithms for recovery. The first two of these methods do not use a reference wave recording scheme that reduces requirements for stability of the installation. A major role in phase information reconstruction by such methods is played by a set of spatial intensity distributions, which are recorded as the recording matrix is being moved along the optical axis. The obtained data are used consistently for wavefront reconstruction using an iterative procedure. In the course of this procedure numerical distribution of the wavefront between the planes is performed. Thus, phase information of the wavefront is stored in every plane and calculated amplitude distributions are replaced for the measured ones in these planes. In the first of the compared methods, a two-dimensional Fresnel transform and iterative calculation in the object plane are used as a mathematical model. In the second approach, an angular spectrum method is used for numerical wavefront propagation, and the iterative calculation is carried out only between closely located planes of data registration. Two digital holography methods, based on the usage of the reference wave in the recording scheme and differing from each other by numerical reconstruction algorithm of digital holograms, are compared with the first two methods. The comparison proved that the iterative method based on 2D Fresnel transform gives results comparable with the result of common holographic method with the Fourier-filtering. It is shown that holographic method for reconstructing of the object complex amplitude in the process of the object amplitude reduction is the best among considered ones.

Investigation of crack initiation with a three color digital holographic interferometer

Science.gov (United States)

Karray, Mayssa; Poilane, Christophe; Mounier, Denis; Gargoury, Mohamed; Picart, Pascal

2012-10-01

This paper proposes a three-color holographic interferometer devoted to the deformation analysis of a composite material submitted to a short beam shear test. The simultaneous recording of three laser wavelengths using a triple CCD sensor results in the evaluation of shear strains at the lateral surface of the sample. Such an evaluation provides a pertinent parameter to detect premature crack in the structure, long before it becomes visible on the real time stress/strain curve, or with a classical microscope.

Sparsity-based multi-height phase recovery in holographic microscopy

KAUST Repository

Rivenson, Yair

2016-11-30

High-resolution imaging of densely connected samples such as pathology slides using digital in-line holographic microscopy requires the acquisition of several holograms, e.g., at >6–8 different sample-to-sensor distances, to achieve robust phase recovery and coherent imaging of specimen. Reducing the number of these holographic measurements would normally result in reconstruction artifacts and loss of image quality, which would be detrimental especially for biomedical and diagnostics-related applications. Inspired by the fact that most natural images are sparse in some domain, here we introduce a sparsity-based phase reconstruction technique implemented in wavelet domain to achieve at least 2-fold reduction in the number of holographic measurements for coherent imaging of densely connected samples with minimal impact on the reconstructed image quality, quantified using a structural similarity index. We demonstrated the success of this approach by imaging Papanicolaou smears and breast cancer tissue slides over a large field-of-view of ~20 mm2 using 2 in-line holograms that are acquired at different sample-to-sensor distances and processed using sparsity-based multi-height phase recovery. This new phase recovery approach that makes use of sparsity can also be extended to other coherent imaging schemes, involving e.g., multiple illumination angles or wavelengths to increase the throughput and speed of coherent imaging.

Sparsity-based multi-height phase recovery in holographic microscopy

Science.gov (United States)

Rivenson, Yair; Wu, Yichen; Wang, Hongda; Zhang, Yibo; Feizi, Alborz; Ozcan, Aydogan

2016-11-01

High-resolution imaging of densely connected samples such as pathology slides using digital in-line holographic microscopy requires the acquisition of several holograms, e.g., at >6-8 different sample-to-sensor distances, to achieve robust phase recovery and coherent imaging of specimen. Reducing the number of these holographic measurements would normally result in reconstruction artifacts and loss of image quality, which would be detrimental especially for biomedical and diagnostics-related applications. Inspired by the fact that most natural images are sparse in some domain, here we introduce a sparsity-based phase reconstruction technique implemented in wavelet domain to achieve at least 2-fold reduction in the number of holographic measurements for coherent imaging of densely connected samples with minimal impact on the reconstructed image quality, quantified using a structural similarity index. We demonstrated the success of this approach by imaging Papanicolaou smears and breast cancer tissue slides over a large field-of-view of ~20 mm2 using 2 in-line holograms that are acquired at different sample-to-sensor distances and processed using sparsity-based multi-height phase recovery. This new phase recovery approach that makes use of sparsity can also be extended to other coherent imaging schemes, involving e.g., multiple illumination angles or wavelengths to increase the throughput and speed of coherent imaging.

Investigation of crack origin in hybrid components with twocolor digital Fresnel holography

Directory of Open Access Journals (Sweden)

Moisson E.

2010-06-01

Full Text Available The paper presents a two-color digital holographic interferometer. The set-up is devoted to the investigation of crack origin in hybrid industrial electronic components. Optical configuration and algorithms to recover the optical phase of two-color digitally encoded holograms are described. The method is based on a spatial-color-multiplexing scheme in which holographic reconstruction is performed using a spectral scanning algorithm. Experimental results exhibit in-plane and out-of-plane non uniform deformations that are the probable cause of the cracking of the component.

Holography and holographic dark energy model

International Nuclear Information System (INIS)

Gong Yungui; Zhang Yuanzhong

2005-01-01

The holographic principle is used to discuss the holographic dark energy model. We find that the Bekenstein-Hawking entropy bound is far from saturation under certain conditions. A more general constraint on the parameter of the holographic dark energy model is also derived

Investigation on cytoskeleton dynamics for no-adherent cells subjected to point-like stimuli by digital holographic microscopy and holographic optical trapping

Science.gov (United States)

Miccio, Lisa; Merola, Francesco; Memmolo, Pasquale; Mugnano, Martina; Fusco, Sabato; Netti, Paolo A.; Ferraro, Pietro

2014-05-01

Guiding, controlling and studying cellular functions are challenging themes in the biomedical field, as they are fundamental prerequisites for new therapeutic strategies from tissue regeneration to controlled drug delivery. In recent years, multidisciplinary studies in nanotechnology offer new tools to investigate important biophysical phenomena in response to the local physical characteristics of the extracellular environment, some examples are the mechanisms of cell adhesion, migration, communication and differentiation. Indeed for reproducing the features of the extracellular matrix in vitro, it is essential to develop active devices that evoke as much as possible the natural cellular environment. Our investigation is in the framework of studying and clarifying the biophysical mechanisms of the interaction between cells and the microenvironment in which they exist. We implement an optical tweezers setup to investigate cell material interaction and we use Digital Holography as non-invasive imaging technique in microscopy. We exploit Holographic Optical Tweezers arrangement in order to trap and manage functionalized micrometric latex beads to induce mechanical deformation in suspended cells. A lot of papers in literature examine the dynamics of the cytoskeleton when cells adhere on substrates and nowadays well established cell models are based on such research activities. Actually, the natural cell environment is made of a complex extracellular matrix and the single cell behavior is due to intricate interactions with the environment and are strongly correlated to the cell-cell interactions. Our investigation is devoted to understand the inner cell mechanism when it is mechanically stressed by point-like stimulus without the substrate influence.

Influence of sampling properties of fast-waveform digitizers on neutron−gamma-ray, pulse-shape discrimination for organic scintillation detectors

International Nuclear Information System (INIS)

Flaska, Marek; Faisal, Muhammad; Wentzloff, David D.; Pozzi, Sara A.

2013-01-01

One of the most important questions to be answered with regard to digital pulse-shape discrimination (PSD) systems based on organic scintillators is: What sampling properties are required for a fast-waveform digitizer used for digitizing neutron/gamma-ray pulses, while an accurate PSD is desired? Answering this question is the main objective of this paper. Specifically, the paper describes the influence of the resolution and sampling frequency of a waveform digitizer on the PSD performance of organic scintillators. The results presented in this paper are meant to help the reader choosing a waveform digitizer with appropriate bit resolution and sampling frequency. The results presented here show that a 12-bit, 250-MHz digitizer is a good choice for applications that require good PSD performance. However, when more accurate PSD performance is the main requirement, this paper presents PSD figures of merit to qualify the impact of further increasing either sampling frequency or resolution of the digitizer

A non-iterative twin image elimination method with two in-line digital holograms

Science.gov (United States)

Kim, Jongwu; Lee, Heejung; Jeon, Philjun; Kim, Dug Young

2018-02-01

We propose a simple non-iterative in-line holographic measurement method which can effectively eliminate a twin image in digital holographic 3D imaging. It is shown that a twin image can be effectively eliminated with only two measured holograms by using a simple numerical propagation algorithm and arithmetic calculations.

Holographic Moire Contouring

Science.gov (United States)

Sciammarella, C. A.; Sainov, Ventseslav; Simova, Eli

1990-04-01

Theoretical analysis and experimental results on holographic moire contouring (HMC) of difussely reflecting objects are presented. The sensitivity and application constraints of the method are discussed. A high signal-to-noise ratio and contrast of the fringes is achieved through the use of high quality silver halide holographic plates HP-650. A good agreement between theoretical and experimental results is observed.

Digital holographic interferometry: A novel optical calorimetry technique for radiation dosimetry

Energy Technology Data Exchange (ETDEWEB)

Cavan, Alicia, E-mail: alicia.cavan@cdhb.health.nz [Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand and Christchurch Hospital, Private Bag 4710, Christchurch 8140 (New Zealand); Meyer, Juergen, E-mail: juergen@uw.edu [Department of Radiation Oncology, University of Washington, 1959 Northeast Pacific Street, Box 356043, Seattle, Washington 98195 (United States)

2014-02-15

Purpose: To develop and demonstrate the proof-of-principle of a novel optical calorimetry method to determine radiation absorbed dose in a transparent medium. Methods: The calorimetric property of water is measured during irradiation by means of an interferometer, which detects temperature-induced changes in the refractive index that can be mathematically related to absorbed dose. The proposed method uses a technique called digital holographic interferometry (DHI), which comprises an optical laser interferometer setup and consecutive physical reconstruction of the recorded wave fronts by means of the Fresnel transform. This paper describes the conceptual framework and provides the mathematical basis for DHI dosimetry. Dose distributions from a high dose rate Brachytherapy source were measured by a prototype optical setup to demonstrate the feasibility of the approach. Results: The developed DHI dosimeter successfully determined absorbed dose distributions in water in the region adjacent to a high dose rate Brachytherapy source. A temperature change of 0.0381 K across a distance of 6.8 mm near the source was measured, corresponding to a dose of 159.3 Gy. The standard deviation in a typical measurement set was ±3.45 Gy (corresponding to an uncertainty in the temperature value of ±8.3 × 10{sup −4} K). The relative dose fall off was in agreement with treatment planning system modeled data. Conclusions: First results with a prototype optical setup and a Brachytherapy source demonstrate the proof-of-principle of the approach. The prototype achieves high spatial resolution of approximately 3 × 10{sup −5} m. The general approach is fundamentally independent of the radiation type and energy. The sensitivity range determined indicates that the method is predominantly suitable for high dose rate applications. Further work is required to determine absolute dose in all three dimensions.

Coherent noise reduction in digital holographic microscopy by averaging multiple holograms recorded with a multimode laser.

Science.gov (United States)

Pan, Feng; Yang, Lizhi; Xiao, Wen

2017-09-04

In digital holographic microscopy (DHM), it is undesirable to observe coherent noise in the reconstructed images. The sources of the noise are mainly the parasitic interference fringes caused by multiple reflections and the speckle pattern caused by the optical scattering on the object surface. Here we propose a noise reduction approach in DHM by averaging multiple holograms recorded with a multimode laser. Based on the periodicity of the temporal coherence of a multimode semiconductor laser, we acquire a series of holograms by changing the optical path length difference between the reference beam and object beam. Because of the use of low coherence light, we can remove the parasitic interference fringes caused by multiple reflections in the holograms. In addition, the coherent noise patterns change in this process due to the different optical paths. Therefore, the coherent noise can be reduced by averaging the multiple reconstructions with uncorrelated noise patterns. Several experiments have been carried out to validate the effectiveness of the proposed approach for coherent noise reduction in DHM. It is shown a remarkable improvement both in amplitude imaging quality and phase measurement accuracy.

Robust holographic storage system design.

Science.gov (United States)

Watanabe, Takahiro; Watanabe, Minoru

2011-11-21

Demand is increasing daily for large data storage systems that are useful for applications in spacecraft, space satellites, and space robots, which are all exposed to radiation-rich space environment. As candidates for use in space embedded systems, holographic storage systems are promising because they can easily provided the demanded large-storage capability. Particularly, holographic storage systems, which have no rotation mechanism, are demanded because they are virtually maintenance-free. Although a holographic memory itself is an extremely robust device even in a space radiation environment, its associated lasers and drive circuit devices are vulnerable. Such vulnerabilities sometimes engendered severe problems that prevent reading of all contents of the holographic memory, which is a turn-off failure mode of a laser array. This paper therefore presents a proposal for a recovery method for the turn-off failure mode of a laser array on a holographic storage system, and describes results of an experimental demonstration. © 2011 Optical Society of America

Characterization of liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system

Energy Technology Data Exchange (ETDEWEB)

Lombigit, L., E-mail: lojius@nm.gov.my; Yussup, N., E-mail: nolida@nm.gov.my; Ibrahim, Maslina Mohd; Rahman, Nur Aira Abd; Rawi, M. Z. M. [Instrumentation Group, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)

2015-04-29

A digital n/γ pulse shape discrimination (PSD) system is currently under development at Instrumentation and Automation Centre, Malaysian Nuclear Agency. This system aims at simultaneous detection of fast neutron and gamma ray in mixed radiations environment. This work reports the system characterization performed on the liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system. The characterization involves measurement of electron light output from the BC-501A detector and energy channels calibration of the pulse height spectra acquired with DPSD system using set of photon reference sources. The main goal of this experiment is to calibrate the ADC channel of our DPSD system, characterized the BC-501 detector and find the position of Compton edge which later could be used as threshold for the n/γ PSD experiment. The detector resolution however is worse as compared to other published data but it is expected as our detector has a smaller active volume.

Characterization of liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system

International Nuclear Information System (INIS)

Lombigit, L.; Yussup, N.; Ibrahim, Maslina Mohd; Rahman, Nur Aira Abd; Rawi, M. Z. M.

2015-01-01

A digital n/γ pulse shape discrimination (PSD) system is currently under development at Instrumentation and Automation Centre, Malaysian Nuclear Agency. This system aims at simultaneous detection of fast neutron and gamma ray in mixed radiations environment. This work reports the system characterization performed on the liquid scintillation detector (BC-501A) and digital pulse shape discrimination (DPSD) system. The characterization involves measurement of electron light output from the BC-501A detector and energy channels calibration of the pulse height spectra acquired with DPSD system using set of photon reference sources. The main goal of this experiment is to calibrate the ADC channel of our DPSD system, characterized the BC-501 detector and find the position of Compton edge which later could be used as threshold for the n/γ PSD experiment. The detector resolution however is worse as compared to other published data but it is expected as our detector has a smaller active volume

Adventures in holographic dimer models

International Nuclear Information System (INIS)

Kachru, Shamit; Karch, Andreas; Yaida, Sho

2011-01-01

We abstract the essential features of holographic dimer models, and develop several new applications of these models. Firstly, semi-holographically coupling free band fermions to holographic dimers, we uncover novel phase transitions between conventional Fermi liquids and non-Fermi liquids, accompanied by a change in the structure of the Fermi surface. Secondly, we make dimer vibrations propagate through the whole crystal by way of double trace deformations, obtaining nontrivial band structure. In a simple toy model, the topology of the band structure experiences an interesting reorganization as we vary the strength of the double trace deformations. Finally, we develop tools that would allow one to build, in a bottom-up fashion, a holographic avatar of the Hubbard model.

Fast neutron flux analyzer with real-time digital pulse shape discrimination

Energy Technology Data Exchange (ETDEWEB)

Ivanova, A.A., E-mail: a.a.ivanova@inp.nsk.su [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Zubarev, P.V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Ivanenko, S.V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Khilchenko, A.D. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Kotelnikov, A.I. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Polosatkin, S.V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Puryga, E.A.; Shvyrev, V.G. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation); Sulyaev, Yu.S. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 630090 Novosibirsk (Russian Federation)

2016-08-11

Investigation of subthermonuclear plasma confinement and heating in magnetic fusion devices such as GOL–3 and GDT at the Budker Institute (Novosibirsk, Russia) requires sophisticated equipment for neutron-, gamma- diagnostics and upgrading data acquisition systems with online data processing. Measurement of fast neutron flux with stilbene scintillation detectors raised the problem of discrimination of the neutrons (n) from background cosmic particles (muons) and neutron-induced gamma rays (γ). This paper describes a fast neutron flux analyzer with real-time digital pulse-shape discrimination (DPSD) algorithm FPGA-implemented for the GOL–3 and GDT devices. This analyzer was tested and calibrated with the help of {sup 137}Cs and {sup 252}Cf radiation sources. The Figures of Merit (FOM) calculated for different energy cuts are presented. - Highlights: • Electronic equipment for measurement of fast neutron flux with stilbene scintillator is presented. • FPGA-implemented digital pulse-shape discrimination algorithm by charge comparison method is shown. • Calibration of analyzer was carried out with {sup 137}Cs and {sup 252}Cf. • Figures of Merit (FOM) values for energy cuts from 1/8 Cs to 2 Cs are from 1.264 to 2.34 respectively.

Holographic complexity for time-dependent backgrounds

Energy Technology Data Exchange (ETDEWEB)

Momeni, Davood, E-mail: davoodmomeni78@gmail.com [Eurasian International Center for Theoretical Physics and Department of General Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Faizal, Mir, E-mail: mirfaizalmir@googlemail.com [Irving K. Barber School of Arts and Sciences, University of British Columbia, Okanagan, 3333 University Way, Kelowna, British Columbia V1V 1V7 (Canada); Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta, T1K 3M4 (Canada); Bahamonde, Sebastian, E-mail: sebastian.beltran.14@ucl.ac.uk [Department of Mathematics, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Myrzakulov, Ratbay [Eurasian International Center for Theoretical Physics and Department of General Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan)

2016-11-10

In this paper, we will analyze the holographic complexity for time-dependent asymptotically AdS geometries. We will first use a covariant zero mean curvature slicing of the time-dependent bulk geometries, and then use this co-dimension one spacelike slice of the bulk spacetime to define a co-dimension two minimal surface. The time-dependent holographic complexity will be defined using the volume enclosed by this minimal surface. This time-dependent holographic complexity will reduce to the usual holographic complexity for static geometries. We will analyze the time-dependence as a perturbation of the asymptotically AdS geometries. Thus, we will obtain time-dependent asymptotically AdS geometries, and we will calculate the holographic complexity for such time-dependent geometries.

Intelligent holographic databases

Science.gov (United States)

Barbastathis, George

Memory is a key component of intelligence. In the human brain, physical structure and functionality jointly provide diverse memory modalities at multiple time scales. How could we engineer artificial memories with similar faculties? In this thesis, we attack both hardware and algorithmic aspects of this problem. A good part is devoted to holographic memory architectures, because they meet high capacity and parallelism requirements. We develop and fully characterize shift multiplexing, a novel storage method that simplifies disk head design for holographic disks. We develop and optimize the design of compact refreshable holographic random access memories, showing several ways that 1 Tbit can be stored holographically in volume less than 1 m3, with surface density more than 20 times higher than conventional silicon DRAM integrated circuits. To address the issue of photorefractive volatility, we further develop the two-lambda (dual wavelength) method for shift multiplexing, and combine electrical fixing with angle multiplexing to demonstrate 1,000 multiplexed fixed holograms. Finally, we propose a noise model and an information theoretic metric to optimize the imaging system of a holographic memory, in terms of storage density and error rate. Motivated by the problem of interfacing sensors and memories to a complex system with limited computational resources, we construct a computer game of Desert Survival, built as a high-dimensional non-stationary virtual environment in a competitive setting. The efficacy of episodic learning, implemented as a reinforced Nearest Neighbor scheme, and the probability of winning against a control opponent improve significantly by concentrating the algorithmic effort to the virtual desert neighborhood that emerges as most significant at any time. The generalized computational model combines the autonomous neural network and von Neumann paradigms through a compact, dynamic central representation, which contains the most salient features

Separate recording of rationally related vibration frequencies using digital stroboscopic holographic interferometry

International Nuclear Information System (INIS)

Alexeenko, Igor; Gusev, Michael; Gurevich, Vadim

2009-01-01

A method for separate recording of rationally related vibration frequencies is presented. To record and measure the mode shape of vibrations, a synchronized stroboscopic CCD camera is used. Synchronization and control of the camera acquisition for recording stroboscopic holographic sequence has been realized. The phase for different states of the object vibration is calculated using the Fourier-transform method. Experimental results are presented, and the advantages and disadvantages of the proposed method are discussed.

Holographic kinetic k-essence model

Energy Technology Data Exchange (ETDEWEB)

Cruz, Norman [Departamento de Fisica, Facultad de Ciencia, Universidad de Santiago de Chile, Casilla 307, Santiago (Chile)], E-mail: ncruz@lauca.usach.cl; Gonzalez-Diaz, Pedro F.; Rozas-Fernandez, Alberto [Colina de los Chopos, Instituto de Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid (Spain)], E-mail: a.rozas@cfmac.csic.es; Sanchez, Guillermo [Departamento de Matematica y Ciencia de la Computacion, Facultad de Ciencia, Universidad de Santiago de Chile, Casilla 307, Santiago (Chile)], E-mail: gsanchez@usach.cl

2009-08-31

We consider a connection between the holographic dark energy density and the kinetic k-essence energy density in a flat FRW universe. With the choice c{>=}1, the holographic dark energy can be described by a kinetic k-essence scalar field in a certain way. In this Letter we show this kinetic k-essential description of the holographic dark energy with c{>=}1 and reconstruct the kinetic k-essence function F(X)

Application of Denisyuk pulsed holography to material testing

NARCIS (Netherlands)

Renesse, R.L. van; Burgmeijer, J.W.

1983-01-01

When holography is applied outside the laboratory, some well known problems are experienced: vibrations, rigid body motion, stray daylight. Pulse holography can overcome the difficulties with vibrations, but the other problems are less easily solved. When the object area to be holographically tested

Toward a holographic theory for general spacetimes

Science.gov (United States)

Nomura, Yasunori; Salzetta, Nico; Sanches, Fabio; Weinberg, Sean J.

2017-04-01

We study a holographic theory of general spacetimes that does not rely on the existence of asymptotic regions. This theory is to be formulated in a holographic space. When a semiclassical description is applicable, the holographic space is assumed to be a holographic screen: a codimension-1 surface that is capable of encoding states of the gravitational spacetime. Our analysis is guided by conjectured relationships between gravitational spacetime and quantum entanglement in the holographic description. To understand basic features of this picture, we catalog predictions for the holographic entanglement structure of cosmological spacetimes. We find that qualitative features of holographic entanglement entropies for such spacetimes differ from those in AdS/CFT but that the former reduce to the latter in the appropriate limit. The Hilbert space of the theory is analyzed, and two plausible structures are found: a direct-sum and "spacetime-equals-entanglement" structure. The former preserves a naive relationship between linear operators and observable quantities, while the latter respects a more direct connection between holographic entanglement and spacetime. We also discuss the issue of selecting a state in quantum gravity, in particular how the state of the multiverse may be selected in the landscape.

Proposal for a fast, zero suppressing circuit for the digitization of analog pulses over long memory times

International Nuclear Information System (INIS)

Bourgeois, F.

1984-01-01

This report describes the design principles of a fast (100 MHz) time and pulse height digitizer that can record up to 15 analog pulses over 10-80 μs memory times. Unlike other triggered circuits prepulse samples are recorded without the help of an analog delay line. The low power requirements of the circuit as well as its fast read-out characteristics make it very attractive for detectors with many digitizing channels. Conventional circuits are described as a reference for the evaluation of this new design. An ECL 10 K implementation of the circuit is presented in the third section. (orig.)

Digital in-line X-ray holography with zone plates.

Science.gov (United States)

Heine, R; Gorniak, T; Nisius, T; Christophis, C; Pettitt, M E; Staier, F; Wilhein, T; Rehbein, S; Grunze, M; Rosenhahn, A

2011-07-01

Single pulse imaging with radiation provided by free-electron laser sources is a promising approach towards X-ray microscopy, which is expected to provide high resolution images of biological samples unaffected by radiation damage. One fully coherent imaging technique for this purpose is digital in-line holography. Key to its successful application is the creation of X-ray point sources with high photon flux. In this study we applied zone plates to create such point sources with synchrotron radiation provided by the storage ring BESSY II. The obtained, divergent light cone is applied to holographic microscopy of biological objects such as critical point dried Navicula perminuta diatoms and human cells using photons with an energy of 250 eV. Compared to conventional experiments employing pinholes, exposure times are reduced by two orders of magnitude. Copyright © 2011 Elsevier B.V. All rights reserved.

Artistic Representation with Pulsed Holography

International Nuclear Information System (INIS)

Ishii, S

2013-01-01

This thesis describes artistic representation through pulsed holography. One of the prevalent practical problems in making holograms is object movement. Any movement of the object or film, including movement caused by acoustic vibration, has the same fatal results. One way of reducing the chance of movement is by ensuring that the exposure is very quick; using a pulsed laser can fulfill this objective. The attractiveness of using pulsed laser is based on the variety of materials or objects that can be recorded (e.g., liquid material or instantaneous scene of a moving object). One of the most interesting points about pulsed holograms is that some reconstructed images present us with completely different views of the real world. For example, the holographic image of liquid material does not appear fluid; it looks like a piece of hard glass that would produce a sharp sound upon tapping. In everyday life, we are unfamiliar with such an instantaneous scene. On the other hand, soft-textured materials such as a feather or wool differ from liquids when observed through holography. Using a pulsed hologram, we can sense the soft touch of the object or material with the help of realistic three-dimensional (3-D) images. The images allow us to realize the sense of touch in a way that resembles touching real objects. I had the opportunity to use a pulsed ruby laser soon after I started to work in the field of holography in 1979. Since then, I have made pulsed holograms of activities, including pouring water, breaking eggs, blowing soap bubbles, and scattering feathers and popcorn. I have also created holographic art with materials and objects, such as silk fiber, fabric, balloons, glass, flowers, and even the human body. Whenever I create art, I like to present the spectator with a new experience in perception. Therefore, I would like to introduce my experimental artwork through those pulsed holograms.

The holographic universe

CERN Document Server

Talbot, Michael

1991-01-01

'There is evidence to suggest that our world and everything in it - from snowflakes to maple trees to falling stars and spinning electrons - are only ghostly images, projections from a level of reality literally beyond both space and time.' This is the astonishing idea behind the holographic theory of the universe, pioneered by two eminent thinkers: physicist David Bohm, a former protege of Albert Einstein, and quantum physicist Karl Pribram. The holographic theory of the universe encompasses consciousness and reality as we know them, but can also explain such hitherto unexplained phenomena as telepathy, out-of-body experiences and even miraculous healing. In this remarkable book, Michael Talbot reveals the extraordinary depth and power of the holographic theory of the universe, illustrating how it makes sense of the entire range of experiences within our universe - and in other universes beyond our own.

Bubble nucleation dynamics in 3He/4He mixture by holographic interferometry

International Nuclear Information System (INIS)

Morikawa, M; Abe, H; Nomura, R; Okuda, Y

2009-01-01

We were able to nucleate a gas bubble in the diluted phase of 3 He- 4 He mixture by a 1 ms width strong sound pulse. The nucleated bubble became large and detached from the bottom transducer and was pushed out to the bulk liquid by the acoustic wave pulse. The bubble then repeatedly expanded and contracted a few times and finally disappeared. The overall motion of the bubble was traced by a high speed camera with a time resolution of 1 ms. We are attempting to investigate the small density fluctuation around the bubble by incorporating holographic interferometry technology. The measurement was done at T=0.35 K for the phase separated mixture at saturated vapor pressure. An acoustic wave transducer was located at the bottom of the cell, so the bubble was nucleated in the dilute phase of the mixture. We resolved the density fluctuation as small as Δρ/ρ = 2 x 10 -6 in the dilute phase with the sample width of 25 mm, which could not be obtained by other methods. It was found that there appeared a less dense region of -Δρ/ρ ∼ 1.46 x 10 -3 just above the bubble. The bubble appeared just after the pulse was turned off, but this less dense region appeared prior to the emergence of the bulk bubble. It should be an important information about the bubble nucleation mechanism. This very high sensitivity of holographic interferometry with respect to the density fluctuation could be widely used in quantum liquid.

Moving through a multiplex holographic scene

Science.gov (United States)

Mrongovius, Martina

2013-02-01

This paper explores how movement can be used as a compositional element in installations of multiplex holograms. My holographic images are created from montages of hand-held video and photo-sequences. These spatially dynamic compositions are visually complex but anchored to landmarks and hints of the capturing process - such as the appearance of the photographer's shadow - to establish a sense of connection to the holographic scene. Moving around in front of the hologram, the viewer animates the holographic scene. A perception of motion then results from the viewer's bodily awareness of physical motion and the visual reading of dynamics within the scene or movement of perspective through a virtual suggestion of space. By linking and transforming the physical motion of the viewer with the visual animation, the viewer's bodily awareness - including proprioception, balance and orientation - play into the holographic composition. How multiplex holography can be a tool for exploring coupled, cross-referenced and transformed perceptions of movement is demonstrated with a number of holographic image installations. Through this process I expanded my creative composition practice to consider how dynamic and spatial scenes can be conveyed through the fragmented view of a multiplex hologram. This body of work was developed through an installation art practice and was the basis of my recently completed doctoral thesis: 'The Emergent Holographic Scene — compositions of movement and affect using multiplex holographic images'.

Holographic renormalization and supersymmetry

Energy Technology Data Exchange (ETDEWEB)

Genolini, Pietro Benetti [Mathematical Institute, University of Oxford,Woodstock Road, Oxford OX2 6GG (United Kingdom); Cassani, Davide [LPTHE, Sorbonne Universités UPMC Paris 6 and CNRS, UMR 7589,F-75005, Paris (France); Martelli, Dario [Department of Mathematics, King’s College London,The Strand, London, WC2R 2LS (United Kingdom); Sparks, James [Mathematical Institute, University of Oxford,Woodstock Road, Oxford OX2 6GG (United Kingdom)

2017-02-27

Holographic renormalization is a systematic procedure for regulating divergences in observables in asymptotically locally AdS spacetimes. For dual boundary field theories which are supersymmetric it is natural to ask whether this defines a supersymmetric renormalization scheme. Recent results in localization have brought this question into sharp focus: rigid supersymmetry on a curved boundary requires specific geometric structures, and general arguments imply that BPS observables, such as the partition function, are invariant under certain deformations of these structures. One can then ask if the dual holographic observables are similarly invariant. We study this question in minimal N=2 gauged supergravity in four and five dimensions. In four dimensions we show that holographic renormalization precisely reproduces the expected field theory results. In five dimensions we find that no choice of standard holographic counterterms is compatible with supersymmetry, which leads us to introduce novel finite boundary terms. For a class of solutions satisfying certain topological assumptions we provide some independent tests of these new boundary terms, in particular showing that they reproduce the expected VEVs of conserved charges.

Holographic optical security systems

Science.gov (United States)

Fagan, William F.

1990-06-01

One of the most successful applications of Holography,in recent years,has been its use as an optical security technique.Indeed the general public's awareness of holograms has been greatly enhanced by the incorporation of holographic elements into the VISA and MASTERCHARGE credit cards.Optical techniques related to Holography,are also being used to protect the currencies of several countries against the counterfeiter. The mass production of high quality holographic images is by no means a trivial task as a considerable degree of expertise is required together with an optical laboratory and embossing machinery.This paper will present an overview of the principal holographic and related optical techniques used for security purposes.Worldwide, over thirty companies are involved in the production of security elements utilising holographic and related optical technologies.Counterfeiting of many products is a major criminal activity with severe consequences not only for the manufacturer but for the public in general as defective automobile parts,aircraft components,and pharmaceutical products, to cite only a few of the more prominent examples,have at one time or another been illegally copied.

The holographic entropy cone

Energy Technology Data Exchange (ETDEWEB)

Bao, Ning [Institute for Quantum Information and Matter, California Institute of Technology,Pasadena, CA 91125 (United States); Walter Burke Institute for Theoretical Physics, California Institute of Technology,452-48, Pasadena, CA 91125 (United States); Nezami, Sepehr [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94305 (United States); Ooguri, Hirosi [Walter Burke Institute for Theoretical Physics, California Institute of Technology,452-48, Pasadena, CA 91125 (United States); Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo,Kashiwa 277-8583 (Japan); Stoica, Bogdan [Walter Burke Institute for Theoretical Physics, California Institute of Technology,452-48, Pasadena, CA 91125 (United States); Sully, James [Theory Group, SLAC National Accelerator Laboratory, Stanford University,Menlo Park, CA 94025 (United States); Walter, Michael [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94305 (United States)

2015-09-21

We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phase space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.

The holographic entropy cone

International Nuclear Information System (INIS)

Bao, Ning; Nezami, Sepehr; Ooguri, Hirosi; Stoica, Bogdan; Sully, James; Walter, Michael

2015-01-01

We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phase space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.

Intelligent interaction based on holographic personalized portal

Directory of Open Access Journals (Sweden)

Yadong Huang

2017-06-01

Full Text Available Purpose – The purpose of this paper is to study the architecture of holographic personalized portal, user modeling, commodity modeling and intelligent interaction. Design/methodology/approach – In this paper, the authors propose crowd-science industrial ecological system based on holographic personalized portal and its interaction. The holographic personality portal is based on holographic enterprises, commodities and consumers, and the personalized portal consists of accurate ontology, reliable supply, intelligent demand and smart cyberspace. Findings – The personalized portal can realize the information acquisition, characteristic analysis and holographic presentation. Then, the intelligent interaction, e.g. demand decomposition, personalized search, personalized presentation and demand prediction, will be implemented within the personalized portal. Originality/value – The authors believe that their work on intelligent interaction based on holographic personalized portal, which has been first proposed in this paper, is innovation focusing on the interaction between intelligence and convenience.

Digitizing data acquisition and time-of-flight pulse processing for ToF-ERDA

Energy Technology Data Exchange (ETDEWEB)

Julin, Jaakko, E-mail: jaakko.julin@jyu.fi; Sajavaara, Timo

2016-01-01

A versatile system to capture and analyze signals from multi channel plate (MCP) based time-of-flight detectors and ionization based energy detectors such as silicon diodes and gas ionization chambers (GIC) is introduced. The system is based on commercial digitizers and custom software. It forms a part of a ToF-ERDA spectrometer, which has to be able to detect recoil atoms of many different species and energies. Compared to the currently used analogue electronics the digitizing system provides comparable time-of-flight resolution and improved hydrogen detection efficiency, while allowing the operation of the spectrometer be studied and optimized after the measurement. The hardware, data acquisition software and digital pulse processing algorithms to suit this application are described in detail.

Využití digitální holografické tomografie pro měření v oblasti přenosu tepla a hmoty

Czech Academy of Sciences Publication Activity Database

Doleček, Roman; Psota, Pavel; Lédl, Vít; Vít, T.

2017-01-01

Roč. 62, č. 1 (2017), s. 3-6 ISSN 0447-6441 R&D Projects: GA MŠk(CZ) LO1206 Institutional support: RVO:61389021 Keywords : digital holographic tomography * mass and heat transfer * temperature field measurement * digital holographic interferometry Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics)

Mapping the concentration changes during the dynamic processes of crevice corrosion by digital

Directory of Open Access Journals (Sweden)

HENGLEI JIA

2009-02-01

Full Text Available The dynamic process of crevice corrosion during anodic dissolution of a crevice electrode in a 5.0 mmol dm-3 NaCl solution has been studied by digital holographic reconstruction. Digital holographic reconstruction has been proved to be an effective and in situ technique to detect the changes in the solution concentration because useful and direct information can be obtained from the three-dimensional images. It provides a valuable method for a better understanding of the mechanism of crevice corrosion by studying the dynamic processes of changes in the solution concentration at the interface of crevice corrosion.

Digital Pulser for Characterization and Diagnostic of Digital Spectrometers

International Nuclear Information System (INIS)

Jordanov, V.T.

2013-01-01

The concept and the realization of the digital pulser are presented. The digital pulser is implemented as a functional block of a digital spectrometer. The digital pulser provides noise free and distortion free measurement of the inherent electronic noise of the entire spectroscopy system. The digital pulser is introduced at the end of the signal processing chain and allows separate evaluation of the individual spectroscopy blocks. It offers the ability to characterize and diagnose problems of the digital pulse height analysers by grounding their inputs. The digital pulser does not interfere with the processing of the detector signals and does not contribute to the dead time and the pulse pile-up of the system. The digital pulser peaks are not affected by the presence of detector pulses and are stored in a separate histogram memory leaving the detector spectrum undistorted. (author)

Holographic anyonic superfluidity

Science.gov (United States)

Jokela, Niko; Lifschytz, Gilad; Lippert, Matthew

2013-10-01

Starting with a holographic construction for a fractional quantum Hall state based on the D3-D7' system, we explore alternative quantization conditions for the bulk gauge fields. This gives a description of a quantum Hall state with various filling fractions. For a particular alternative quantization of the bulk gauge fields, we obtain a holographic anyon fluid in a vanishing background magnetic field. We show that this system is a superfluid, exhibiting the relevant gapless excitation.

The AdS/CFT Correspondence and Holographic QCD

International Nuclear Information System (INIS)

Erlich, J.

2012-01-01

Holographic QCD is an extra-dimensional approach to modeling QCD resonances and their interactions. Holographic models encode information about chiral symmetry breaking, Weinberg sum rules, vector meson dominance, and other phenomenological features of QCD. There are two complementary approaches to holographic model building: a top-down approach which begins with string-theory brane configurations, and a bottom-up approach which is more phenomenological. In this talk I will describe the AdS/CFT correspondence, which motivates Holographic QCD, and the techniques used to build holographic models of QCD and to calculate observables in those models. I will also discuss an intriguing light cone approach to Holographic QCD discovered by Brodsky and De Teramond. (author)

Optimal micro-mirror tilt angle and sync mark design for digital micro-mirror device based collinear holographic data storage system.

Science.gov (United States)

Liu, Jinpeng; Horimai, Hideyoshi; Lin, Xiao; Liu, Jinyan; Huang, Yong; Tan, Xiaodi

2017-06-01

The collinear holographic data storage system (CHDSS) is a very promising storage system due to its large storage capacities and high transfer rates in the era of big data. The digital micro-mirror device (DMD) as a spatial light modulator is the key device of the CHDSS due to its high speed, high precision, and broadband working range. To improve the system stability and performance, an optimal micro-mirror tilt angle was theoretically calculated and experimentally confirmed by analyzing the relationship between the tilt angle of the micro-mirror on the DMD and the power profiles of diffraction patterns of the DMD at the Fourier plane. In addition, we proposed a novel chess board sync mark design in the data page to reduce the system bit error rate in circumstances of reduced aperture required to decrease noise and median exposure amount. It will provide practical guidance for future DMD based CHDSS development.

Imaging the effect of hemoglobin on properties of RBCs using common-path digital holographic microscope

Science.gov (United States)

Joglekar, M.; Shah, H.; Trivedi, V.; Mahajan, S.; Chhaniwal, V.; Leitgeb, R.; Javidi, B.; Anand, A.

2017-07-01

Adequate supply of oxygen to the body is the most essential requirement. In vertebrate species this function is performed by Hemoglobin contained in red blood cells. The mass concentration of the Hb determines the oxygen carrying capacity of the blood. Thus it becomes necessary to determine its concentration in the blood, which helps in monitoring the health of a person. If the amount of Hb crosses certain range, then it is considered critical. As the Hb constitutes upto 96% of red blood cells dry content, it would be interesting to examine various physical and mechanical parameters of RBCs which depends upon its concentration. Various diseases bring about significant variation in the amount of hemoglobin which may alter certain parameters of the RBC such as surface area, volume, membrane fluctuation etc. The study of the variations of these parameters may be helpful in determining Hb content which will reflect the state of health of a human body leading to disease diagnosis. Any increase or decrease in the amount of Hb will change the density and hence the optical thickness of the RBCs, which affects the cell membrane and thereby changing its mechanical and physical properties. Here we describe the use of lateral shearing digital holographic microscope for quantifying the cell parameters for studying the change in biophysical properties of cells due to variation in hemoglobin concentration.

Holographic Spherically Symmetric Metrics

Science.gov (United States)

Petri, Michael

The holographic principle (HP) conjectures, that the maximum number of degrees of freedom of any realistic physical system is proportional to the system's boundary area. The HP has its roots in the study of black holes. It has recently been applied to cosmological solutions. In this article we apply the HP to spherically symmetric static space-times. We find that any regular spherically symmetric object saturating the HP is subject to tight constraints on the (interior) metric, energy-density, temperature and entropy-density. Whenever gravity can be described by a metric theory, gravity is macroscopically scale invariant and the laws of thermodynamics hold locally and globally, the (interior) metric of a regular holographic object is uniquely determined up to a constant factor and the interior matter-state must follow well defined scaling relations. When the metric theory of gravity is general relativity, the interior matter has an overall string equation of state (EOS) and a unique total energy-density. Thus the holographic metric derived in this article can serve as simple interior 4D realization of Mathur's string fuzzball proposal. Some properties of the holographic metric and its possible experimental verification are discussed. The geodesics of the holographic metric describe an isotropically expanding (or contracting) universe with a nearly homogeneous matter-distribution within the local Hubble volume. Due to the overall string EOS the active gravitational mass-density is zero, resulting in a coasting expansion with Ht = 1, which is compatible with the recent GRB-data.

Resolution enhancement of holographic printer using a hogel overlapping method.

Science.gov (United States)

Hong, Keehoon; Park, Soon-gi; Yeom, Jiwoon; Kim, Jonghyun; Chen, Ni; Pyun, Kyungsuk; Choi, Chilsung; Kim, Sunil; An, Jungkwuen; Lee, Hong-Seok; Chung, U-in; Lee, Byoungho

2013-06-17

We propose a hogel overlapping method for the holographic printer to enhance the lateral resolution of holographic stereograms. The hogel size is directly related to the lateral resolution of the holographic stereogram. Our analysis by computer simulation shows that there is a limit to decreasing the hogel size while printing holographic stereograms. Instead of reducing the size of hogel, the lateral resolution of holographic stereograms can be enhanced by printing overlapped hogels, which makes it possible to take advantage of multiplexing property of the volume hologram. We built a holographic printer, and recorded two holographic stereograms using the conventional and proposed overlapping methods. The images and movies of the holographic stereograms experimentally captured were compared between the conventional and proposed methods. The experimental results confirm that the proposed hogel overlapping method improves the lateral resolution of holographic stereograms compared to the conventional holographic printing method.

Holographic Entanglement Entropy

CERN Document Server

Rangamani, Mukund

2016-01-01

We review the developments in the past decade on holographic entanglement entropy, a subject that has garnered much attention owing to its potential to teach us about the emergence of spacetime in holography. We provide an introduction to the concept of entanglement entropy in quantum field theories, review the holographic proposals for computing the same, providing some justification for where these proposals arise from in the first two parts. The final part addresses recent developments linking entanglement and geometry. We provide an overview of the various arguments and technical developments that teach us how to use field theory entanglement to detect geometry. Our discussion is by design eclectic; we have chosen to focus on developments that appear to us most promising for further insights into the holographic map. This is a preliminary draft of a few chapters of a book which will appear sometime in the near future, to be published by Springer. The book in addition contains a discussion of application o...

Holographic complexity in gauge/string superconductors

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Davood Momeni

2016-05-01

Full Text Available Following a methodology similar to [1], we derive a holographic complexity for two dimensional holographic superconductors (gauge/string superconductors with backreactions. Applying a perturbation method proposed by Kanno in Ref. [2], we study behaviors of the complexity for a dual quantum system near critical points. We show that when a system moves from the normal phase (T>Tc to the superconductor phase (Tholographic complexity will be divergent.

Homodyne detection of holographic memory systems

Science.gov (United States)

Urness, Adam C.; Wilson, William L.; Ayres, Mark R.

2014-09-01

We present a homodyne detection system implemented for a page-wise holographic memory architecture. Homodyne detection by holographic memory systems enables phase quadrature multiplexing (doubling address space), and lower exposure times (increasing read transfer rates). It also enables phase modulation, which improves signal-to-noise ratio (SNR) to further increase data capacity. We believe this is the first experimental demonstration of homodyne detection for a page-wise holographic memory system suitable for a commercial design.

Entanglement entropy and complexity for one-dimensional holographic superconductors

Science.gov (United States)

Kord Zangeneh, Mahdi; Ong, Yen Chin; Wang, Bin

2017-08-01

Holographic superconductor is an important arena for holography, as it allows concrete calculations to further understand the dictionary between bulk physics and boundary physics. An important quantity of recent interest is the holographic complexity. Conflicting claims had been made in the literature concerning the behavior of holographic complexity during phase transition. We clarify this issue by performing a numerical study on one-dimensional holographic superconductor. Our investigation shows that holographic complexity does not behave in the same way as holographic entanglement entropy. Nevertheless, the universal terms of both quantities are finite and reflect the phase transition at the same critical temperature.

Parallel processing method for high-speed real time digital pulse processing for gamma-ray spectroscopy

International Nuclear Information System (INIS)

Fernandes, A.M.; Pereira, R.C.; Sousa, J.; Neto, A.; Carvalho, P.; Batista, A.J.N.; Carvalho, B.B.; Varandas, C.A.F.; Tardocchi, M.; Gorini, G.

2010-01-01

A new data acquisition (DAQ) system was developed to fulfil the requirements of the gamma-ray spectrometer (GRS) JET-EP2 (joint European Torus enhancement project 2), providing high-resolution spectroscopy at very high-count rate (up to few MHz). The system is based on the Advanced Telecommunications Computing Architecture TM (ATCA TM ) and includes a transient record (TR) module with 8 channels of 14 bits resolution at 400 MSamples/s (MSPS) sampling rate, 4 GB of local memory, and 2 field programmable gate array (FPGA) able to perform real time algorithms for data reduction and digital pulse processing. Although at 400 MSPS only fast programmable devices such as FPGAs can be used either for data processing and data transfer, FPGA resources also present speed limitation at some specific tasks, leading to an unavoidable data lost when demanding algorithms are applied. To overcome this problem and foreseeing an increase of the algorithm complexity, a new digital parallel filter was developed, aiming to perform real time pulse processing in the FPGAs of the TR module at the presented sampling rate. The filter is based on the conventional digital time-invariant trapezoidal shaper operating with parallelized data while performing pulse height analysis (PHA) and pile up rejection (PUR). The incoming sampled data is successively parallelized and fed into the processing algorithm block at one fourth of the sampling rate. The following data processing and data transfer is also performed at one fourth of the sampling rate. The algorithm based on data parallelization technique was implemented and tested at JET facilities, where a spectrum was obtained. Attending to the observed results, the PHA algorithm will be improved by implementing the pulse pile up discrimination.

Holographic interferometry of isolated deuterium plasmas produced by a CO2 laser

International Nuclear Information System (INIS)

Gatenby, P.V.; Walker, A.C.

1978-10-01

The application of double exposure fractional fringe holographic interferometry to measurements of electron density in a plasma generated by irradiation of a freely falling pellet of solid deuterium with a focused CO 2 laser pulse is discussed. A particularly simple technique is used for processing and reconstructing the holograms and this is described in detail. A summary and discussion of the results is included with the emphasis on the observed evolution of the deuterium plasma over the duration of the laser irradiation. (author)

A triple-crystal phoswich detector with digital pulse shape discrimination for alpha/beta/gamma spectroscopy

International Nuclear Information System (INIS)

White, Travis L.; Miller, William H.

1999-01-01

Researchers at the University of Missouri - Columbia have developed a three-crystal phoswich detector coupled to a digital pulse shape discrimination system for use in alpha/beta/gamma spectroscopy. Phoswich detectors use a sandwich of scintillators viewed by a single photomultiplier tube to simultaneously detect multiple types of radiation. Separation of radiation types is based upon pulse shape difference among the phosphors, which has historically been performed with analog circuitry. The system uses a GaGe CompuScope 1012, 12 bit, 10 MHz computer-based oscilloscope that digitally captures the pulses from a phoswich detector and subsequently performs pulse shape discrimination with cross-correlation analysis. The detector, based partially on previous phoswich designs by Usuda et al., uses a 10 mg/cm 2 thick layer of ZnS(Ag) for alpha detection, followed by a 0.254 cm CaF 2 (Eu) crystal for beta detection, all backed by a 2.54 cm NaI(Tl) crystal for gamma detection. Individual energy spectra and count rate information for all three radiation types are displayed and updated periodically. The system shows excellent charged particle discrimination with an accuracy of greater than 99%. Future development will include a large area beta probe with gamma-ray discrimination, systems for low-energy photon detection (e.g. Bremsstrahlung or keV-range photon emissions), and other health physics instrumentation

Holographic complexity and fidelity susceptibility as holographic information dual to different volumes in AdS

Directory of Open Access Journals (Sweden)

N.S. Mazhari

2017-03-01

Full Text Available The holographic complexity and fidelity susceptibility have been defined as new quantities dual to different volumes in AdS. In this paper, we will use these new proposals to calculate both of these quantities for a variety of interesting deformations of AdS. We obtain the holographic complexity and fidelity susceptibility for an AdS black hole, Janus solution, a solution with cylindrical symmetry, an inhomogeneous background and a hyperscaling violating background. It is observed that the holographic complexity depends on the size of the subsystem for all these solutions and the fidelity susceptibility does not have any such dependence.

Holographic complexity and fidelity susceptibility as holographic information dual to different volumes in AdS

Energy Technology Data Exchange (ETDEWEB)

Mazhari, N.S., E-mail: najmemazhari86@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Momeni, Davood, E-mail: davoodmomeni78@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Bahamonde, Sebastian, E-mail: sebastian.beltran.14@ucl.ac.uk [Department of Mathematics, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Faizal, Mir, E-mail: mirfaizalmir@googlemail.com [Irving K. Barber School of Arts and Sciences, University of British Columbia - Okanagan, 3333 University Way, Kelowna, British Columbia, V1V 1V7 (Canada); Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta, T1K 3M4 (Canada); Myrzakulov, Ratbay, E-mail: rmyrzakulov@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan)

2017-03-10

The holographic complexity and fidelity susceptibility have been defined as new quantities dual to different volumes in AdS. In this paper, we will use these new proposals to calculate both of these quantities for a variety of interesting deformations of AdS. We obtain the holographic complexity and fidelity susceptibility for an AdS black hole, Janus solution, a solution with cylindrical symmetry, an inhomogeneous background and a hyperscaling violating background. It is observed that the holographic complexity depends on the size of the subsystem for all these solutions and the fidelity susceptibility does not have any such dependence.

Inaccurate pulse CO-oximetry of carboxyhemoglobin due to digital clubbing: case report.

Science.gov (United States)

Harlan, Nicole; Weaver, Lindell K; Deru, Kayla

2016-01-01

Newer pulse CO-oximeters provide a non-invasive and quick means of measuring oxyhemoglobin, carboxyhemoglobin and methemoglobin. Clubbing has been reported to cause inaccuracy in pulse oximeters. We present a case of inaccurate carboxy-hemoglobin measurement by pulse CO-oximetry due to digital clubbing. An 18-year-old man with a history of cystic fibrosis presented after a suicide attempt by inhalation of exhaust. At the initial emergency department evaluation, his blood carboxyhemoglobin was 33%. He was intubated, placed on 100% oxygen and transferred to our facility. Upon arrival, we placed three different pulse CO-oximeters on different fingers and toes. Carboxyhemoglobin levels measured by these meters ranged from 9%-11%. A venous blood gas drawn on arrival showed a carboxyhemoglobin level of 2.3% after four hours on 100% oxygen by endotracheal tube. Thirty minutes later, we checked arterial blood gas, which revealed a COHb level of 0.9%. Again, non-invasive carboxyhemoglobin measurements read 10%. The patient was treated with hyperbaric oxygen for carbon monoxide poisoning. This case suggests that non-invasive measurements of carboxyhemoglobin should be correlated with the clinic history and with an arterial or venous blood gas oximetry analysis.

Full-field vibration measurements of the violin using digital stroboscopic holographic interferometry and electromagnetic stimulation of the strings

Science.gov (United States)

Keersmaekers, Lissa; Keustermans, William; De Greef, Daniël; Dirckx, Joris J. J.

2016-06-01

We developed a setup in which the strings of the violin are driven electromagnetically, and the resulting vibration of the instrument is measured with digital stroboscopic holography. A 250mW single mode green laser beam is chopped using an acousto-optic modulator, generating illumination pulses of 2% of the vibration period. The phase of the illumination pulse is controlled by a programmable function generator so that digital holograms can be recorded on a number of subsequent time positions within the vibration phase. From these recordings, the out of plane motion as a function of time is reconstructed in full field. We show results of full-field vibration amplitude and vibration phase maps, and time resolved full-field deformations of the violin back plane. Time resolved measurements show in detail how the deformation of the violin plane changes as a function of time at different frequencies. We found very different behavior under acoustic stimulation of the instrument and when using electromagnetic stimulation of a string. The aim of the work it to gather data which can be used in power flow calculations to study how the energy of the strings is conducted to the body of the violin and eventually is radiated as sound.

Full-field vibration measurements of the violin using digital stroboscopic holographic interferometry and electromagnetic stimulation of the strings

International Nuclear Information System (INIS)

Keersmaekers, Lissa; Keustermans, William; De Greef, Daniël; Dirckx, Joris J. J.

2016-01-01

We developed a setup in which the strings of the violin are driven electromagnetically, and the resulting vibration of the instrument is measured with digital stroboscopic holography. A 250 mW single mode green laser beam is chopped using an acousto-optic modulator, generating illumination pulses of 2% of the vibration period. The phase of the illumination pulse is controlled by a programmable function generator so that digital holograms can be recorded on a number of subsequent time positions within the vibration phase. From these recordings, the out of plane motion as a function of time is reconstructed in full field. We show results of full-field vibration amplitude and vibration phase maps, and time resolved full-field deformations of the violin back plane. Time resolved measurements show in detail how the deformation of the violin plane changes as a function of time at different frequencies. We found very different behavior under acoustic stimulation of the instrument and when using electromagnetic stimulation of a string. The aim of the work it to gather data which can be used in power flow calculations to study how the energy of the strings is conducted to the body of the violin and eventually is radiated as sound.

Full-field vibration measurements of the violin using digital stroboscopic holographic interferometry and electromagnetic stimulation of the strings

Energy Technology Data Exchange (ETDEWEB)

Keersmaekers, Lissa; Keustermans, William, E-mail: william.keustermans@uantwerpen.be; De Greef, Daniël; Dirckx, Joris J. J. [University of Antwerp, Laboratory of Biophysics and Biomedical Physics, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

2016-06-28

We developed a setup in which the strings of the violin are driven electromagnetically, and the resulting vibration of the instrument is measured with digital stroboscopic holography. A 250 mW single mode green laser beam is chopped using an acousto-optic modulator, generating illumination pulses of 2% of the vibration period. The phase of the illumination pulse is controlled by a programmable function generator so that digital holograms can be recorded on a number of subsequent time positions within the vibration phase. From these recordings, the out of plane motion as a function of time is reconstructed in full field. We show results of full-field vibration amplitude and vibration phase maps, and time resolved full-field deformations of the violin back plane. Time resolved measurements show in detail how the deformation of the violin plane changes as a function of time at different frequencies. We found very different behavior under acoustic stimulation of the instrument and when using electromagnetic stimulation of a string. The aim of the work it to gather data which can be used in power flow calculations to study how the energy of the strings is conducted to the body of the violin and eventually is radiated as sound.

Three-dimensional motion-picture imaging of dynamic object by parallel-phase-shifting digital holographic microscopy using an inverted magnification optical system

Science.gov (United States)

Fukuda, Takahito; Shinomura, Masato; Xia, Peng; Awatsuji, Yasuhiro; Nishio, Kenzo; Matoba, Osamu

2017-04-01

We constructed a parallel-phase-shifting digital holographic microscopy (PPSDHM) system using an inverted magnification optical system, and succeeded in three-dimensional (3D) motion-picture imaging for 3D displacement of a microscopic object. In the PPSDHM system, the inverted and afocal magnification optical system consisted of a microscope objective (16.56 mm focal length and 0.25 numerical aperture) and a convex lens (300 mm focal length and 82 mm aperture diameter). A polarization-imaging camera was used to record multiple phase-shifted holograms with a single-shot exposure. We recorded an alum crystal, sinking down in aqueous solution of alum, by the constructed PPSDHM system at 60 frames/s for about 20 s and reconstructed high-quality 3D motion-picture image of the crystal. Then, we calculated amounts of displacement of the crystal from the amounts in the focus plane and the magnifications of the magnification optical system, and obtained the 3D trajectory of the crystal by that amounts.

Holographic equipartition from first order action

Science.gov (United States)

Wang, Jingbo

2017-12-01

Recently, the idea that gravity is emergent has attract many people's attention. The "Emergent Gravity Paradigm" is a program that develop this idea from the thermodynamical point of view. It expresses the Einstein equation in the language of thermodynamics. A key equation in this paradigm is the holographic equipartition which says that, in all static spacetimes, the degrees of freedom on the boundary equal those in the bulk. And the time evolution of spacetime is drove by the departure from the holographic equipartition. In this paper, we get the holographic equipartition and its generalization from the first order formalism, that is, the connection and its conjugate momentum are considered to be the canonical variables. The final results have similar structure as those from the metric formalism. It gives another proof of holographic equipartition.

Ex-vivo holographic microscopy and spectroscopic analysis of head and neck cancer

Science.gov (United States)

Holler, Stephen; Wurtz, Robert; Auyeung, Kelsey; Auyeung, Kris; Paspaley-Grbavac, Milan; Mulroe, Brigid; Sobrero, Maximiliano; Miles, Brett

2015-03-01

Optical probes to identify tumor margins in vivo would greatly reduce the time, effort and complexity in the surgical removal of malignant tissue in head and neck cancers. Current approaches involve visual microscopy of stained tissue samples to determine cancer margins, which results in the excision of excess of tissue to assure complete removal of the cancer. Such surgical procedures and follow-on chemotherapy can adversely affect the patient's recovery and subsequent quality of life. In order to reduce the complexity of the process and minimize adverse effects on the patient, we investigate ex vivo tissue samples (stained and unstained) using digital holographic microscopy in conjunction with spectroscopic analyses (reflectance and transmission spectroscopy) in order to determine label-free, optically identifiable characteristic features that may ultimately be used for in vivo processing of cancerous tissues. The tissue samples studied were squamous cell carcinomas and associated controls from patients of varying age, gender and race. Holographic microscopic imaging scans across both cancerous and non-cancerous tissue samples yielded amplitude and phase reconstructions that were correlated with spectral signatures. Though the holographic reconstructions and measured spectra indicate variations even among the same class of tissue, preliminary results indicate the existence of some discriminating features. Further analyses are presently underway to further this work and extract additional information from the imaging and spectral data that may prove useful for in vivo surgical identification.

Controller for control of pulsed electron linear accelerator

International Nuclear Information System (INIS)

Bryazgin, A.A.; Faktorovich, B.L.

1995-01-01

The controller is based on the K1816VE31 microprocessor and contains 22-channel integrating 10-digital two-wire analog-to-digital converter, 8-channel 12-digit digital-to-analog converter, 24-digit output register, 16-digit input register pulse generator in the range of 0.5 - 50 Hz with the regulation step of 0.05 Hz and delayed pulse generator. The controller is used for pulsed electron linear accelerator control and is reduced to regulation of the electron beam pulse repetition rate and beam energy. 1 ref., 1 fig

Origin of holographic dark energy models

International Nuclear Information System (INIS)

Myung, Yun Soo; Seo, Min-Gyun

2009-01-01

We investigate the origin of holographic dark energy models which were recently proposed to explain the dark energy-dominated universe. For this purpose, we introduce the spacetime foam uncertainty of δl≥l p α l α-1 . It was argued that the case of α=2/3 could describe the dark energy with infinite statistics, while the case of α=1/2 can describe the ordinary matter with Bose-Fermi statistics. However, two cases may lead to the holographic energy density if the latter recovers from the geometric mean of UV and IR scales. Hence the dark energy with infinite statistics based on the entropy bound is not an ingredient for deriving the holographic dark energy model. Furthermore, it is shown that the agegraphic dark energy models are the holographic dark energy model with different IR length scales

Comprehensive time average digital holographic vibrometry

Czech Academy of Sciences Publication Activity Database

Psota, Pavel; Lédl, Vít; Doleček, Roman; Mokrý, P.; Vojtíšek, Petr; Václavík, J.

2016-01-01

Roč. 55, č. 12 (2016), č. článku 121726. ISSN 0091-3286 R&D Projects: GA ČR(CZ) GA16-11965S Institutional support: RVO:61389021 Keywords : vibration analysis * digital holography * frequency shifting * phase modulation * acousto-optic modulators Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.082, year: 2016 http://dx.doi.org/10.1117/1.oe.55.12.121726

Use of holographic environment in business and educational application

International Nuclear Information System (INIS)

Rajput, A.Q.K.; Shaikh, M.Z.; Khanzada, T.J.S.

2003-01-01

Holographic environment is based on high-equipped Multimedia information systems. These are based on the evolving powers of computers to handle huge volume of information. Holographic environment is a simulated environment that allows the user to touch and interact with projections, which are derived from the distant real environment. A new communications technology is being developed that will facilitate to interact inside a simulated environment, even if you are thousands of miles apart. This is done with enhancing the electro-holography, which is the computer based generation of diffraction fringes from 3D input data and the display of the reconstructed object in real-time. This research paper presents the design and development of holographic environment for reduction of distances in business and educational applications. The Holographic Environment development with the use of multimedia information systems is discussed. In Particular the characteristics of holographic data and the current research results in the area of real time holographic display systems are spanned. The Technical components of holographic system are also encountered. Finally, issues of improvement in efficiency of Holographic Environments by compression of data are presented along with its utilization for educational and business applications. (author)

A digital, constant-frequency pulsed phase-locked-loop instrument for real-time, absolute ultrasonic phase measurements

Science.gov (United States)

Haldren, H. A.; Perey, D. F.; Yost, W. T.; Cramer, K. E.; Gupta, M. C.

2018-05-01

A digitally controlled instrument for conducting single-frequency and swept-frequency ultrasonic phase measurements has been developed based on a constant-frequency pulsed phase-locked-loop (CFPPLL) design. This instrument uses a pair of direct digital synthesizers to generate an ultrasonically transceived tone-burst and an internal reference wave for phase comparison. Real-time, constant-frequency phase tracking in an interrogated specimen is possible with a resolution of 0.000 38 rad (0.022°), and swept-frequency phase measurements can be obtained. Using phase measurements, an absolute thickness in borosilicate glass is presented to show the instrument's efficacy, and these results are compared to conventional ultrasonic pulse-echo time-of-flight (ToF) measurements. The newly developed instrument predicted the thickness with a mean error of -0.04 μm and a standard deviation of error of 1.35 μm. Additionally, the CFPPLL instrument shows a lower measured phase error in the absence of changing temperature and couplant thickness than high-resolution cross-correlation ToF measurements at a similar signal-to-noise ratio. By showing higher accuracy and precision than conventional pulse-echo ToF measurements and lower phase errors than cross-correlation ToF measurements, the new digitally controlled CFPPLL instrument provides high-resolution absolute ultrasonic velocity or path-length measurements in solids or liquids, as well as tracking of material property changes with high sensitivity. The ability to obtain absolute phase measurements allows for many new applications than possible with previous ultrasonic pulsed phase-locked loop instruments. In addition to improved resolution, swept-frequency phase measurements add useful capability in measuring properties of layered structures, such as bonded joints, or materials which exhibit non-linear frequency-dependent behavior, such as dispersive media.

Energy resolution and throughput of a new real time digital pulse processing system for x-ray and gamma ray semiconductor detectors

International Nuclear Information System (INIS)

Abbene, L; Gerardi, G; Raso, G; Brai, M; Principato, F; Basile, S

2013-01-01

New generation spectroscopy systems have advanced towards digital pulse processing (DPP) approaches. DPP systems, based on direct digitizing and processing of detector signals, have recently been favoured over analog pulse processing electronics, ensuring higher flexibility, stability, lower dead time, higher throughput and better spectroscopic performance. In this work, we present the performance of a new real time DPP system for X-ray and gamma ray semiconductor detectors. The system is based on a commercial digitizer equipped with a custom DPP firmware, developed by our group, for on-line pulse shape and height analysis. X-ray and gamma ray spectra measurements with cadmium telluride (CdTe) and germanium (Ge) detectors, coupled to resistive-feedback preamplifiers, highlight the excellent performance of the system both at low and high rate environments (up to 800 kcps). A comparison with a conventional analog electronics showed the better high-rate capabilities of the digital approach, in terms of energy resolution and throughput. These results make the proposed DPP system a very attractive tool for both laboratory research and for the development of advanced detection systems for high-rate-resolution spectroscopic imaging, recently proposed in diagnostic medicine, industrial imaging and security screening

HOMES - Holographic Optical Method for Exoplanet Spectroscopy

Data.gov (United States)

National Aeronautics and Space Administration — HOMES (Holographic Optical Method for Exoplanet Spectroscopy) is a space telescope that employs a double dispersion architecture, using a holographic optical element...

Holographic characterization of colloidal particles in turbid media

Science.gov (United States)

Cheong, Fook Chiong; Kasimbeg, Priya; Ruffner, David B.; Hlaing, Ei Hnin; Blusewicz, Jaroslaw M.; Philips, Laura A.; Grier, David G.

2017-10-01

Holographic particle characterization uses in-line holographic microscopy and the Lorenz-Mie theory of light scattering to measure the diameter and the refractive index of individual colloidal particles in their native dispersions. This wealth of information has proved invaluable in fields as diverse as soft-matter physics, biopharmaceuticals, wastewater management, and food science but so far has been available only for dispersions in transparent media. Here, we demonstrate that holographic characterization can yield precise and accurate results even when the particles of interest are dispersed in turbid media. By elucidating how multiple light scattering contributes to image formation in holographic microscopy, we establish the range conditions under which holographic characterization can reliably probe turbid samples. We validate the technique with measurements on model colloidal spheres dispersed in commercial nanoparticle slurries.

Sol-Gel Glass Holographic Light-Shaping Diffusers

Science.gov (United States)

Yu, Kevin; Lee, Kang; Savant, Gajendra; Yin, Khin Swe (Lillian)

2005-01-01

Holographic glass light-shaping diffusers (GLSDs) are optical components for use in special-purpose illumination systems (see figure). When properly positioned with respect to lamps and areas to be illuminated, holographic GLSDs efficiently channel light from the lamps onto specified areas with specified distributions of illumination for example, uniform or nearly uniform irradiance can be concentrated with intensity confined to a peak a few degrees wide about normal incidence, over a circular or elliptical area. Holographic light diffusers were developed during the 1990s. The development of the present holographic GLSDs extends the prior development to incorporate sol-gel optical glass. To fabricate a holographic GLSD, one records a hologram on a sol-gel silica film formulated specially for this purpose. The hologram is a quasi-random, micro-sculpted pattern of smoothly varying changes in the index of refraction of the glass. The structures in this pattern act as an array of numerous miniature lenses that refract light passing through the GLSD, such that the transmitted light beam exhibits a precisely tailored energy distribution. In comparison with other light diffusers, holographic GLSDs function with remarkably high efficiency: they typically transmit 90 percent or more of the incident lamp light onto the designated areas. In addition, they can withstand temperatures in excess of 1,000 C. These characteristics make holographic GLSDs attractive for use in diverse lighting applications that involve high temperatures and/or requirements for high transmission efficiency for ultraviolet, visible, and near-infrared light. Examples include projectors, automobile headlights, aircraft landing lights, high-power laser illuminators, and industrial and scientific illuminators.

Gauge invariance and holographic renormalization

Directory of Open Access Journals (Sweden)

Keun-Young Kim

2015-10-01

Full Text Available We study the gauge invariance of physical observables in holographic theories under the local diffeomorphism. We find that gauge invariance is intimately related to the holographic renormalization: the local counter terms defined in the boundary cancel most of gauge dependences of the on-shell action as well as the divergences. There is a mismatch in the degrees of freedom between the bulk theory and the boundary one. We resolve this problem by noticing that there is a residual gauge symmetry (RGS. By extending the RGS such that it satisfies infalling boundary condition at the horizon, we can understand the problem in the context of general holographic embedding of a global symmetry at the boundary into the local gauge symmetry in the bulk.

Holographic measurement of distortion during laser melting: Additive distortion from overlapping pulses

Science.gov (United States)

Haglund, Peter; Frostevarg, Jan; Powell, John; Eriksson, Ingemar; Kaplan, Alexander F. H.

2018-03-01

Laser - material interactions such as welding, heat treatment and thermal bending generate thermal gradients which give rise to thermal stresses and strains which often result in a permanent distortion of the heated object. This paper investigates the thermal distortion response which results from pulsed laser surface melting of a stainless steel sheet. Pulsed holography has been used to accurately monitor, in real time, the out-of-plane distortion of stainless steel samples melted on one face by with both single and multiple laser pulses. It has been shown that surface melting by additional laser pulses increases the out of plane distortion of the sample without significantly increasing the melt depth. The distortion differences between the primary pulse and subsequent pulses has also been analysed for fully and partially overlapping laser pulses.

The Hubble IR cutoff in holographic ellipsoidal cosmologies

Energy Technology Data Exchange (ETDEWEB)

Cataldo, Mauricio [Universidad del Bio-Bio, Departamento de Fisica, Facultad de Ciencias, Concepcion (Chile); Cruz, Norman [Grupo de Cosmologia y Gravitacion-UBB, Concepcion (Chile)

2018-01-15

It is well known that for spatially flat FRW cosmologies, the holographic dark energy disfavors the Hubble parameter as a candidate for the IR cutoff. For overcoming this problem, we explore the use of this cutoff in holographic ellipsoidal cosmological models, and derive the general ellipsoidal metric induced by a such holographic energy density. Despite the drawbacks that this cutoff presents in homogeneous and isotropic universes, based on this general metric, we developed a suitable ellipsoidal holographic cosmological model, filled with a dark matter and a dark energy components. At late time stages, the cosmic evolution is dominated by a holographic anisotropic dark energy with barotropic equations of state. The cosmologies expand in all directions in accelerated manner. Since the ellipsoidal cosmologies given here are not asymptotically FRW, the deviation from homogeneity and isotropy of the universe on large cosmological scales remains constant during all cosmic evolution. This feature allows the studied holographic ellipsoidal cosmologies to be ruled by an equation of state ω = p/ρ, whose range belongs to quintessence or even phantom matter. (orig.)

Digital coherent detection research on Brillouin optical time domain reflectometry with simplex pulse codes

International Nuclear Information System (INIS)

Hao Yun-Qi; Ye Qing; Pan Zheng-Qing; Cai Hai-Wen; Qu Rong-Hui

2014-01-01

The digital coherent detection technique has been investigated without any frequency-scanning device in the Brillouin optical time domain reflectometry (BOTDR), where the simplex pulse codes are applied in the sensing system. The time domain signal of every code sequence is collected by the data acquisition card (DAQ). A shift-averaging technique is applied in the frequency domain for the reason that the local oscillator (LO) in the coherent detection is fix-frequency deviated from the primary source. With the 31-bit simplex code, the signal-to-noise ratio (SNR) has 3.5-dB enhancement with the same single pulse traces, accordant with the theoretical analysis. The frequency fluctuation for simplex codes is 14.01 MHz less than that for a single pulse as to 4-m spatial resolution. The results are believed to be beneficial for the BOTDR performance improvement. (general)

Characterization of the Micro-shell Surface Using Holographic Measurements

Energy Technology Data Exchange (ETDEWEB)

Sandras, F.; Hermerel, C.; Choux, A.; Merillot, P.; Pin, G.; Jeannot, L. [CEA Valduc, Dept Rech Mat Nucl, Serv Microcibles, 21 - Is-sur-Tille (France)

2009-05-15

To characterize the shape, the quality, and the roughness of micro-shells, typically used technologies are scanning electron microscopy, scanning interferometric microscopy, or atomic force microscopy. One of the drawbacks of these techniques is that they are generally slow because of their scanning process. Digital holographic microscopy technology is an innovation that can offer ability adapted to these studies. It captures holograms instead of intensity images, as done by conventional microscopes. The holograms are then digitally interpreted (10 per second) to reconstruct a double image, one for the intensity and another one for the phase. Using a rotation axis, the bump counting for the complete micro-shell surface is possible with a very high speed. Using an image stitching software, mapping can be done in a few minutes. Wavelets such as 'Mexican hat' are used to model the bumps. Each bump can then be characterized on the map by its position, diameter, and height. (authors)

Digital holographic amplification of interferograms in the Michelson interferometer using the phase-only LCOS modulator

Science.gov (United States)

Balbekin, Nikolay; Petrov, Nikolay; Pul'kin, Sergey; Shoev, Vladislav; Sevryugin, Alexander; Tursunov, Ibrohim; Venediktov, Dmitrii; Venediktov, Vladimir

2017-10-01

The method of amplification of hologram was applied to the so-called Rozhdestvenskiy hooks, that were obtained in the Rozhdestvenskiy interferometer (Michelson interferometer, combined with a grating spectrograph). In such a device the absorption lines reveal themselves as specific "hooks", whose curvature provides the information about the atomic oscillator force. The holographic amplification "smoothes" the hooks and thus makes their analysis much simpler.

Holographic Optical Data Storage

Science.gov (United States)

Timucin, Dogan A.; Downie, John D.; Norvig, Peter (Technical Monitor)

2000-01-01

Although the basic idea may be traced back to the earlier X-ray diffraction studies of Sir W. L. Bragg, the holographic method as we know it was invented by D. Gabor in 1948 as a two-step lensless imaging technique to enhance the resolution of electron microscopy, for which he received the 1971 Nobel Prize in physics. The distinctive feature of holography is the recording of the object phase variations that carry the depth information, which is lost in conventional photography where only the intensity (= squared amplitude) distribution of an object is captured. Since all photosensitive media necessarily respond to the intensity incident upon them, an ingenious way had to be found to convert object phase into intensity variations, and Gabor achieved this by introducing a coherent reference wave along with the object wave during exposure. Gabor's in-line recording scheme, however, required the object in question to be largely transmissive, and could provide only marginal image quality due to unwanted terms simultaneously reconstructed along with the desired wavefront. Further handicapped by the lack of a strong coherent light source, optical holography thus seemed fated to remain just another scientific curiosity, until the field was revolutionized in the early 1960s by some major breakthroughs: the proposition and demonstration of the laser principle, the introduction of off-axis holography, and the invention of volume holography. Consequently, the remainder of that decade saw an exponential growth in research on theory, practice, and applications of holography. Today, holography not only boasts a wide variety of scientific and technical applications (e.g., holographic interferometry for strain, vibration, and flow analysis, microscopy and high-resolution imagery, imaging through distorting media, optical interconnects, holographic optical elements, optical neural networks, three-dimensional displays, data storage, etc.), but has become a prominent am advertising

The use of linear programming techniques to design optimal digital filters for pulse shaping and channel equalization

Science.gov (United States)

Houts, R. C.; Burlage, D. W.

1972-01-01

A time domain technique is developed to design finite-duration impulse response digital filters using linear programming. Two related applications of this technique in data transmission systems are considered. The first is the design of pulse shaping digital filters to generate or detect signaling waveforms transmitted over bandlimited channels that are assumed to have ideal low pass or bandpass characteristics. The second is the design of digital filters to be used as preset equalizers in cascade with channels that have known impulse response characteristics. Example designs are presented which illustrate that excellent waveforms can be generated with frequency-sampling filters and the ease with which digital transversal filters can be designed for preset equalization.

[Improved detection of the pulse oximeter signal with a digital nerve block in patients in poor health status].

Science.gov (United States)

Cordoví de Armas, L; Espinaco Valdés, J; Jiménez Paneque, R E; Costa Hidalgo, T; Vallongo Menéndez, M B

2008-10-01

To demonstrate the efficacy of a digital nerve block for improving pulse oximetry in conditions of low tissue perfusion. A randomized single-blind study of adult patients undergoing surgery under general anesthesia for conditions characterized by hypoperfusion. Patients were assigned to a control group or an experimental group. The experimental group received a digital nerve block in the middle finger of the left hand; a sensor was then placed on the finger for between 120 and 300 minutes. Age, sex, diagnosis, total observation time (TOT), percentage of time with no pulse oximeter signal (NoPO), and percentage of time with an unstable pulse oximeter signal (UnstPO) were recorded. Each patient was questioned between 16 and 24 hours after surgery and was examined for flushing, paresthesia, hypoesthesia, pain, and ecchymosis. The chi2 test was used to compare dichotomized or nominal variables and the t test was used to compare age, TOT, NoPO, and UnstPO. Values of P<.05 were considered statistically significant in both cases. Fifty patients were randomized to each group. A total of 82 patients remained in the study (control group=42, experimental group=40). There were no significant between-group differences in diagnoses or TOT. The mean values for NoPO and UnstPO were higher in the control group than in the experimental group (11.1% vs 4.4% and 35.9% vs 15.7%, respectively; P<.001). A digital nerve block can be used to prevent pulse oximetry failures in conditions of low peripheral perfusion.

Refocusing criterion via sparsity measurements in digital holography.

Science.gov (United States)

Memmolo, Pasquale; Paturzo, Melania; Javidi, Bahram; Netti, Paolo A; Ferraro, Pietro

2014-08-15

Several automatic approaches have been proposed in the past to compute the refocus distance in digital holography (DH). However most of them are based on a maximization or minimization of a suitable amplitude image contrast measure, regarded as a function of the reconstruction distance parameter. Here we show that, by using the sparsity measure coefficient regarded as a refocusing criterion in the holographic reconstruction, it is possible to recover the focus plane and, at the same time, establish the degree of sparsity of digital holograms, when samples of the diffraction Fresnel propagation integral are used as a sparse signal representation. We employ a sparsity measurement coefficient known as Gini's index thus showing for the first time, to the best of our knowledge, its application in DH, as an effective refocusing criterion. Demonstration is provided for different holographic configurations (i.e., lens and lensless apparatus) and for completely different objects (i.e., a thin pure phase microscopic object as an in vitro cell, and macroscopic puppets) preparation.

The holographic Weyl semi-metal

Directory of Open Access Journals (Sweden)

Karl Landsteiner

2016-02-01

Full Text Available We present a holographic model of a Weyl semi-metal. We show the evidences that upon varying a mass parameter the model undergoes a sharp crossover at small temperature from a topologically non-trivial state to a trivial one. The order parameter is the anomalous Hall effect (AHE and we find that it is very strongly suppressed above a critical value of the mass parameter. This can be taken as a hint for an underlying topological quantum phase transition. We give an interpretation of the results in terms of a holographic RG flow and compare to a weakly coupled field theoretical model. Since there are no fermionic quasiparticle excitations in the strongly coupled holographic model the presence of an anomalous Hall effect cannot be bound to notions of topology in momentum spaces.

The holographic Weyl semi-metal

Energy Technology Data Exchange (ETDEWEB)

Landsteiner, Karl, E-mail: karl.landsteiner@csic.es; Liu, Yan, E-mail: yan.liu@csic.es

2016-02-10

We present a holographic model of a Weyl semi-metal. We show the evidences that upon varying a mass parameter the model undergoes a sharp crossover at small temperature from a topologically non-trivial state to a trivial one. The order parameter is the anomalous Hall effect (AHE) and we find that it is very strongly suppressed above a critical value of the mass parameter. This can be taken as a hint for an underlying topological quantum phase transition. We give an interpretation of the results in terms of a holographic RG flow and compare to a weakly coupled field theoretical model. Since there are no fermionic quasiparticle excitations in the strongly coupled holographic model the presence of an anomalous Hall effect cannot be bound to notions of topology in momentum spaces.

EDITORIAL: Optical tomography and digital holography

Science.gov (United States)

Coupland, Jeremy; Lobera, Julia

2008-07-01

The articles in this special feature in Measurement Science and Technology concern exciting new developments in the field of digital holography—the process of electronically recording and numerically reconstructing an optical field [1]. Making use of the enormous advances in digital imaging and computer technology, digital holography is presented in a range of applications from fluid flow measurement and structural analysis to medical imaging. The science of digital holography rests on the foundations of optical holography, on the work of Gabor in the late 1940s, and on the development of laser sources in the 1960s, which made his vision a practical reality [2]. Optical holography, however, uses a photosensitive material, both to record a latent image and subsequently to behave as a diffractive optical element with which to reconstruct the incident field. In this way display holograms, using silver halide materials for example, can produce life-size images that are virtually indistinguishable from the object itself [3]. Digital holography, in contrast, separates the steps of recording and reconstruction, and the final image is most often in the form of a 3D computer model. Of course, television cameras have been used from the beginnings of holography to record interferometric images. However, the huge disparity between the resolution of holographic recording materials (more than 3000 cycles/mm) and television cameras (around 50 cycles/mm) was raised as a major concern by early researchers. TV holography, as it was sometimes called, generally recorded low numerical aperture (NA) holograms producing images with characteristically large speckle and was therefore more often referred to as electronic speckle pattern interferomery (ESPI) [4]. It is possible, however, to record large NA holograms on a sensor with restricted resolution by using an objective lens or a diverging reference wave [5]. This is generally referred to as digital holographic microscopy (DHM) since

Current constraints on interacting holographic dark energy

International Nuclear Information System (INIS)

Wu Qiang; Gong Yungui; Wang Anzhong; Alcaniz, J.S.

2008-01-01

Although there is mounting observational evidence that the cosmic expansion is undergoing a late-time acceleration, the physical mechanism behind such a phenomenon is yet unknown. In this Letter, we investigate a holographic dark energy (HDE) model with interaction between the components of the dark sector in the light of current cosmological observations. We use both the new gold sample of 182 type Ia supernovae (SNe Ia) and the 192 SNe Ia ESSENCE data, the baryon acoustic oscillation measurement from the Sloan Digital Sky Survey and the shift parameter from the three-year Wilkinson Microwave Anisotropy Probe data. In agreement with previous results, we show that these observations suggest a very weak coupling or even a noninteracting HDE. The phantom crossing behavior in the context of these scenarios is also briefly discussed

Fidelity susceptibility as holographic PV-criticality

Energy Technology Data Exchange (ETDEWEB)

Momeni, Davood, E-mail: davoodmomeni78@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Faizal, Mir, E-mail: mirfaizalmir@googlemail.com [Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta T1K 3M4 (Canada); Irving K. Barber School of Arts and Sciences, University of British Columbia – Okanagan, 3333 University Way, Kelowna, British Columbia V1V 1V7 (Canada); Myrzakulov, Kairat, E-mail: kairatmyrzakul@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Myrzakulov, Ratbay, E-mail: rmyrzakulov@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan)

2017-02-10

It is well known that entropy can be used to holographically establish a connection among geometry, thermodynamics and information theory. In this paper, we will use complexity to holographically establish a connection among geometry, thermodynamics and information theory. Thus, we will analyze the relation among holographic complexity, fidelity susceptibility, and thermodynamics in extended phase space. We will demonstrate that fidelity susceptibility (which is the informational complexity dual to a maximum volume in AdS) can be related to the thermodynamical volume (which is conjugate to the cosmological constant in the extended thermodynamic phase space). Thus, this letter establishes a relation among geometry, thermodynamics, and information theory, using complexity.

Laser Digital Cinema

Science.gov (United States)

Takeuchi, Eric B.; Flint, Graham W.; Bergstedt, Robert; Solone, Paul J.; Lee, Dicky; Moulton, Peter F.

2001-03-01

Electronic cinema projectors are being developed that use a digital micromirror device (DMDTM) to produce the image. Photera Technologies has developed a new architecture that produces truly digital imagery using discrete pulse trains of red, green, and blue light in combination with a DMDTM where in the number of pulses that are delivered to the screen during a given frame can be defined in a purely digital fashion. To achieve this, a pulsed RGB laser technology pioneered by Q-Peak is combined with a novel projection architecture that we refer to as Laser Digital CameraTM. This architecture provides imagery wherein, during the time interval of each frame, individual pixels on the screen receive between zero and 255 discrete pulses of each color; a circumstance which yields 24-bit color. Greater color depth, or increased frame rate is achievable by increasing the pulse rate of the laser. Additionally, in the context of multi-screen theaters, a similar architecture permits our synchronously pulsed RGB source to simultaneously power three screens in a color sequential manner; thereby providing an efficient use of photons, together with the simplifications which derive from using a single DMDTM chip in each projector.

Higher order corrections to holographic black hole chemistry

Science.gov (United States)

Sinamuli, Musema; Mann, Robert B.

2017-10-01

We investigate the holographic Smarr relation beyond the large N limit. By making use of the holographic dictionary, we find that the bulk correlates of subleading 1 /N corrections to this relation are related to the couplings in Lovelock gravity theories. We likewise obtain a holographic equation of state and check its validity for a variety of interesting and nontrivial black holes, including rotating planar black holes in Gauss-Bonnet-Born-Infeld gravity, and nonextremal rotating black holes in minimal five-dimensional gauged supergravity. We provide an explanation of the N -dependence of the holographic Smarr relation in terms of contributions due to planar and nonplanar diagrams in the dual theory.

Detection of fast neutrons in a plastic scintillator using digital pulse processing to reject gammas

International Nuclear Information System (INIS)

Reeder, P.L.; Peurrung, A.J.; Hansen, R.R.; Stromswold, D.C.; Hensley, W.K.; Hubbard, C.W.

1999-01-01

We report on neutron-gamma discrimination in a plastic scintillator based on the time delay inherent in second and third chance neutron scattering. Because of the time delay (∼3 ns) between the first and second scattering of a neutron, calculations of gammas and neutrons in a plastic scintillator predict that a neutron signal should be significantly broader than a pulse from a gamma event. Experimentally, we have used a fast digital oscilloscope coupled to a computer to examine individual pulses from neutron or gamma induced signals in fast scintillators coupled to a fast PMT. Individual neutron-induced signals were consistent with the predictions of our model, but gamma pulses were broader than expected. We present various tests to understand this phenomenon and discuss a way to overcome this problem

Computer generated holographic microtags

International Nuclear Information System (INIS)

Sweatt, W.C.

1998-01-01

A microlithographic tag comprising an array of individual computer generated holographic patches having feature sizes between 250 and 75 nanometers is disclosed. The tag is a composite hologram made up of the individual holographic patches and contains identifying information when read out with a laser of the proper wavelength and at the proper angles of probing and reading. The patches are fabricated in a steep angle Littrow readout geometry to maximize returns in the -1 diffracted order. The tags are useful as anti-counterfeiting markers because of the extreme difficulty in reproducing them. 5 figs

Orthoscopic real-image display of digital holograms.

Science.gov (United States)

Makowski, P L; Kozacki, T; Zaperty, W

2017-10-01

We present a practical solution for the long-standing problem of depth inversion in real-image holographic display of digital holograms. It relies on a field lens inserted in front of the spatial light modulator device addressed by a properly processed hologram. The processing algorithm accounts for pixel size and wavelength mismatch between capture and display devices in a way that prevents image deformation. Complete images of large dimensions are observable from one position with a naked eye. We demonstrate the method experimentally on a 10-cm-long 3D object using a single full-HD spatial light modulator, but it can supplement most holographic displays designed to form a real image, including circular wide angle configurations.

A 16-channel real-time digital processor for pulse-shape discrimination in multiplicity assay

International Nuclear Information System (INIS)

Joyce, Malcolm J.; Aspinall, M.D.; Cave, F.D.; Lavietes, A.

2013-06-01

In recent years, real-time neutron/γ-ray pulse-shape discrimination has become feasible for use with scintillator-based detectors that respond extremely quickly, on the order of 25 ns in terms of pulse width, and their application to a variety of nuclear material assays has been reported. For the in-situ analysis of nuclear materials, measurements are often based on the multiplicity assessment of spontaneous fission events. An example of this is the 240 Pu eff assessment stemming from long-established techniques developed for 3 He-based neutron coincidence counters when 3 He was abundant and cheap. However, such measurements when using scintillator detectors can be plagued by low detection efficiencies and low orders of coincidence (often limited to triples) if the number of detectors in use is similarly limited to 3-4 detectors. Conversely, an array of >10 detector modules arranged to optimize efficiency and multiplicity sensitivity, shifts the emphasis in terms of performance requirement to the real-time digital analyzer and, critically, to the scope remaining in the temporal processing window of these systems. In this paper we report on the design, development and commissioning of a bespoke, 16-channel real-time pulse-shape discrimination analyzer specified for the materials assay challenge summarized above. The analyzer incorporates 16 dedicated and independent high-voltage supplies along with 16 independent digital processing channels offering pulse-shape discrimination at a rate of 3 x 10 6 events per second. These functions are configured from a dedicated graphical user interface, and all settings can be adjusted on-the-fly with the analyzer effectively configured one-time-only (where desired) for subsequent plug-and-play connection, for example to a fuel bundle organic scintillation detector array. (authors)

Comparing holographic dark energy models with statefinder

International Nuclear Information System (INIS)

Cui, Jing-Lei; Zhang, Jing-Fei

2014-01-01

We apply the statefinder diagnostic to the holographic dark energy models, including the original holographic dark energy (HDE) model, the new holographic dark energy model, the new agegraphic dark energy (NADE) model, and the Ricci dark energy model. In the low-redshift region the holographic dark energy models are degenerate with each other and with the ΛCDM model in the H(z) and q(z) evolutions. In particular, the HDE model is highly degenerate with the ΛCDM model, and in the HDE model the cases with different parameter values are also in strong degeneracy. Since the observational data are mainly within the low-redshift region, it is very important to break this lowredshift degeneracy in the H(z) and q(z) diagnostics by using some quantities with higher order derivatives of the scale factor. It is shown that the statefinder diagnostic r(z) is very useful in breaking the low-redshift degeneracies. By employing the statefinder diagnostic the holographic dark energy models can be differentiated efficiently in the low-redshift region. The degeneracy between the holographic dark energy models and the ΛCDM model can also be broken by this method. Especially for the HDE model, all the previous strong degeneracies appearing in the H(z) and q(z) diagnostics are broken effectively. But for the NADE model, the degeneracy between the cases with different parameter values cannot be broken, even though the statefinder diagnostic is used. A direct comparison of the holographic dark energy models in the r-s plane is also made, in which the separations between the models (including the ΛCDM model) can be directly measured in the light of the current values {r 0 , s 0 } of the models. (orig.)

Measurements of absorbed energy distributions in water from pulsed electron beams

International Nuclear Information System (INIS)

Devanney, J.A.

1974-01-01

An evaluation of the use of a holographic interferometer to measure the energy deposition as a function of depth in water from pulsed electron beams, together with a brief description of the interferometer and the technique of generating a hologram are presented. The holographic interferometer is used to measure the energy deposition as a function of depth in water from various pulsed beams of monoenergetic electrons in the energy range from 1.0 to 2.5 MeV. These results are compared to those computed by using a Monte Carlo radiation transport code, ETRAN-15, for the same electron energies. After the discrepancies between the measured and computed results are evaluated, reasonable agreement is found between the measured and computed absorbed energy distributions as a function of depth in water. An evalutation of the response of the interferometer as a function of electron intensities is performed. A comparison among four energy deposition curves that result from the irradiation of water with pulsed electron beams from a Febetron accelerator, model 705, is presented. These pulsed beams were produced by the same vacuum diode with the same charging voltage. The results indicate that the energy distribution of the electrons in the pulsed beam is not always constant. A comparison of the energy deposition curves that result from the irradiation of water with electron pulses from different vacuum diodes but the same charging voltage is presented. These results indicate again that the energy distribution of the electrons in the pulsed beam may vary between vacuum diodes. These differences would not be realized by using a totally absorbing metal calorimeter and Faraday Cup

Digitally controlled chirped pulse laser for sub-terahertz-range fiber structure interrogation.

Science.gov (United States)

Chen, Zhen; Hefferman, Gerald; Wei, Tao

2017-03-01

This Letter reports a sweep velocity-locked laser pulse generator controlled using a digital phase-locked loop (DPLL) circuit. This design is used for the interrogation of sub-terahertz-range fiber structures for sensing applications that require real-time data collection with millimeter-level spatial resolution. A distributed feedback laser was employed to generate chirped laser pulses via injection current modulation. A DPLL circuit was developed to lock the optical frequency sweep velocity. A high-quality linearly chirped laser pulse with a frequency excursion of 117.69 GHz at an optical communication band was demonstrated. The system was further adopted to interrogate a continuously distributed sub-terahertz-range fiber structure (sub-THz-fs) for sensing applications. A strain test was conducted in which the sub-THz-fs showed a linear response to longitudinal strain change with predicted sensitivity. Additionally, temperature testing was conducted in which a heat source was used to generate a temperature distribution along the fiber structure to demonstrate its distributed sensing capability. A Gaussian temperature profile was measured using the described system and tracked in real time, as the heat source was moved.

On new proposal for holographic BCFT

Energy Technology Data Exchange (ETDEWEB)

Chu, Chong-Sun; Miao, Rong-Xin [Department of Physics, National Tsing-Hua University,Hsinchu 30013, Taiwan (China); Physics Division, National Center for Theoretical Sciences,National Tsing-Hua University, Hsinchu 30013, Taiwan (China); Guo, Wu-Zhong [Physics Division, National Center for Theoretical Sciences,National Tsing-Hua University, Hsinchu 30013, Taiwan (China)

2017-04-14

This paper is an extended version of our short letter on a new proposal for holographic boundary conformal field, i.e., BCFT. By using the Penrose-Brown-Henneaux (PBH) transformation, we successfully obtain the expected boundary Weyl anomaly. The obtained boundary central charges satisfy naturally a c-like theorem holographically. We then develop an approach of holographic renormalization for BCFT, and reproduce the correct boundary Weyl anomaly. This provides a non-trivial check of our proposal. We also investigate the holographic entanglement entropy of BCFT and find that our proposal gives the expected orthogonal condition that the minimal surface must be normal to the spacetime boundaries if they intersect. This is another support for our proposal. We also find that the entanglement entropy depends on the boundary conditions of BCFT and the distance to the boundary; and that the entanglement wedge behaves a phase transition, which is important for the self-consistency of AdS/BCFT. Finally, we show that the proposal of https://arxiv.org/abs/1105.5165 is too restrictive that it always make vanishing some of the boundary central charges.

Dual-Wavelength Sensitized Photopolymer for Holographic Data Storage

Science.gov (United States)

Tao, Shiquan; Zhao, Yuxia; Wan, Yuhong; Zhai, Qianli; Liu, Pengfei; Wang, Dayong; Wu, Feipeng

2010-08-01

Novel photopolymers for holographic storage were investigated by combining acrylate monomers and/or vinyl monomers as recording media and liquid epoxy resins plus an amine harder as binder. In order to improve the holographic performances of the material at blue-green wavelength band two novel dyes were used as sensitizer. The methods of evaluating the holographic performances of the material, including the shrinkage and noise characteristics, are described in detail. Preliminary experiments show that samples with optimized composite have good holographic performances, and it is possible to record dual-wavelength hologram simultaneously in this photopolymer by sharing the same optical system, thus the storage density and data rate can be doubly increased.

Holographic correlation functions in Critical Gravity

Science.gov (United States)

Anastasiou, Giorgos; Olea, Rodrigo

2017-11-01

We compute the holographic stress tensor and the logarithmic energy-momentum tensor of Einstein-Weyl gravity at the critical point. This computation is carried out performing a holographic expansion in a bulk action supplemented by the Gauss-Bonnet term with a fixed coupling. The renormalization scheme defined by the addition of this topological term has the remarkable feature that all Einstein modes are identically cancelled both from the action and its variation. Thus, what remains comes from a nonvanishing Bach tensor, which accounts for non-Einstein modes associated to logarithmic terms which appear in the expansion of the metric. In particular, we compute the holographic 1-point functions for a generic boundary geometric source.

Digital pulse shape discrimination between fast neutrons and gamma rays with para-terphenyl scintillator

Science.gov (United States)

Chepurnov, A. S.; Kirsanov, M. A.; Klenin, A. A.; Klimanov, S. G.; Kubankin, A. S.

2017-12-01

In the presented work, we investigated several digital methods of a discrimination signals from fast neutrons and gamma quanta. The experimental setup consists of a Pu-Be neutron source, a scintillation detector with an organic para-terphenyl monocrystal, and a digitizer (CAEN DT5730, 500 MS/s). Mixed waveform sequences were stored and then separated by pulse shape. Four methods were used for signals separation. Comparison of the traditional and the new methods of Figure of Merit (FOM) calculation is given. FOM = 1.5 was obtained in our setup for the minimum threshold value. A scintillation detector with a para-terphenyl crystal was used to measure neutron yield in the neutron generator with carbon nanotubes.

Research on copying system of dynamic multiplex holographic stereograms

Science.gov (United States)

Fu, Huaiping; Yang, Hong; Zheng, Tong

2003-05-01

The most important advantage of holographic stereograms over conventional hologram is that they can produce 3D images at any desired scale with movement, holographers in many countries involved in the studies towards it. We began our works in the early 80's and accomplished two research projects automatic system for making synthetic holograms and multiplex synthetic rainbow holograms, Based on these works, a large scale holographic stereogram of an animated goldfish was made by us for practical advertisement. In order to meet the needs of the market, a copying system for making multiplex holographic stereograms, and a special kind of silver halide holographic film developed by us recently. The characteristic of the copying system and the property of the special silver-halide emulsion are introduced in this paper.

DHM (Digital Holography Microscope) for imaging cells

International Nuclear Information System (INIS)

Emery, Yves; Cuche, Etienne; Colomb, Tristan; Depeursinge, Christian; Rappaz, Benjamin; Marquet, Pierre; Magistretti, Pierre

2007-01-01

Light interaction with a sample modifies both intensity and phase of the illuminating wave. Any available supports for image recording are only sensitive to intensity, but Denis Gabor [P. Marquet, B. Rappaz, P. Magistretti, et. al. Digital Holography for quantitative phase-contrast imaging, Optics Letters, 30, 5, pp 291-93 (2005)] invented in 1948 a way to encode the phase as an intensity variation: the h ologram . Digital Holographic Microscopy (DHM) [D. Gabor, A new microscopic principle, Nature, 1948] implements digitally this powerful hologram. Characterization of various pollen grains and of morphology changes of neurones associated with hypotonic shock demonstrates the potential of DHM for imaging cells

Improving image quality of parallel phase-shifting digital holography

International Nuclear Information System (INIS)

Awatsuji, Yasuhiro; Tahara, Tatsuki; Kaneko, Atsushi; Koyama, Takamasa; Nishio, Kenzo; Ura, Shogo; Kubota, Toshihiro; Matoba, Osamu

2008-01-01

The authors propose parallel two-step phase-shifting digital holography to improve the image quality of parallel phase-shifting digital holography. The proposed technique can increase the effective number of pixels of hologram twice in comparison to the conventional parallel four-step technique. The increase of the number of pixels makes it possible to improve the image quality of the reconstructed image of the parallel phase-shifting digital holography. Numerical simulation and preliminary experiment of the proposed technique were conducted and the effectiveness of the technique was confirmed. The proposed technique is more practical than the conventional parallel phase-shifting digital holography, because the composition of the digital holographic system based on the proposed technique is simpler.

Power quality improvement by using multi-pulse AC-DC converters for DC drives: Modeling, simulation and its digital implementation

Directory of Open Access Journals (Sweden)

Mohd Tariq

2014-12-01

Full Text Available The paper presents the modeling, simulation and digital implementation of power quality improvement of DC drives by using multi pulse AC–DC converter. As it is a well-known fact that power quality determines the fitness of electrical power to consumer devices, hence an effort has been made to improve power quality in this work. Simulation and digital implementation with the help of MATLAB/Simulink has been done and results obtained are discussed in detail to verify the theoretical results. The multipulse converter was connected with DC drives and was run at no load condition to find out the transient and steady state performances. FFT analysis has been performed and Total Harmonic Distortion (THD results obtained at different pulses are shown here.

Extended ABCD matrix formalism for the description of femtosecond diffraction patterns; application to femtosecond digital in-line holography with anamorphic optical systems.

Science.gov (United States)

Brunel, Marc; Shen, Huanhuan; Coetmellec, Sebastien; Lebrun, Denis

2012-03-10

We present a new model to predict diffraction patterns of femtosecond pulses through complex optical systems. The model is based on the extension of an ABCD matrix formalism combined with generalized Huygens-Fresnel transforms (already used in the CW regime) to the femtosecond regime. The model is tested to describe femtosecond digital in-line holography experiments realized in situ through a cylindrical Plexiglas pipe. The model allows us to establish analytical relations that link the holographic reconstruction process to the experimental parameters of the pipe and of the incident beam itself. Simulations and experimental results are in good concordance. Femtosecond digital in-line holography is shown to allow significant coherent noise reduction, and this model will be particularly efficient to describe a wide range of optical geometries. More generally, the model developed can be easily used in any experiment where the knowledge of the precise evolution of femtosecond transverse patterns is required.

Biophotopol: A Sustainable Photopolymer for Holographic Data Storage Applications

Directory of Open Access Journals (Sweden)

Augusto Beléndez

2012-05-01

Full Text Available Photopolymers have proved to be useful for different holographic applications such as holographic data storage or holographic optical elements. However, most photopolymers have certain undesirable features, such as the toxicity of some of their components or their low environmental compatibility. For this reason, the Holography and Optical Processing Group at the University of Alicante developed a new dry photopolymer with low toxicity and high thickness called biophotopol, which is very adequate for holographic data storage applications. In this paper we describe our recent studies on biophotopol and the main characteristics of this material.

Interacting holographic dark energy in Brans-Dicke theory

International Nuclear Information System (INIS)

Sheykhi, Ahmad

2009-01-01

We study cosmological application of interacting holographic energy density in the framework of Brans-Dicke cosmology. We obtain the equation of state and the deceleration parameter of the holographic dark energy in a non-flat universe. As system's IR cutoff we choose the radius of the event horizon measured on the sphere of the horizon, defined as L=ar(t). We find that the combination of Brans-Dicke field and holographic dark energy can accommodate w D =-1 crossing for the equation of state of noninteracting holographic dark energy. When an interaction between dark energy and dark matter is taken into account, the transition of w D to phantom regime can be more easily accounted for than when resort to the Einstein field equations is made.

Holographic patterning of organic-inorganic photopolymerizable nanocomposites

Science.gov (United States)

Sakhno, Oksana V.; Goldenberg, Leonid M.; Smirnova, Tatiana N.; Stumpe, J.

2009-09-01

We present here novel easily processible organic-inorganic nanocomposites suitable for holographic fabrication of diffraction optical elements (DOE). The nanocomposites are based on photocurable acrylate monomers and inorganic nanoparticles (NP). The compatibility of inorganic NP with monomers was achieved by capping the NP surface with proper organic shells. Surface modification allows to introduce up to 50wt.% of inorganic NP in organic media. Depending on the NP nature (metal oxides, phosphates, semiconductors, noble metals) and their properties, the materials for both efficient DOE and multifunctional elements can be designed. Organic-inorganic composites prepared have been successfully used for the effective inscription of periodic volume refractive index structures using the holographic photopolymerization method. The nanocomposite preparation procedure, their properties and optical performance of holographic gratings are reported. The use of functional NP makes it possible to obtain effective holographic gratings having additional physical properties such as light-emission or NLO. Some examples of such functional polymer-NP structures and their possible application fields are presented. The combination of easy photo-patterning of soft organic compounds with physical properties of inorganic materials in new nanocomposites and the flexibility of the holographic patterning method allow the fabrication of mono- and multifunctional one- and multi-dimensional passive or active optical and photonic elements.

Digital voltmeter

International Nuclear Information System (INIS)

Yohannes Kamadi; Soekarno.

1976-01-01

The electrical voltage measuring equipment with digital display has been made. This equipment uses four digits display with single polarity measurement and integrating system. Pulses from the oscillator will be counted and converted to the staircase voltages, and compared to the voltage measured. When the balance is already achieved, the pulse will appear at the comparator circuit. This pulse will be used to trigger univibrator circuit. The univibrator output is used as signal for stopping the counting, and when reading time T already stops, the counting system will be reset. (authors)

Anomalous transport and holographic momentum relaxation

Science.gov (United States)

Copetti, Christian; Fernández-Pendás, Jorge; Landsteiner, Karl; Megías, Eugenio

2017-09-01

The chiral magnetic and vortical effects denote the generation of dissipationless currents due to magnetic fields or rotation. They can be studied in holographic models with Chern-Simons couplings dual to anomalies in field theory. We study a holographic model with translation symmetry breaking based on linear massless scalar field backgrounds. We compute the electric DC conductivity and find that it can vanish for certain values of the translation symmetry breaking couplings. Then we compute the chiral magnetic and chiral vortical conductivities. They are completely independent of the holographic disorder couplings and take the usual values in terms of chemical potential and temperature. To arrive at this result we suggest a new definition of energy-momentum tensor in presence of the gravitational Chern-Simons coupling.

Holographic data storage: science fiction or science fact?

Science.gov (United States)

Anderson, Ken; Ayres, Mark; Askham, Fred; Sissom, Brad

2014-09-01

To compete in the archive and backup industries, holographic data storage must be highly competitive in four critical areas: total cost of ownership (TCO), cost/TB, capacity/footprint, and transfer rate. New holographic technology advancements by Akonia Holographics have enabled the potential for ultra-high capacity holographic storage devices that are capable of world record bit densities of over 2-4Tbit/in2, up to 200MB/s transfer rates, and media costs less than $10/TB in the next few years. Additional advantages include more than a 3x lower TCO than LTO, a 3.5x decrease in volumetric footprint, 30ms random access times, and 50 year archive life. At these bit densities, 4.5 Petabytes of uncompressed user data could be stored in a 19" rack system. A demonstration platform based on these new advances has been designed and built by Akonia to progressively demonstrate bit densities of 2Tb/in2, 4Tb/in2, and 8Tb/in2 over the next year. Keywords: holographic

Random pulse generator

International Nuclear Information System (INIS)

Guo Ya'nan; Jin Dapeng; Zhao Dixin; Liu Zhen'an; Qiao Qiao; Chinese Academy of Sciences, Beijing

2007-01-01

Due to the randomness of radioactive decay and nuclear reaction, the signals from detectors are random in time. But normal pulse generator generates periodical pulses. To measure the performances of nuclear electronic devices under random inputs, a random generator is necessary. Types of random pulse generator are reviewed, 2 digital random pulse generators are introduced. (authors)

High-throughput characterization of stresses in thin film materials libraries using Si cantilever array wafers and digital holographic microscopy

International Nuclear Information System (INIS)

Lai, Y. W.; Ludwig, A.; Hamann, S.; Ehmann, M.

2011-01-01

We report the development of an advanced high-throughput stress characterization method for thin film materials libraries sputter-deposited on micro-machined cantilever arrays consisting of around 1500 cantilevers on 4-inch silicon-on-insulator wafers. A low-cost custom-designed digital holographic microscope (DHM) is employed to simultaneously monitor the thin film thickness, the surface topography and the curvature of each of the cantilevers before and after deposition. The variation in stress state across the thin film materials library is then calculated by Stoney's equation based on the obtained radii of curvature of the cantilevers and film thicknesses. DHM with nanometer-scale out-of-plane resolution allows stress measurements in a wide range, at least from several MPa to several GPa. By using an automatic x-y translation stage, the local stresses within a 4-inch materials library are mapped with high accuracy within 10 min. The speed of measurement is greatly improved compared with the prior laser scanning approach that needs more than an hour of measuring time. A high-throughput stress measurement of an as-deposited Fe-Pd-W materials library was evaluated for demonstration. The fast characterization method is expected to accelerate the development of (functional) thin films, e.g., (magnetic) shape memory materials, whose functionality is greatly stress dependent.

The shifting appearance/disappearance of holographic images and the dynamic ontology of perceptual and cognitive processes

Science.gov (United States)

Boissonnet, Philippe

2013-02-01

The French philosopher M Merleau-Ponty captured the dynamic of perception with his idea of the intertwining of perceiver and perceived. Light is what links them. In the case of holographic images, not only is spatial and colour perception the pure product of light, but this light information is always in the process of self-construction with our eyes, according to our movements and the point of view adopted. According to the aesthetic reception of a work of art, Holographic images vary greatly from those of cinema, photography and even every kind of digital 3D animation. This particular image's status truly makes perceptually apparent the "co-emergence" of light and our gaze. But holography never misleads us with respect to the precarious nature of our perceptions. We have no illusion as to the limits of our empirical understanding of the perceived reality. Holography, like our knowledge of the visible, thus brings to light the phenomenon of reality's "co-constitution" and contributes to a dynamic ontology of perceptual and cognitive processes. The cognitivist Francico Varela defines this as the paradigm of enaction,i which I will adapt and apply to the appearance/disappearance context of holographic images to bring out their affinities on a metaphorical level.

Holographic memories with encryption-selectable function

Science.gov (United States)

Su, Wei-Chia; Lee, Xuan-Hao

2006-03-01

Volume holographic storage has received increasing attention owing to its potential high storage capacity and access rate. In the meanwhile, encrypted holographic memory using random phase encoding technique is attractive for an optical community due to growing demand for protection of information. In this paper, encryption-selectable holographic storage algorithms in LiNbO 3 using angular multiplexing are proposed and demonstrated. Encryption-selectable holographic memory is an advance concept of security storage for content protection. It offers more flexibility to encrypt the data or not optionally during the recording processes. In our system design, the function of encryption and non-encryption storage is switched by a random phase pattern and a uniform phase pattern. Based on a 90-degree geometry, the input patterns including the encryption and non-encryption storage are stored via angular multiplexing with reference plane waves at different incident angles. Image is encrypted optionally by sliding the ground glass into one of the recording waves or removing it away in each exposure. The ground glass is a key for encryption. Besides, it is also an important key available for authorized user to decrypt the encrypted information.

Gravitation from entanglement in holographic CFTs

Energy Technology Data Exchange (ETDEWEB)

Faulkner, Thomas [Institute for Advanced Study,Princeton, NJ 08540 (United States); Guica, Monica [Department of Physics and Astronomy, University of Pennsylvania,209 S. 33rd St., Philadelphia, PA 19104-6396 (United States); Hartman, Thomas [Kavli Institute for Theoretical Physics, University of California,Santa Barbara, CA 93106-4030 (United States); Myers, Robert C. [Perimeter Institute for Theoretical Physics,31 Caroline Street N., Waterloo, Ontario N2L 2Y5 (Canada); Raamsdonk, Mark Van [Department of Physics and Astronomy, University of British Columbia,6224 Agricultural Road, Vancouver, B.C. V6T 1W9 (Canada)

2014-03-11

Entanglement entropy obeys a ‘first law’, an exact quantum generalization of the ordinary first law of thermodynamics. In any CFT with a semiclassical holographic dual, this first law has an interpretation in the dual gravitational theory as a constraint on the spacetimes dual to CFT states. For small perturbations around the CFT vacuum state, we show that the set of such constraints for all ball-shaped spatial regions in the CFT is exactly equivalent to the requirement that the dual geometry satisfy the gravitational equations of motion, linearized about pure AdS. For theories with entanglement entropy computed by the Ryu-Takayanagi formula S=A/(4G{sub N}), we obtain the linearized Einstein equations. For theories in which the vacuum entanglement entropy for a ball is computed by more general Wald functionals, we obtain the linearized equations for the associated higher-curvature theories. Using the first law, we also derive the holographic dictionary for the stress tensor, given the holographic formula for entanglement entropy. This method provides a simple alternative to holographic renormalization for computing the stress tensor expectation value in arbitrary higher derivative gravitational theories.

Application Of Pulsed Laser Holography To Nondestructive Testing Of Aircraft Structures

Science.gov (United States)

Fagot, Hubert; Smigielski, Paul; Arnaud, Jean-Louis

1983-03-01

Subsequently to laboratory tests, experiments were conducted on an aircraft undergoing maintenance in order to assess the possible uses of holographic interferometry for non-destructive testing of large aircraft structures. A double ruby laser was used delivering two pulses with a duration of 20 ns each. The two pulses are separated by an arbitrary time interval At which is determined as a function of both the amplitude and frequency of the surface displacement. Shocks of the order of 100 mJ cause the structure under investigation to vibrate, the time interval At thereby ranging from 10 to 100 ps for a delay of a few ms after shock initiation. The method used is relatively insensitive to environmental disturbances. Although the laser delivers pulses of light of less than 100 mJ in energy, it is possible to visualize a field of 0.5 x1 m. Some results will be reported which have been obtained at the lower surface of an aerofoil, on a wheel well and on an air-brake. Finally a brief review will be made on the improvements envisaged on both the laser and the recording method in order to obtain an operational system for holographic non-destructive testing.

Pulsed neutron generator for mass flow measurement using the pulsed neutron activation technique

International Nuclear Information System (INIS)

Rochau, G.E.; Hornsby, D.R.; Mareda, J.F.; Riggan, W.C.

1980-01-01

A high-output, transportable neutron generator has been developed to measure mass flow velocities in reactor safety tests using the Pulsed Neutron Activation (PNA) Technique. The PNA generator produces >10 10 14 MeV D-T neutrons in a 1.2 millisecond pulse. The Millisecond Pulse (MSP) Neutron Tube, developed for this application, has an expected operational life of 1000 pulses, and it limits the generator pulse repetition rate to 12 pulses/minute. A semiconductor neutron detector is included in the generator package to monitor the neutron output. The control unit, which can be operated manually or remotely, also contains a digital display with a BCD output for the neutron monitor information. The digital logic of the unit controls the safety interlocks and rejects transient signals which could accidently fire the generator

The compact and inexpensive arrowhead setup for holographic interferometry

Energy Technology Data Exchange (ETDEWEB)

Ladera, Celso L; Donoso, Guillermo, E-mail: clladera@usb.v [Departamento de Fisica, Universidad Simon BolIvar, Apdo. 89000, Caracas 1086 (Venezuela, Bolivarian Republic of)

2011-07-15

Hologram recording and holographic interferometry are intrinsically sensitive to phase changes, and therefore both are easily perturbed by minuscule optical path perturbations. It is therefore very convenient to bank on holographic setups with a reduced number of optical components. Here we present a compact off-axis holographic setup that requires neither a collimator nor a beam-splitter, and whose layout is reminiscent of an arrowhead. We show that this inexpensive setup is a good alternative for the study and applications of scientific holography by measuring small displacements and deformations of a body. The arrowhead setup will be found particularly useful for holography and holographic interferometry experiments and projects in teaching laboratories.

Weak-interacting holographic QCD

International Nuclear Information System (INIS)

Gazit, D.; Yee, H.-U.

2008-06-01

We propose a simple prescription for including low-energy weak-interactions into the frame- work of holographic QCD, based on the standard AdS/CFT dictionary of double-trace deformations. As our proposal enables us to calculate various electro-weak observables involving strongly coupled QCD, it opens a new perspective on phenomenological applications of holographic QCD. We illustrate efficiency and usefulness of our method by performing a few exemplar calculations; neutron beta decay, charged pion weak decay, and meson-nucleon parity non-conserving (PNC) couplings. The idea is general enough to be implemented in both Sakai-Sugimoto as well as Hard/Soft Wall models. (author)

Holographic subregion complexity for singular surfaces

Energy Technology Data Exchange (ETDEWEB)

Bakhshaei, Elaheh [Isfahan University of Technology, Department of Physics, Isfahan (Iran, Islamic Republic of); Mollabashi, Ali [Institute for Research in Fundamental Sciences (IPM), School of Physics, Tehran (Iran, Islamic Republic of); Shirzad, Ahmad [Isfahan University of Technology, Department of Physics, Isfahan (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, Tehran (Iran, Islamic Republic of)

2017-10-15

Recently holographic prescriptions were proposed to compute the quantum complexity of a given state in the boundary theory. A specific proposal known as 'holographic subregion complexity' is supposed to calculate the complexity of a reduced density matrix corresponding to a static subregion. We study different families of singular subregions in the dual field theory and find the divergence structure and universal terms of holographic subregion complexity for these singular surfaces. We find that there are new universal terms, logarithmic in the UV cut-off, due to the singularities of a family of surfaces including a kink in (2 + 1) dimensions and cones in even dimensional field theories. We also find examples of new divergent terms such as squared logarithm and negative powers times the logarithm of the UV cut-off parameter. (orig.)

Wavelet processing and digital interferometric contrast to improve reconstructions from X-ray Gabor holograms.

Science.gov (United States)

Aguilar, Juan C; Misawa, Masaki; Matsuda, Kiyofumi; Suzuki, Yoshio; Takeuchi, Akihisa; Yasumoto, Masato

2018-05-01

In this work, the application of an undecimated wavelet transformation together with digital interferometric contrast to improve the resulting reconstructions in a digital hard X-ray Gabor holographic microscope is shown. Specifically, the starlet transform is used together with digital Zernike contrast. With this contrast, the results show that only a small set of scales from the hologram are, in effect, useful, and it is possible to enhance the details of the reconstruction.

Digital pulse-shape discrimination applied to an ultra-low-background gas-proportional counting system. First results

International Nuclear Information System (INIS)

Aalseth, C.E.; Day, A.R.; Fuller, E.S.; Hoppe, E.W.; Keillor, M.E.; Mace, E.K.; Myers, A.W.; Overman, C.T.; Panisko, M.E.; Seifert, A.

2013-01-01

A new ultra-low-background proportional counter design was recently developed at Pacific Northwest National Laboratory (PNNL). This design, along with an ultra-low-background counting system which provides passive and active shielding with radon exclusion, has been developed to complement a new shallow underground laboratory (∼30 m water-equivalent) constructed at PNNL. After these steps to mitigate dominant backgrounds (cosmic rays, external gamma-rays, radioactivity in materials), remaining background events do not exclusively arise from ionization of the proportional counter gas. Digital pulse-shape discrimination (PSD) is thus employed to further improve measurement sensitivity. In this work, a template shape is generated for each individual sample measurement of interest, a 'self-calibrating' template. Differences in event topology can also cause differences in pulse shape. In this work, the temporal region analyzed for each event is refined to maximize background discrimination while avoiding unwanted sensitivity to event topology. This digital PSD method is applied to sample and background data, and initial measurement results from a biofuel methane sample are presented in the context of low-background measurements currently being developed. (author)

Acoustic emission linear pulse holography

International Nuclear Information System (INIS)

Collins, H.D.; Busse, L.J.; Lemon, D.K.

1983-01-01

This paper describes the emission linear pulse holography which produces a chronological linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. A thirty two point sampling array is used to construct phase-only linear holograms of simulated acoustic emission sources on large metal plates. The concept behind the AE linear pulse holography is illustrated, and a block diagram of a data acquisition system to implement the concept is given. Array element spacing, synthetic frequency criteria, and lateral depth resolution are specified. A reference timing transducer positioned between the array and the inspection zone and which inititates the time-of-flight measurements is described. The results graphically illustrate the technique using a one-dimensional FFT computer algorithm (ie. linear backward wave) for an AE image reconstruction

Fissile material detection and control facility with pulsed neutron sources and digital data processing

International Nuclear Information System (INIS)

Romodanov, V.L.; Chernikova, D.N.; Afanasiev, V.V.

2010-01-01

Full text: In connection with possible nuclear terrorism, there is long-felt need of devices for effective control of radioactive and fissile materials in the key points of crossing the state borders (airports, seaports, etc.), as well as various customs check-points. In International Science and Technology Center Projects No. 596 and No. 2978, a new physical method and digital technology have been developed for the detection of fissile and radioactive materials in models of customs facilities with a graphite moderator, pulsed neutron source and digital processing of responses from scintillation PSD detectors. Detectability of fissile materials, even those shielded with various radiation-absorbing screens, has been shown. The use of digital processing of scintillation signals in this facility is a necessary element, as neutrons and photons are discriminated in the time dependence of fissile materials responses at such loads on the electronic channels that standard types of spectrometers are inapplicable. Digital processing of neutron and photon responses practically resolves the problem of dead time and allows implementing devices, in which various energy groups of neutrons exist for some time after a pulse of source neutrons. Thus, it is possible to detect fissile materials deliberately concealed with shields having a large cross-section of absorption of photons and thermal neutrons. Two models of detection and the control of fissile materials were advanced: 1. the model based on graphite neutrons moderator and PSD scintillators with digital technology of neutrons and photons responses separation; 2. the model based on plastic scintillators and detecting of time coincidences of fission particles by digital technology. Facilities that count time coincidences of neutrons and photons occurring in the fission of fissile materials can use an Am Li source of neutrons, e.g. that is the case with the AWCC system. The disadvantages of the facility are related to the issues

Modifications to holographic entanglement entropy in warped CFT

Energy Technology Data Exchange (ETDEWEB)

Song, Wei; Wen, Qiang; Xu, Jianfei [Yau Mathematical Sciences Center, Tsinghua University,Beijing 100084 (China)

2017-02-13

In https://www.doi.org/10.1103/PhysRevLett.117.011602 it was observed that asymptotic boundary conditions play an important role in the study of holographic entanglement beyond AdS/CFT. In particular, the Ryu-Takayanagi proposal must be modified for warped AdS{sub 3} (WAdS{sub 3}) with Dirichlet boundary conditions. In this paper, we consider AdS{sub 3} and WAdS{sub 3} with Dirichlet-Neumann boundary conditions. The conjectured holographic duals are warped conformal field theories (WCFTs), featuring a Virasoro-Kac-Moody algebra. We provide a holographic calculation of the entanglement entropy and Rényi entropy using AdS{sub 3}/WCFT and WAdS{sub 3}/WCFT dualities. Our bulk results are consistent with the WCFT results derived by Castro-Hofman-Iqbal using the Rindler method. Comparing with https://www.doi.org/10.1103/PhysRevLett.117.011602, we explicitly show that the holographic entanglement entropy is indeed affected by boundary conditions. Both results differ from the Ryu-Takayanagi proposal, indicating new relations between spacetime geometry and quantum entanglement for holographic dualities beyond AdS/CFT.

Holographic grating relaxation technique for soft matter science

Energy Technology Data Exchange (ETDEWEB)

Lesnichii, Vasilii, E-mail: vasilii.lesnichii@physchem.uni-freiburg.de [Institute of Physical Chemistry, Albertstraße 21, Institute of Macromolecular Chemistry, Stefan-Meier-Str. 31, Albert-Ludwigs Universität, Freiburg im Breisgau 79104 (Germany); ITMO University, Kronverksky prospekt 49, Saint-Petersburg 197101 (Russian Federation); Kiessling, Andy [Institute of Physical Chemistry, Albertstraße 21, Institute of Macromolecular Chemistry, Stefan-Meier-Str. 31, Albert-Ludwigs Universität, Freiburg im Breisgau 79104 (Germany); Current address: Illinois Institute of Technology, 10 West 33rd Street, Chicago,IL60616 (United States); Bartsch, Eckhard [Institute of Physical Chemistry, Albertstraße 21, Institute of Macromolecular Chemistry, Stefan-Meier-Str. 31, Albert-Ludwigs Universität, Freiburg im Breisgau 79104 (Germany); Veniaminov, Andrey, E-mail: veniaminov@phoi.ifmo.ru [ITMO University, Kronverksky prospekt 49, Saint-Petersburg 197101 (Russian Federation)

2016-06-17

The holographic grating relaxation technique also known as forced Rayleigh scattering consists basically in writing a holographic grating in the specimen of interest and monitoring its diffraction efficiency as a function of time, from which valuable information on mass or heat transfer and photoinduced transformations can be extracted. In a more detailed view, the shape of the relaxation curve and the relaxation rate as a function of the grating period were found to be affected by the architecture of diffusing species (molecular probes) that constitute the grating, as well as that of the environment they diffuse in, thus making it possible to access and study spatial heterogeneity of materials and different modes of e.g., polymer motion. Minimum displacements and spatial domains approachable by the technique are in nanometer range, well below spatial periods of holographic gratings. In the present paper, several cases of holographic relaxation in heterogeneous media and complex motions are exemplified. Nano- to micro-structures or inhomogeneities comparable in spatial scale with holographic gratings manifest themselves in relaxation experiments via non-exponential decay (stepwise or stretched), spatial-period-dependent apparent diffusion coefficient, or unusual dependence of diffusion coefficient on molecular volume of diffusing probes.

A holographic perspective on phonons and pseudo-phonons

Energy Technology Data Exchange (ETDEWEB)

Amoretti, Andrea [Institute of Theoretical Physics and Astrophysics, University of Würzburg,97074 Würzburg (Germany); Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Areán, Daniel [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, D-80805, Munich (Germany); Argurio, Riccardo [Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Musso, Daniele [Departamento de Física de Partículas, Universidade de Santiago de Compostelaand Instituto Galego de Física de Altas Enerxías (IGFAE),E-15782, Santiago de Compostela (Spain); Zayas, Leopoldo A. Pando [Michigan Center for Theoretical Physics, Department of Physics, University of Michigan,Ann Arbor, MI 48109 (United States)

2017-05-10

We analyze the concomitant spontaneous breaking of translation and conformal symmetries by introducing in a CFT a complex scalar operator that acquires a spatially dependent expectation value. The model, inspired by the holographic Q-lattice, provides a privileged setup to study the emergence of phonons from a spontaneous translational symmetry breaking in a conformal field theory and offers valuable hints for the treatment of phonons in QFT at large. We first analyze the Ward identity structure by means of standard QFT techniques, considering both spontaneous and explicit symmetry breaking. Next, by implementing holographic renormalization, we show that the same set of Ward identities holds in the holographic Q-lattice. Eventually, relying on the holographic and QFT results, we study the correlators realizing the symmetry breaking pattern and how they encode information about the low-energy spectrum.

Holographic interferometric and correlation-based laser speckle metrology for 3D deformations in dentistry

Science.gov (United States)

Dekiff, Markus; Kemper, Björn; Kröger, Elke; Denz, Cornelia; Dirksen, Dieter

2017-03-01

The mechanical loading of dental restorations and hard tissue is often investigated numerically. For validation and optimization of such simulations, comparisons with measured deformations are essential. We combine digital holographic interferometry and digital speckle photography for the determination of microscopic deformations with a photogrammetric method that is based on digital image correlation of a projected laser speckle pattern. This multimodal workstation allows the simultaneous acquisition of the specimen's macroscopic 3D shape and thus a quantitative comparison of measured deformations with simulation data. In order to demonstrate the feasibility of our system, two applications are presented: the quantitative determination of (1) the deformation of a mandible model due to mechanical loading of an inserted dental implant and of (2) the deformation of a (dental) bridge model under mechanical loading. The results were compared with data from finite element analyses of the investigated applications. The experimental results showed close agreement with those of the simulations.

Review of Random Phase Encoding in Volume Holographic Storage

Directory of Open Access Journals (Sweden)

Wei-Chia Su

2012-09-01

Full Text Available Random phase encoding is a unique technique for volume hologram which can be applied to various applications such as holographic multiplexing storage, image encryption, and optical sensing. In this review article, we first review and discuss diffraction selectivity of random phase encoding in volume holograms, which is the most important parameter related to multiplexing capacity of volume holographic storage. We then review an image encryption system based on random phase encoding. The alignment of phase key for decryption of the encoded image stored in holographic memory is analyzed and discussed. In the latter part of the review, an all-optical sensing system implemented by random phase encoding and holographic interconnection is presented.

Holographic entropy inequalities and gapped phases of matter

Energy Technology Data Exchange (ETDEWEB)

Bao, Ning [Institute for Quantum Information and Matter, California Institute of Technology,Pasadena, CA 91125 (United States); Walter Burke Institute for Theoretical Physics, California Institute of Technology,Pasadena, CA 91125 (United States); Cao, ChunJun [Walter Burke Institute for Theoretical Physics, California Institute of Technology,Pasadena, CA 91125 (United States); Walter, Michael [Stanford Institute for Theoretical Physics,Stanford University, Stanford, CA 94305 (United States); Wang, Zitao [Institute for Quantum Information and Matter, California Institute of Technology,Pasadena, CA 91125 (United States); Walter Burke Institute for Theoretical Physics, California Institute of Technology,Pasadena, CA 91125 (United States)

2015-09-29

We extend our studies of holographic entropy inequalities to gapped phases of matter. For any number of regions, we determine the linear entropy inequalities satisfied by systems in which the entanglement entropy satisfies an exact area law. In particular, we find that all holographic entropy inequalities are valid in such systems. In gapped systems with topological order, the “cyclic inequalities” derived recently for the holographic entanglement entropy generalize the Kitaev-Preskill formula for the topological entanglement entropy. Finally, we propose a candidate linear inequality for general 4-party quantum states.

Holographic entropy inequalities and gapped phases of matter

International Nuclear Information System (INIS)

Bao, Ning; Cao, ChunJun; Walter, Michael; Wang, Zitao

2015-01-01

We extend our studies of holographic entropy inequalities to gapped phases of matter. For any number of regions, we determine the linear entropy inequalities satisfied by systems in which the entanglement entropy satisfies an exact area law. In particular, we find that all holographic entropy inequalities are valid in such systems. In gapped systems with topological order, the “cyclic inequalities” derived recently for the holographic entanglement entropy generalize the Kitaev-Preskill formula for the topological entanglement entropy. Finally, we propose a candidate linear inequality for general 4-party quantum states.

Pump-induced optical distortions in disk amplifier modules: holographic and interferometric measurements

International Nuclear Information System (INIS)

Linford, G.J.; Chau, H.H.; Glaze, J.A.; Layne, C.B.; Rainer, F.

1975-01-01

Interferometric measurements have been made of the optical distortions induced in laser disk amplifiers during the flashlamp pumping pulse. Both conventional interferometric methods and the techniques of double exposure holographic interferometry were used to identify four major sources of pump-induced optical distortions: subsonic intrusion of hot gas (traced to leakage of atmospheric oxygen into the amplifier), microexplosions of dust particles, thermally induced optical distortions in the glass disks, and gaseous optical distortion effects caused by turbulent flow of the purging nitrogen gas supply used within the laser amplifier head. Methods for reducing or eliminating the effects of each of these optical distortions are described

Generalized exact holographic mapping with wavelets

Science.gov (United States)

Lee, Ching Hua

2017-12-01

The idea of renormalization and scale invariance is pervasive across disciplines. It has not only drawn numerous surprising connections between physical systems under the guise of holographic duality, but has also inspired the development of wavelet theory now widely used in signal processing. Synergizing on these two developments, we describe in this paper a generalized exact holographic mapping that maps a generic N -dimensional lattice system to a (N +1 )-dimensional holographic dual, with the emergent dimension representing scale. In previous works, this was achieved via the iterations of the simplest of all unitary mappings, the Haar mapping, which fails to preserve the form of most Hamiltonians. By taking advantage of the full generality of biorthogonal wavelets, our new generalized holographic mapping framework is able to preserve the form of a large class of lattice Hamiltonians. By explicitly separating features that are fundamentally associated with the physical system from those that are basis specific, we also obtain a clearer understanding of how the resultant bulk geometry arises. For instance, the number of nonvanishing moments of the high-pass wavelet filter is revealed to be proportional to the radius of the dual anti-de Sitter space geometry. We conclude by proposing modifications to the mapping for systems with generic Fermi pockets.

A holographic model for black hole complementarity

Energy Technology Data Exchange (ETDEWEB)

Lowe, David A. [Physics Department, Brown University,Providence, RI 02912 (United States); Thorlacius, Larus [University of Iceland, Science Institute,Dunhaga 3, IS-107, Reykjavik (Iceland); The Oskar Klein Centre for Cosmoparticle Physics,Department of Physics, Stockholm University,AlbaNova University Centre, 10691 Stockholm (Sweden)

2016-12-07

We explore a version of black hole complementarity, where an approximate semiclassical effective field theory for interior infalling degrees of freedom emerges holographically from an exact evolution of exterior degrees of freedom. The infalling degrees of freedom have a complementary description in terms of outgoing Hawking radiation and must eventually decohere with respect to the exterior Hamiltonian, leading to a breakdown of the semiclassical description for an infaller. Trace distance is used to quantify the difference between the complementary time evolutions, and to define a decoherence time. We propose a dictionary where the evolution with respect to the bulk effective Hamiltonian corresponds to mean field evolution in the holographic theory. In a particular model for the holographic theory, which exhibits fast scrambling, the decoherence time coincides with the scrambling time. The results support the hypothesis that decoherence of the infalling holographic state and disruptive bulk effects near the curvature singularity are complementary descriptions of the same physics, which is an important step toward resolving the black hole information paradox.

Holographic Aquaculture

Science.gov (United States)

Ian, Richard; King, Elisabeth

1988-01-01

Proposed is an exploratory study to verify the feasibility of an inexpensive micro-climate control system for both marine and freshwater pond and tank aquaculture, offering good control over water temperature, incident light flux, and bandwidth, combined with good energy efficiency. The proposed control system utilizes some familiar components of passive solar design, together with a new holographic glazing system which is currently being developed by, and proprietary to Advanced Environmental Research Group (AERG). The use of solar algae ponds and tanks to warm and purify water for fish and attached macroscopic marine algae culture is an ancient and effective technique, but limited seasonally and geographically by the availability of sunlight. Holographic Diffracting Structures (HDSs) can be made which passively track, accept and/or reject sunlight from a wide range of altitude and azimuth angles, and redirect and distribute light energy as desired (either directly or indirectly over water surface in an enclosed, insulated structure), effectively increasing insolation values by accepting sunlight which would not otherwise enter the structure.

Deuteron transverse densities in holographic QCD

Energy Technology Data Exchange (ETDEWEB)

Mondal, Chandan [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); Indian Institute of Technology Kanpur, Department of Physics, Kanpur (India); Chakrabarti, Dipankar [Indian Institute of Technology Kanpur, Department of Physics, Kanpur (India); Zhao, Xingbo [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China)

2017-05-15

We investigate the transverse charge density in the longitudinally as well as transversely polarized deuteron using the recent empirical description of the deuteron electromagnetic form factors in the framework of holographic QCD. The predictions of the holographic QCD are compared with the results of a standard phenomenological parameterization. In addition, we evaluate GPDs and the gravitational form factors for the deuteron. The longitudinal momentum densities are also investigated in the transverse plane. (orig.)

Holographic interferometry in construction analysis

Energy Technology Data Exchange (ETDEWEB)

Hartikainen, T.

1995-12-31

In this work techniques for visualizing phase and opaque objects by ruby laser interferometry are introduced. A leakage flow as a phase object is studied by holographic interferometry and the intensity distribution of the interferograms presenting the leakage flow are computer-simulated. A qualitative and quantitative analysis of the leakage flow is made. The analysis is based on the experimental and theoretical results presented in this work. The holographic setup and the double pass method for visualizing leakage flow are explained. A vibrating iron plate is the opaque object. Transient impact waves are generated by a pistol bullet on the iron plate and visualized by holographic interferometry. An apparatus with the capability of detecting and calculating the delays necessary for laser triggering is introduced. A time series of interferograms presenting elastic wave formation in an iron plate is shown. A computer-simulation of the intensity distributions of these interferograms is made. An analysis based on the computer-simulation and the experimental data of the transient elastic wave is carried out and the results are presented. (author)

A pulse-shape discrimination method for improving Gamma-ray spectrometry based on a new digital shaping filter

Science.gov (United States)

Qin, Zhang-jian; Chen, Chuan; Luo, Jun-song; Xie, Xing-hong; Ge, Liang-quan; Wu, Qi-fan

2018-04-01

It is a usual practice for improving spectrum quality by the mean of designing a good shaping filter to improve signal-noise ratio in development of nuclear spectroscopy. Another method is proposed in the paper based on discriminating pulse-shape and discarding the bad pulse whose shape is distorted as a result of abnormal noise, unusual ballistic deficit or bad pulse pile-up. An Exponentially Decaying Pulse (EDP) generated in nuclear particle detectors can be transformed into a Mexican Hat Wavelet Pulse (MHWP) and the derivation process of the transform is given. After the transform is performed, the baseline drift is removed in the new MHWP. Moreover, the MHWP-shape can be discriminated with the three parameters: the time difference between the two minima of the MHWP, and the two ratios which are from the amplitude of the two minima respectively divided by the amplitude of the maximum in the MHWP. A new type of nuclear spectroscopy was implemented based on the new digital shaping filter and the Gamma-ray spectra were acquired with a variety of pulse-shape discrimination levels. It had manifested that the energy resolution and the peak-Compton ratio were both improved after the pulse-shape discrimination method was used.

Amplification and focusing of a picosecond chirped pulse to 20TW and 5x1017W/cm2

International Nuclear Information System (INIS)

Sauteret, C.; Husson, D.; Rouyer, C.; Seznec, S.; Gary, S.

1991-01-01

Pulses of 20 TW power have been generated at 1064 nm using the Chirped Pulse Amplification technique coupled to a 90 mm output aperture powerful Nd:silicate glass amplification line. This system delivers 60 J in a chirped pulse of 600 ps duration with a capacity of maintaining 3.5 nm output bandwidth. These chirped pulses have been compressed to 1.2 ps with an energy of 24J using large holographic diffraction gratings. After presenting the results we discuss the expected applications in atomic and plasma physics

Phase alteration compensation in reflection digital holography

International Nuclear Information System (INIS)

Rincon, O; Amezquita, R; Monroy, F

2011-01-01

The phase maps obtained from digital holographic microscopy techniques carry information about the axial lengths of the object under study. Additionally, these phase maps have information of tilt and curvatures with origin in the off-axis geometry and the magnification lenses system, respectively. Only a complete compensation of these extra phases allows a correct interpretation of the phase information. In this article a numerical strategy to compensate for these alterations is designed, using a phase mask located in different planes. This strategy is applied in the measurement of a phase steps plate using a digital holography setup.

Flow visualization and aero-optics in simulated environments; Proceedings of the Meeting, Orlando, FL, May 21, 22, 1987

International Nuclear Information System (INIS)

Bentley, H.T. III.

1987-01-01

The present conference on high speed aerooptics facilities, aerodynamic holography, and photooptical techniques gives attention to the prediction of image degradation through a turbulent medium, wind tunnel studies of optical beam degradation through heterogeneous aerodynamic flows, wavelength effects on images formed through turbulence, holographic visualizations of hypersonic flow viscous interactions, holographic interferometry for gas flow pattern studies, and a holographic flow field analysis of Spacelab-3 crystal growth experiments. Also discussed are the interferometric reconstruction of continuous flow fields, the flow visualization of turbine film cooling flows, the use of the phosphor technique for remote thermometry in a combustor, pulsed laser cinematography of deflagration, and a digital image sequence analysis for optical flow computation in flame propagation visualization

Development of integral holographic motion pictures

Science.gov (United States)

Alexander, P.

1995-02-01

In 1985 Anne-Marie Christakis selected me to make the first pulse holographic feature-fiction movie. Up to that time, the process had only been used for laboratory tests. The running time for the movie was to be 1 minute 20 seconds. Apparently quite long compared with previous tests, but an extremely short time in which to tell a story. I chose the characters of Beauty and the Beast. A lot of time was spent in preparatory work: triple distilling the scenario to get it down to 80 seconds; paintings and masks, and I extracted the music from a suite I had already written in medieval style. The movie was made in 1986 in the laboratory of Professeur Smigielsky, which was located in the Franco-German Defense Research Establishment, at St. Louis in France. Prof. Smigielsky's staff operated all the equipment and Anne-Marie Christakis coordinated everything, as she had done throughout the project. As soon as we arrived at the laboratory, we were told not to look beyond a certain angle towards the laser, otherwise we could be blinded for life. With all that dangerous power however, it was only possible to illuminate a volume for the set of half a meter wide by half a meter deep by one third of a meter high. Such a set gives real meaning to the expression `cramp one's style.' The layout used was, in principle, the same as for making a simple hologram. A pulsed YAG laser was used and each pulse was synchronized with a new frame to be exposed in the camera. When the movie was finished, it was not very bright, and one had to look through a small aperture to view it.

Silver-halide sensitized gelatin (SHSG) processing method for pulse holograms recorded on VRP plates

Science.gov (United States)

Evstigneeva, Maria K.; Drozdova, Olga V.; Mikhailov, Viktor N.

2002-06-01

One of the most important area of holograph applications is display holography. In case of pulse recording the requirement for vibration stability is easier than compared to CW exposure. At the same time it is widely known that the behavior of sliver-halide holographic materials strongly depends on the exposure duration. In particular the exposure sensitivity drastically decreases under nanosecond pulse duration. One of the effective ways of the diffraction efficiency improvement is SHSG processing method. This processing scheme is based on high modulation of refractive index due to microvoids appearance inside emulsion layer. It should be mentioned that the SHSG method was used earlier only in the cases when the holograms were recorded by use of CW lasers. This work is devoted to the investigation of SHSG method for pulse hologram recording on VRP plates. We used a pulsed YLF:Nd laser with pulse duration of 25 nanoseconds and wavelength of 527 nm. Both transmission and reflection holograms were recorded. The different kinds of bleaching as well as developing solutions were investigated. Our final processing scheme includes the following stages: 1) development in non-tanning solution, 2) rehalogenating bleach, 3) intermediate alcohol drying, 4) uniform second exposure, 5) second development in diluted developer, 6) reverse bleaching, 7) fixing and 8) gradient drying in isopropyl alcohol. Diffraction efficiency of transmission holograms was of about 60 percent and reflection mirror holograms was of about 45 percent. Thus we have demonstrated the SHSG processing scheme for producing effective holograms on VRP plates under pulse exposure.

Visualizing Breath using Digital Holography

Science.gov (United States)

Hobson, P. R.; Reid, I. D.; Wilton, J. B.

2013-02-01

Artist Jayne Wilton and physicists Peter Hobson and Ivan Reid of Brunel University are collaborating at Brunel University on a project which aims to use a range of techniques to make visible the normally invisible dynamics of the breath and the verbal and non-verbal communication it facilitates. The breath is a source of a wide range of chemical, auditory and physical exchanges with the direct environment. Digital Holography is being investigated to enable a visually stimulating articulation of the physical trajectory of the breath as it leaves the mouth. Initial findings of this research are presented. Real time digital hologram replay allows the audience to move through holographs of breath-born particles.

Holographic duality in condensed matter physics

CERN Document Server

Zaanen, Jan; Sun, Ya-Wen; Schalm, Koenraad

2015-01-01

A pioneering treatise presenting how the new mathematical techniques of holographic duality unify seemingly unrelated fields of physics. This innovative development morphs quantum field theory, general relativity and the renormalisation group into a single computational framework and this book is the first to bring together a wide range of research in this rapidly developing field. Set within the context of condensed matter physics and using boxes highlighting the specific techniques required, it examines the holographic description of thermal properties of matter, Fermi liquids and superconductors, and hitherto unknown forms of macroscopically entangled quantum matter in terms of general relativity, stars and black holes. Showing that holographic duality can succeed where classic mathematical approaches fail, this text provides a thorough overview of this major breakthrough at the heart of modern physics. The inclusion of extensive introductory material using non-technical language and online Mathematica not...

Surface relief and refractive index gratings patterned in chalcogenide glasses and studied by off-axis digital holography.

Science.gov (United States)

Cazac, V; Meshalkin, A; Achimova, E; Abashkin, V; Katkovnik, V; Shevkunov, I; Claus, D; Pedrini, G

2018-01-20

Surface relief gratings and refractive index gratings are formed by direct holographic recording in amorphous chalcogenide nanomultilayer structures As 2 S 3 -Se and thin films As 2 S 3 . The evolution of the grating parameters, such as the modulation of refractive index and relief depth in dependence of the holographic exposure, is investigated. Off-axis digital holographic microscopy is applied for the measurement of the photoinduced phase gratings. For the high-accuracy reconstruction of the wavefront (amplitude and phase) transmitted by the fabricated gratings, we used a computational technique based on the sparse modeling of phase and amplitude. Both topography and refractive index maps of recorded gratings are revealed. Their separated contribution in diffraction efficiency is estimated.

Measurements of the Characteristics of Transparent Material Using Digital Holography

Directory of Open Access Journals (Sweden)

Ding Yu

2013-01-01

Full Text Available Digital holography is applied to measure the characteristics of transparent material. A digital hologram recording system to measure the surface of transparent material was established, and the digital holograms of transparent object were obtained in high quality. For postprocessing of hologram, the least-squares phase unwrapping algorithm was used in phase unwrapping, and the phase reconstruction image of transparent object was obtained. The information of material surfaces was measured and the characteristic was presented in 3D visualization. The validation experiment was conducted by NanoMap 500LS system; the results of validation experiment are well satisfied with the measurement by digital holography, which proved the feasibility of digital holographic technology as a good measurement tool for transparent material.

Entropy-Corrected Holographic Dark Energy

International Nuclear Information System (INIS)

Wei Hao

2009-01-01

The holographic dark energy (HDE) is now an interesting candidate of dark energy, which has been studied extensively in the literature. In the derivation of HDE, the black hole entropy plays an important role. In fact, the entropy-area relation can be modified due to loop quantum gravity or other reasons. With the modified entropy-area relation, we propose the so-called 'entropy-corrected holographic dark energy' (ECHDE) in the present work. We consider many aspects of ECHDE and find some interesting results. In addition, we briefly consider the so-called 'entropy-corrected agegraphic dark energy' (ECADE). (geophysics, astronomy, and astrophysics)

High-throughput characterization of stresses in thin film materials libraries using Si cantilever array wafers and digital holographic microscopy.

Science.gov (United States)

Lai, Y W; Hamann, S; Ehmann, M; Ludwig, A

2011-06-01

We report the development of an advanced high-throughput stress characterization method for thin film materials libraries sputter-deposited on micro-machined cantilever arrays consisting of around 1500 cantilevers on 4-inch silicon-on-insulator wafers. A low-cost custom-designed digital holographic microscope (DHM) is employed to simultaneously monitor the thin film thickness, the surface topography and the curvature of each of the cantilevers before and after deposition. The variation in stress state across the thin film materials library is then calculated by Stoney's equation based on the obtained radii of curvature of the cantilevers and film thicknesses. DHM with nanometer-scale out-of-plane resolution allows stress measurements in a wide range, at least from several MPa to several GPa. By using an automatic x-y translation stage, the local stresses within a 4-inch materials library are mapped with high accuracy within 10 min. The speed of measurement is greatly improved compared with the prior laser scanning approach that needs more than an hour of measuring time. A high-throughput stress measurement of an as-deposited Fe-Pd-W materials library was evaluated for demonstration. The fast characterization method is expected to accelerate the development of (functional) thin films, e.g., (magnetic) shape memory materials, whose functionality is greatly stress dependent. © 2011 American Institute of Physics

X-ray Fourier-transform holographic microscope

International Nuclear Information System (INIS)

Haddad, W.S.; Cullen, D.; Solem, J.C.; Boyer, K.; Rhodes, C.K.

1988-01-01

The properties of an x-ray Fourier-transform holographic instrument suitable for imaging hydrated biological samples are described. Recent advances in coherent x-ray source technology are making diffraction-limited holograms of microscopic structures, with corresponding high spatial resolution, a reality. A high priority application of snapshot x-ray holography is the study of microscopic biological structures in the hydrated living state. X-rays offer both high resolution and high contrast for important structures within living organisms, thereby rendering unnecessary the staining of specimens, essential for optical and electron microscopy. If the wavelength is properly chosen. Furthermore, the snapshot feature, arising from picosecond or subpicosecond exposure times, eliminates blurring occurring from either thermal heating or normal biological activity of the sample. Finally, with sufficiently high photon fluxes, such as those available from x-ray lasers, the x-ray snapshot can be accomplished with a single pulse, thereby yielding complete three-dimensional information on a sample having normal biological integrity at the moment of exposure. 10 refs., 6 figs

Phases of kinky holographic nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Elliot-Ripley, Matthew; Sutcliffe, Paul; Zamaklar, Marija [Department of Mathematical Sciences, Durham University,South Road, Durham (United Kingdom)

2016-10-17

Holographic QCD at finite baryon number density and zero temperature is studied within the five-dimensional Sakai-Sugimoto model. We introduce a new approximation that models a smeared crystal of solitonic baryons by assuming spatial homogeneity to obtain an effective kink theory in the holographic direction. The kink theory correctly reproduces a first order phase transition to lightly bound nuclear matter. As the density is further increased the kink splits into a pair of half-kink constituents, providing a concrete realization of the previously suggested dyonic salt phase, where the bulk soliton splits into constituents at high density. The kink model also captures the phenomenon of baryonic popcorn, in which a first order phase transition generates an additional soliton layer in the holographic direction. We find that this popcorn transition takes place at a density below the dyonic salt phase, making the latter energetically unfavourable. However, the kink model predicts only one pop, rather than the sequence of pops suggested by previous approximations. In the kink model the two layers produced by the single pop form the surface of a soliton bag that increases in size as the baryon chemical potential is increased. The interior of the bag is filled with abelian electric potential and the instanton charge density is localized on the surface of the bag. The soliton bag may provide a holographic description of a quarkyonic phase.

Pattern recognition with magnonic holographic memory device

International Nuclear Information System (INIS)

Kozhevnikov, A.; Dudko, G.; Filimonov, Y.; Gertz, F.; Khitun, A.

2015-01-01

In this work, we present experimental data demonstrating the possibility of using magnonic holographic devices for pattern recognition. The prototype eight-terminal device consists of a magnetic matrix with micro-antennas placed on the periphery of the matrix to excite and detect spin waves. The principle of operation is based on the effect of spin wave interference, which is similar to the operation of optical holographic devices. Input information is encoded in the phases of the spin waves generated on the edges of the magnonic matrix, while the output corresponds to the amplitude of the inductive voltage produced by the interfering spin waves on the other side of the matrix. The level of the output voltage depends on the combination of the input phases as well as on the internal structure of the magnonic matrix. Experimental data collected for several magnonic matrixes show the unique output signatures in which maxima and minima correspond to specific input phase patterns. Potentially, magnonic holographic devices may provide a higher storage density compare to optical counterparts due to a shorter wavelength and compatibility with conventional electronic devices. The challenges and shortcoming of the magnonic holographic devices are also discussed

Reflection mode holographic recording in methylene blue-sensitized ...

Indian Academy of Sciences (India)

2014-02-13

Feb 13, 2014 ... Thus, in recent years much attention has been centred on ... as bit-format holographic data storage [7] and visual indication of ... The characteristics of holographic recording material have great effects on the success- ... widely for display applications, for cover pages of books, magazines, pop art display,.

Digital holography and wavefront sensing principles, techniques and applications

CERN Document Server

Schnars, Ulf; Watson, John; Jüptner, Werner

2015-01-01

This book presents a self-contained treatment of the principles and major applications of digital hologram recording and numerical reconstruction (Digital Holography). This second edition has been significantly revised and enlarged. The authors have extended the chapter on Digital Holographic Microscopy to incorporate new sections on particle sizing, particle image velocimetry and underwater holography. A new chapter now deals comprehensively and extensively with computational wave field sensing. These techniques represent a fascinating alternative to standard interferometry and Digital Holography. They enable wave field sensing without the requirement of a particular reference wave, thus allowing the use of low brilliance light sources and even liquid-crystal displays (LCD) for interferometric applications.              

Predation by the Dwarf Seahorse on Copepods: Quantifying Motion and Flows Using 3D High Speed Digital Holographic Cinematography - When Seahorses Attack!

Science.gov (United States)

Gemmell, Brad; Sheng, Jian; Buskey, Ed

2008-11-01

Copepods are an important planktonic food source for most of the world's fish species. This high predation pressure has led copepods to evolve an extremely effective escape response, with reaction times to hydrodynamic disturbances of less than 4 ms and escape speeds of over 500 body lengths per second. Using 3D high speed digital holographic cinematography (up to 2000 frames per second) we elucidate the role of entrainment flow fields generated by a natural visual predator, the dwarf seahorse (Hippocampus zosterae) during attacks on its prey, Acartia tonsa. Using phytoplankton as a tracer, we recorded and reconstructed 3D flow fields around the head of the seahorse and its prey during both successful and unsuccessful attacks to better understand how some attacks lead to capture with little or no detection from the copepod while others result in failed attacks. Attacks start with a slow approach to minimize the hydro-mechanical disturbance which is used by copepods to detect the approach of a potential predator. Successful attacks result in the seahorse using its pipette-like mouth to create suction faster than the copepod's response latency. As these characteristic scales of entrainment increase, a successful escape becomes more likely.

Collapse and revival in holographic quenches

International Nuclear Information System (INIS)

Silva, Emilia da; Lopez, Esperanza; Mas, Javier; Serantes, Alexandre

2015-01-01

We study holographic models related to global quantum quenches in finite size systems. The holographic set up describes naturally a CFT, which we consider on a circle and a sphere. The enhanced symmetry of the conformal group on the circle motivates us to compare the evolution in both cases. Depending on the initial conditions, the dual geometry exhibits oscillations that we holographically interpret as revivals of the initial field theory state. On the sphere, this only happens when the energy density created by the quench is small compared to the system size. However on the circle considerably larger energy densities are compatible with revivals. Two different timescales emerge in this latter case. A collapse time, when the system appears to have dephased, and the revival time, when after rephasing the initial state is partially recovered. The ratio of these two times depends upon the initial conditions in a similar way to what is observed in some experimental setups exhibiting collapse and revivals.

Holographic complexity and noncommutative gauge theory

Science.gov (United States)

Couch, Josiah; Eccles, Stefan; Fischler, Willy; Xiao, Ming-Lei

2018-03-01

We study the holographic complexity of noncommutative field theories. The four-dimensional N=4 noncommutative super Yang-Mills theory with Moyal algebra along two of the spatial directions has a well known holographic dual as a type IIB supergravity theory with a stack of D3 branes and non-trivial NS-NS B fields. We start from this example and find that the late time holographic complexity growth rate, based on the "complexity equals action" conjecture, experiences an enhancement when the non-commutativity is turned on. This enhancement saturates a new limit which is exactly 1/4 larger than the commutative value. We then attempt to give a quantum mechanics explanation of the enhancement. Finite time behavior of the complexity growth rate is also studied. Inspired by the non-trivial result, we move on to more general setup in string theory where we have a stack of D p branes and also turn on the B field. Multiple noncommutative directions are considered in higher p cases.

Hiding a Covert Digital Image by Assembling the RSA Encryption Method and the Binary Encoding Method

OpenAIRE

Kuang Tsan Lin; Sheng Lih Yeh

2014-01-01

The Rivest-Shamir-Adleman (RSA) encryption method and the binary encoding method are assembled to form a hybrid hiding method to hide a covert digital image into a dot-matrix holographic image. First, the RSA encryption method is used to transform the covert image to form a RSA encryption data string. Then, all the elements of the RSA encryption data string are transferred into binary data. Finally, the binary data are encoded into the dot-matrix holographic image. The pixels of the dot-matri...

Hiding a Covert Digital Image by Assembling the RSA Encryption Method and the Binary Encoding Method

Directory of Open Access Journals (Sweden)

Kuang Tsan Lin

2014-01-01

Full Text Available The Rivest-Shamir-Adleman (RSA encryption method and the binary encoding method are assembled to form a hybrid hiding method to hide a covert digital image into a dot-matrix holographic image. First, the RSA encryption method is used to transform the covert image to form a RSA encryption data string. Then, all the elements of the RSA encryption data string are transferred into binary data. Finally, the binary data are encoded into the dot-matrix holographic image. The pixels of the dot-matrix holographic image contain seven groups of codes used for reconstructing the covert image. The seven groups of codes are identification codes, covert-image dimension codes, covert-image graylevel codes, pre-RSA bit number codes, RSA key codes, post-RSA bit number codes, and information codes. The reconstructed covert image derived from the dot-matrix holographic image and the original covert image are exactly the same.

Holographic renormalization group and cosmology in theories with quasilocalized gravity

International Nuclear Information System (INIS)

Csaki, Csaba; Erlich, Joshua; Hollowood, Timothy J.; Terning, John

2001-01-01

We study the long distance behavior of brane theories with quasilocalized gravity. The five-dimensional (5D) effective theory at large scales follows from a holographic renormalization group flow. As intuitively expected, the graviton is effectively four dimensional at intermediate scales and becomes five dimensional at large scales. However, in the holographic effective theory the essentially 4D radion dominates at long distances and gives rise to scalar antigravity. The holographic description shows that at large distances the Gregory-Rubakov-Sibiryakov (GRS) model is equivalent to the model recently proposed by Dvali, Gabadadze, and Porrati (DGP), where a tensionless brane is embedded into 5D Minkowski space, with an additional induced 4D Einstein-Hilbert term on the brane. In the holographic description the radion of the GRS model is automatically localized on the tensionless brane, and provides the ghostlike field necessary to cancel the extra graviton polarization of the DGP model. Thus, there is a holographic duality between these theories. This analysis provides physical insight into how the GRS model works at intermediate scales; in particular it sheds light on the size of the width of the graviton resonance, and also demonstrates how the holographic renormalization group can be used as a practical tool for calculations

A method to reduce the suppression of relevant pulses in pulse weight discriminators

International Nuclear Information System (INIS)

Schwartz, P.

1975-01-01

The pulse height analyzer is used, for instance, with proportional counters. Pulses are broken down into amplitude ranges in accordance with their maximum amplitudes. In pulse height analyzers with real time analog-digital conversion only one deadtime is needed for the respective range selected. For this purpose, all discriminator thresholds of the amplitude stores connected parallel are actuated as an input pulse arrives. The leading edges of the discriminator signals set the amplitude range flip-flop. Only the flip-flop circuit of the maximum amplitude range reached remains set whilst all the others are erased. The trailing edge of the discriminator signals actuates the evaluation of the information stored by the flip-flop circuit selected. It triggers a pulse extender and resets the flip-flop selected. Therefore, only the amplitude range selected needs a deadtime. The pulse extender in addition reduces the processing time of the analyzer by the output pulse length. The characteristic used for the trailing edge is the backward count of the real time analog-digital converter. (DG/RF) [de

Holographic Two-Photon Induced Photopolymerization

Data.gov (United States)

Federal Laboratory Consortium — Holographic two-photon-induced photopolymerization (HTPIP) offers distinct advantages over conventional one-photon-induced photopolymerization and current techniques...

Three-directional motion-compensation mask-based novel look-up table on graphics processing units for video-rate generation of digital holographic videos of three-dimensional scenes.

Science.gov (United States)

Kwon, Min-Woo; Kim, Seung-Cheol; Kim, Eun-Soo

2016-01-20

A three-directional motion-compensation mask-based novel look-up table method is proposed and implemented on graphics processing units (GPUs) for video-rate generation of digital holographic videos of three-dimensional (3D) scenes. Since the proposed method is designed to be well matched with the software and memory structures of GPUs, the number of compute-unified-device-architecture kernel function calls can be significantly reduced. This results in a great increase of the computational speed of the proposed method, allowing video-rate generation of the computer-generated hologram (CGH) patterns of 3D scenes. Experimental results reveal that the proposed method can generate 39.8 frames of Fresnel CGH patterns with 1920×1080 pixels per second for the test 3D video scenario with 12,088 object points on dual GPU boards of NVIDIA GTX TITANs, and they confirm the feasibility of the proposed method in the practical application fields of electroholographic 3D displays.

Bulk viscosity in holographic Lifshitz hydrodynamics

International Nuclear Information System (INIS)

Hoyos, Carlos; Kim, Bom Soo; Oz, Yaron

2014-01-01

We compute the bulk viscosity in holographic models dual to theories with Lifshitz scaling and/or hyperscaling violation, using a generalization of the bulk viscosity formula derived in arXiv:1103.1657 from the null focusing equation. We find that only a class of models with massive vector fields are truly Lifshitz scale invariant, and have a vanishing bulk viscosity. For other holographic models with scalars and/or massless vector fields we find a universal formula in terms of the dynamical exponent and the hyperscaling violation exponent

Holographic corrections to meson scattering amplitudes

Energy Technology Data Exchange (ETDEWEB)

Armoni, Adi; Ireson, Edwin, E-mail: 746616@swansea.ac.uk

2017-06-15

We compute meson scattering amplitudes using the holographic duality between confining gauge theories and string theory, in order to consider holographic corrections to the Veneziano amplitude and associated higher-point functions. The generic nature of such computations is explained, thanks to the well-understood nature of confining string backgrounds, and two different examples of the calculation in given backgrounds are used to illustrate the details. The effect we discover, whilst only qualitative, is re-obtainable in many such examples, in four-point but also higher point amplitudes.

Organic liquids as ''activ media'' in a holographic ionizing radiation dosimeter

International Nuclear Information System (INIS)

Nicolau-Rebigan, S.

1979-01-01

Some types of organic liquids for using as activ media in a holographic ionizing radiation dosimeter are presented. One outlined the advantages of the holographic dosimeter comparatively with those of common used dosimeters. One presented the advantages of utilization of the organic liquids comparatively with another chemical systems used in a holographic ionizing radiation dosimeter. (author)

Holographic dark energy and f(R) gravity

Energy Technology Data Exchange (ETDEWEB)

Aghamohammadi, A [Faculty of Science, Islamic Azad University of Sanandaj, Sanandaj (Iran, Islamic Republic of); Saaidi, Kh, E-mail: ksaaidi@uok.ac.ir, E-mail: agha35484@yahoo.com [Department of Physics, Faculty of Science, University of Kurdistan, Sanandaj (Iran, Islamic Republic of)

2011-02-15

We investigate the corresponding relation between f(R) gravity and holographic dark energy. We introduce a type of energy density from f(R) that has the same role as holographic dark energy. We obtain the differential equation that specifies the evolution of the introduced energy density parameter based on a varying gravitational constant. We discover the relation for the equation of state parameter for low redshifts that contains varying G correction.

Application of DuPont photopolymer films to automotive holographic display

Science.gov (United States)

Nakazawa, Norihito; Ono, Motoshi; Takeuchi, Shoichi; Sakurai, Hiromi; Hirano, Masahiro

1998-03-01

Automotive holographic head-up display (HUD) systems employing DuPont holographic photopolymer films are presented. Holographic materials for automotive application are exposed to severe environmental conditions and are required high performance. This paper describes the improvement of DuPont photopolymer films for the automotive use, critical technical issues such as optical design, external color and stray light. The holographic HUD combiner embedded in a windshield of an automobile has peculiar problems called external color. Diffraction light from holographic combiner makes its external color tone stimulative. We have introduced RGB three color recording and color simulation in order to improve the external color. A moderate external color tone was realized by the optimization in terms of wavelengths and diffraction efficiencies of the combiner hologram. The stray light called flare arises from a reflection by glass surface of windshield. We have developed two techniques to avoid the flare. First is a diffuser type trap beam guard hologram which reduces the intensity of the flare. Second is the optimization of the design of hologram so that the incident direction of flare is lower than the horizon line. As an example of automotive display a stand-alone type holographic HUD system attached on the dashboard of an automobile is demonstrated, which provides useful driving information such as route guidance. The display has a very simple optical system that consists of only a holographic combiner and a vacuum fluorescent display. Its thin body is only 35 mm high and does not obstruct driver's view. The display gives high contrast and wide image.

Holographic Chern-Simons defects

International Nuclear Information System (INIS)

Fujita, Mitsutoshi; Melby-Thompson, Charles M.; Meyer, René; Sugimoto, Shigeki

2016-01-01

We study SU(N) Yang-Mills-Chern-Simons theory in the presence of defects that shift the Chern-Simons level from a holographic point of view by embedding the system in string theory. The model is a D3-D7 system in Type IIB string theory, whose gravity dual is given by the AdS soliton background with probe D7 branes attaching to the AdS boundary along the defects. We holographically renormalize the free energy of the defect system with sources, from which we obtain the correlation functions for certain operators naturally associated to these defects. We find interesting phase transitions when the separation of the defects as well as the temperature are varied. We also discuss some implications for the Fractional Quantum Hall Effect and for 2-dimensional QCD.

Holographic entanglement entropy in 2D holographic superconductor via AdS3/CFT2

Directory of Open Access Journals (Sweden)

Davood Momeni

2015-07-01

Full Text Available The aim of the present letter is to find the holographic entanglement entropy (HEE in 2D holographic superconductors (HSC. Indeed, it is possible to compute the exact form of this entropy due to an advantage of approximate solutions inside normal and superconducting phases with backreactions. By making the UV and IR limits applied to the integrals, an approximate expression for HEE is obtained. In case the software cannot calculate minimal surface integrals analytically, it offers the possibility to proceed with a numerical evaluation of the corresponding terms. We'll understand how the area formula incorporates the structure of the domain wall approximation. We see that HEE changes linearly with belt angle. It's due to the extensivity of this type of entropy and the emergent of an entropic force. We find that the wider belt angle corresponds to a larger holographic surface. Another remarkable observation is that no “confinement/deconfinement” phase transition point exists in our 2D dual field theory. Furthermore, we observe that the slope of the HEE with respect to the temperature dSdT decreases, thanks to the emergence extra degree of freedom(s in low temperature system. A first order phase transition is detected near the critical point.

Coaxial waveguide mode reconstruction and analysis with THz digital holography.

Science.gov (United States)

Wang, Xinke; Xiong, Wei; Sun, Wenfeng; Zhang, Yan

2012-03-26

Terahertz (THz) digital holography is employed to investigate the properties of waveguides. By using a THz digital holographic imaging system, the propagation modes of a metallic coaxial waveguide are measured and the mode patterns are restored with the inverse Fresnel diffraction algorithm. The experimental results show that the THz propagation mode inside the waveguide is a combination of four modes TE₁₁, TE₁₂, TM₁₁, and TM₁₂, which are in good agreement with the simulation results. In this work, THz digital holography presents its strong potential as a platform for waveguide mode charactering. The experimental findings provide a valuable reference for the design of THz waveguides.

Programmable pulse generator

International Nuclear Information System (INIS)

Xue Zhihua; Lou Binqiao; Duan Xiaohui

2002-01-01

The author introduces the design of programmable pulse generator that is based on a micro-controller and controlled by RS232 interface of personal computer. The whole system has good stability. The pulse generator can produce TTL pulse and analog pulse. The pulse frequency can be selected by EPLD. The voltage amplitude and pulse width of analog pulse can be adjusted by analog switches and digitally-controlled potentiometers. The software development tools of computer is National Instruments LabView5.1. The front panel of this virtual instrumentation is intuitive and easy-to-use. Parameters can be selected and changed conveniently by knob and slide

Covariant generalized holographic dark energy and accelerating universe

Energy Technology Data Exchange (ETDEWEB)

Nojiri, Shin' ichi [Nagoya University, Department of Physics, Nagoya (Japan); Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya (Japan); Odintsov, S.D. [ICREA, Barcelona (Spain); Institute of Space Sciences (IEEC-CSIC), Barcelona (Spain); National Research Tomsk State University, Tomsk (Russian Federation); Tomsk State Pedagogical University, Tomsk (Russian Federation)

2017-08-15

We propose the generalized holographic dark energy model where the infrared cutoff is identified with the combination of the FRW universe parameters: the Hubble rate, particle and future horizons, cosmological constant, the universe lifetime (if finite) and their derivatives. It is demonstrated that with the corresponding choice of the cutoff one can map such holographic dark energy to modified gravity or gravity with a general fluid. Explicitly, F(R) gravity and the general perfect fluid are worked out in detail and the corresponding infrared cutoff is found. Using this correspondence, we get realistic inflation or viable dark energy or a unified inflationary-dark energy universe in terms of covariant holographic dark energy. (orig.)

Covariant generalized holographic dark energy and accelerating universe

International Nuclear Information System (INIS)

Nojiri, Shin'ichi; Odintsov, S.D.

2017-01-01

We propose the generalized holographic dark energy model where the infrared cutoff is identified with the combination of the FRW universe parameters: the Hubble rate, particle and future horizons, cosmological constant, the universe lifetime (if finite) and their derivatives. It is demonstrated that with the corresponding choice of the cutoff one can map such holographic dark energy to modified gravity or gravity with a general fluid. Explicitly, F(R) gravity and the general perfect fluid are worked out in detail and the corresponding infrared cutoff is found. Using this correspondence, we get realistic inflation or viable dark energy or a unified inflationary-dark energy universe in terms of covariant holographic dark energy. (orig.)

Covariant generalized holographic dark energy and accelerating universe

Science.gov (United States)

Nojiri, Shin'ichi; Odintsov, S. D.

2017-08-01

We propose the generalized holographic dark energy model where the infrared cutoff is identified with the combination of the FRW universe parameters: the Hubble rate, particle and future horizons, cosmological constant, the universe lifetime (if finite) and their derivatives. It is demonstrated that with the corresponding choice of the cutoff one can map such holographic dark energy to modified gravity or gravity with a general fluid. Explicitly, F( R) gravity and the general perfect fluid are worked out in detail and the corresponding infrared cutoff is found. Using this correspondence, we get realistic inflation or viable dark energy or a unified inflationary-dark energy universe in terms of covariant holographic dark energy.

Numerical processing of ultrasonic holographic data

International Nuclear Information System (INIS)

Langenberg, K.J.; Kiefer, R.; Wosnitza, M.; Schmitz, V.; Fraunhofer-Gesellschaft zur Foerderung der Angewandten Forschung e.V., Saarbruecken

1980-01-01

Reconstructing ultrasonic holographic data numerically, the well-known Fresnel approximation is a first step in evaluating the Rayleigh-Sommerfeld diffraction formula, that is to say, a one- or two-dimensional Fourier-transform of the holographic data multiplied by a complex phase factor has to be computed. The present contribution investigates the relation between flaw depth and aperture size yielding the more advantageous use of the spatial frequency approach where the advantage is in terms of the number of samples and hence computation time in evaluating Fourier transforms numerically. (orig.) [de

Holographic dark energy in the DGP model

International Nuclear Information System (INIS)

Cruz, Norman; Lepe, Samuel; Pena, Francisco; Avelino, Arturo

2012-01-01

The braneworld model proposed by Dvali, Gabadadze, and Porrati leads to an accelerated universe without cosmological constant or any other form of dark energy. Nevertheless, we have investigated the consequences of this model when an holographic dark energy is included, taking the Hubble scale as IR cutoff. We have found that the holographic dark energy leads to an accelerated flat universe (de Sitter-like expansion) for the two branches: ε=±1, of the DGP model. Nevertheless, in universes with no null curvature the dark energy presents an EoS corresponding to a phantom fluid during the present era and evolving to a de Sitter-like phase for future cosmic time. In the special case in which the holographic parameter c is equal to one we have found a sudden singularity in closed universes. In this case the expansion is decelerating. (orig.)

Holographic dark energy in the DGP model

Energy Technology Data Exchange (ETDEWEB)

Cruz, Norman [Universidad de Santiago, Departamento de Fisica, Facultad de Ciencia, Santiago (Chile); Lepe, Samuel [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Facultad de Ciencias, Valparaiso (Chile); Pena, Francisco [Universidad de La Frontera, Departamento de Ciencias Fisicas, Facultad de Ingenieria, Ciencias y Administracion, Avda. Francisco Salazar 01145, Casilla 54-D, Temuco (Chile); Avelino, Arturo [Universidad de Guanajuato, Departamento de Fisica, DCI, Codigo Postal 37150, Leon, Guanajuato (Mexico)

2012-09-15

The braneworld model proposed by Dvali, Gabadadze, and Porrati leads to an accelerated universe without cosmological constant or any other form of dark energy. Nevertheless, we have investigated the consequences of this model when an holographic dark energy is included, taking the Hubble scale as IR cutoff. We have found that the holographic dark energy leads to an accelerated flat universe (de Sitter-like expansion) for the two branches: {epsilon}={+-}1, of the DGP model. Nevertheless, in universes with no null curvature the dark energy presents an EoS corresponding to a phantom fluid during the present era and evolving to a de Sitter-like phase for future cosmic time. In the special case in which the holographic parameter c is equal to one we have found a sudden singularity in closed universes. In this case the expansion is decelerating. (orig.)

Holographic representation of space-variant systems: system theory.

Science.gov (United States)

Marks Ii, R J; Krile, T F

1976-09-01

System theory for holographic representation of linear space-variant systems is derived. The utility of the resulting piecewise isoplanatic approximation (PIA) is illustrated by example application to the invariant system, ideal magnifier, and Fourier transformer. A method previously employed to holographically represent a space-variant system, the discrete approximation, is shown to be a special case of the PIA.

Chemical systems in aqueous solutions for using in the holographic ionizing radiation

International Nuclear Information System (INIS)

Nicolau-Rebigan, S.

1979-01-01

Some types of chemical systems in aqueous solutions for utilization as active media in holographic ionizing radiation dosimeter are presented. One discussed some advantages of the holographic dosimeter comparatively with another existing types. It is outlined the advantages of using aqueousss solutions as active media in holographic dosimeter. (author)

Environmental stability study of holographic solar spectrum splitting materials

Science.gov (United States)

Chrysler, Benjamin D.; Ayala Pelaez, Silvana; Wu, Yuechen; Vorndran, Shelby D.; Kostuk, Raymond K.

2016-09-01

In this study the impact of outdoor temperature variations and solar illumination exposure on spectral filter material and holographic optical elements is examined. Although holographic components have been shown to be useful for solar spectrum splitting designs, relatively little quantitative data exist to demonstrate the extent to which these materials can withstand outdoor conditions. As researchers seek to investigate practical spectrum splitting designs, the environmental stability of holographic materials should be considered as an important factor. In the experiment presented, two holographic materials, Covestro Bayfol HX photopolymer and dichromated gelatin, and 3M reflective polymer filter materials are exposed to outdoor conditions for a period of several months. The environmental effect on absorption, spectral and angular bandwidth, peak efficiency, and Bragg matching conditions for the holograms are examined. Spectral bandwidth and transmittance of the 3M reflective filter material are also monitored. Holographic gratings are recorded, measured, and mounted on glass substrates and then sealed with a glass cover plate. The test samples are then mounted on a photovoltaic panel to simulate realistic temperature conditions and placed at an outdoor test facility in Tucson, Arizona. A duplicate set of holograms and 3M filter material is stored as a control group and periodically compared over the test period.

First law of thermodynamics on holographic screens in entropic force frame

International Nuclear Information System (INIS)

Chen Yixin; Li Jianlong

2011-01-01

Imposing a mathematical definition of holographic screen, in the spirit of Verlinde's entropic force proposal (E.P. Verlinde, (arXiv:1001.0785)), we give the differential and integral form of the first law of thermodynamics on the holographic screen enclosing a spherical symmetric black hole. It is consistent with equipartition principle and the form of Komar mass. There are also other version of first law, which are equivalent up to a Legendre transformation. The holographic screen thermodynamics is defined in a quasi-local form, which is the main difference to black hole thermodynamics. Thus, the physical interpretation of holographic screen thermodynamics might be different from black hole thermodynamics. We argue that the entropy of the holographic screen determines its area, i.e. S=A/4 . And the metric can be expressed by thermodynamics variables, which is an illustration of how the space is foliated by the thermodynamical potentials.

Realization of an optical interferometer based on holographic optics ...

Indian Academy of Sciences (India)

The paper describes a simple and cost effective method for the realization of an optical interferometer based on holographic optics, which use minimal bulk optical components. The optical arrangement in the proposed method involves a very simple alignment procedure and inexpensive holographic recording material is ...

Emergent Gauge Fields in Holographic Superconductors

CERN Document Server

Domènech, Oriol; Pomarol, Alex; Salvio, Alberto; Silva, Pedro J

2010-01-01

Holographic superconductors have been studied so far in the absence of dynamical electromagnetic fields, namely in the limit in which they coincide with holographic superfluids. It is possible, however, to introduce dynamical gauge fields if a Neumann-type boundary condition is imposed on the AdS-boundary. In 3+1 dimensions, the dual theory is a 2+1 dimensional CFT whose spectrum contains a massless gauge field, signaling the emergence of a gauge symmetry. We study the impact of a dynamical gauge field in vortex configurations where it is known to significantly affect the energetics and phase transitions. We calculate the critical magnetic fields H_c1 and H_c2, obtaining that holographic superconductors are of Type II (H_c1 < H_c2). We extend the study to 4+1 dimensions where the gauge field does not appear as an emergent phenomena, but can be introduced, by a proper renormalization, as an external dynamical field. We also compare our predictions with those arising from a Ginzburg-Landau theory and identif...

A novel holographic technique for strain and deformation measurement

International Nuclear Information System (INIS)

Ettemeyer, A.

1988-01-01

A complete holographic system is presented after a description of the holographic measurement principle and of the fundamentals of three-dimensional deformation and dilatation analysis. The new holographic system permits quasi-simultaneous measurements from three extremely divergent directions. For this purpose, the object is illuminated and observed from each of three perspectives. To avoid perturbing interferences and Moire effects, the laser beam is split up into three beams which are no longer coherent with each other. In this way, three holograms are produced in various sections of a single holographic plate. The holograms for the three measurement directions are evaluated with the help of a computer (Phase-shift method). A picture rectification is effected to compensate for the distortion of the object's perspectives due to diverging directions of observation. The three-dimensional shifting components of the displacement vector are calculated for each point of the object's surface. The expansion of the object's surface is derived from these calculations, by means of differentiation. (orig./HP) [de

Quantitative pulsed eddy current analysis

International Nuclear Information System (INIS)

Morris, R.A.

1975-01-01

The potential of pulsed eddy current testing for furnishing more information than conventional single-frequency eddy current methods has been known for some time. However, a fundamental problem has been analyzing the pulse shape with sufficient precision to produce accurate quantitative results. Accordingly, the primary goal of this investigation was to: demonstrate ways of digitizing the short pulses encountered in PEC testing, and to develop empirical analysis techniques that would predict some of the parameters (e.g., depth) of simple types of defect. This report describes a digitizing technique using a computer and either a conventional nuclear ADC or a fast transient analyzer; the computer software used to collect and analyze pulses; and some of the results obtained. (U.S.)

Proton beam writing for producing holographic images

International Nuclear Information System (INIS)

Ow, Y.S.; Breese, M.B.H.; Bettiol, A.A.

2009-01-01

This work reports on the writing of computer generated hologram diffraction patterns using focused 2 MeV proton beam irradiation. These patterns were designed using a ray tracing algorithm and written directly into a thick polymethylmethacrylate layer. When the developed holographic pattern was illuminated with a 650 nm laser it produced a good reconstructed image. This work provides means of forming high-resolution, high aspect ratio holographic images in polymers for applications in data storage using switchable holography.

Software for analysis of waveforms acquired by digital Doppler broadening spectrometer

International Nuclear Information System (INIS)

Vlcek, M; Čížek, J; Procházka, I

2013-01-01

High-resolution digital spectrometer for coincidence measurement of Doppler broadening of positron annihilation radiation was recently developed and tested. In this spectrometer pulses from high purity Ge (HPGe) detectors are sampled in the real time by fast digitizers and subsequently analyzed off-line by software. We present description of the software routines used for pulse shape analysis in two spectrometer configurations: (i) semi-digital setup in which detector pulses shaped in spectroscopic amplifiers (SA's) are digitized; (ii) pure digital setup in which pulses from detector pre-amplifiers are digitized directly. Software developed in this work will be freely available in the form of source code and pre-compiled binaries.

A holographic waveguide based eye tracker

Science.gov (United States)

Liu, Changgeng; Pazzucconi, Beatrice; Liu, Juan; Liu, Lei; Yao, Xincheng

2018-02-01

We demonstrated the feasibility of using holographic waveguide for eye tracking. A custom-built holographic waveguide, a 20 mm x 60 mm x 3 mm flat glass substrate with integrated in- and out-couplers, was used for the prototype development. The in- and out-couplers, photopolymer films with holographic fringes, induced total internal reflection in the glass substrate. Diffractive optical elements were integrated into the in-coupler to serve as an optical collimator. The waveguide captured images of the anterior segment of the eye right in front of it and guided the images to a processing unit distant from the eye. The vector connecting the pupil center (PC) and the corneal reflex (CR) of the eye was used to compute eye position in the socket. An eye model, made of a high quality prosthetic eye, was used prototype validation. The benchtop prototype demonstrated a linear relationship between the angular eye position and the PC/CR vector over a range of 60 horizontal degrees and 30 vertical degrees at a resolution of 0.64-0.69 degrees/pixel by simple pixel count. The uncertainties of the measurements at different angular positions were within 1.2 pixels, which indicated that the prototype exhibited a high level of repeatability. These results confirmed that the holographic waveguide technology could be a feasible platform for developing a wearable eye tracker. Further development can lead to a compact, see-through eye tracker, which allows continuous monitoring of eye movement during real life tasks, and thus benefits diagnosis of oculomotor disorders.

Shrinkage measurement for holographic recording materials

Science.gov (United States)

Fernández, R.; Gallego, S.; Márquez, A.; Francés, J.; Navarro Fuster, V.; Neipp, C.; Ortuño, M.; Beléndez, A.; Pascual, I.

2017-05-01

There is an increasing demand for new holographic recording materials. One of them are photopolymers, which are becoming a classic media in this field. Their versatility is well known and new possibilities are being created by including new components, such as nanoparticles or dispersed liquid crystal molecules in classical formulations, making them interesting for additional applications in which the thin film preparation and the structural modification have a fundamental importance. Prior to obtaining a wide commercialization of displays based on photopolymers, one of the key aspects is to achieve a complete characterization of them. In this sense, one of the main parameters to estimate and control is the shrinkage of these materials. The volume variations change the angular response of the hologram in two aspects, the angular selectivity and the maximum diffraction efficiency. One criteria for the recording material to be used in a holographic data storage application is the shrinkage, maximum of 0.5%. Along this work, we compare two different methods to measure the holographic recording material shrinkage. The first one is measuring the angle of propagation for both diffracted orders +/-1 when slanted gratings are recorded, so that an accurate value of the grating vector can be calculated. The second one is based on interference measurements at zero spatial frequency limit. We calculate the shrinkage for three different photopolymers: a polyvinyl alcohol acrylamide (PVA/AA) based photopolymer, one of the greenest photopolymers whose patent belongs to the Alicante University called Biophotopol and on the last place a holographic-dispersed liquid crystal photopolymer (H-PDLC).

Holographic method coupled with an optoelectronic interface applied in the ionizing radiation dosimetry

International Nuclear Information System (INIS)

Nicolau-Rebigan, S.; Sporea, D.; Niculescu, V.I.R.

2000-01-01

The paper presents a holographic method applied in the ionizing radiation dosimetry. It is possible to use two types of holographic interferometry like as double exposure holographic interferometry, or fast real time holographic interferometry. In this paper the applications of holographic interferometry to ionizing radiation dosimetry are presented. The determination of the accurate value of dose delivered by an ionizing radiation source (released energy per mass unit) is a complex problem which imposes different solutions depending on experimental parameters and it is solved with a double exposure holographic interferometric method associated with an optoelectronic interface and Z80 microprocessor. The method can determine the absorbed integral dose as well as the three-dimensional distribution of dose in given volume. The paper presents some results obtained in radiation dosimetry. Original mathematical relations for integral absorbed dose in irreversible radiolyzing liquids where derived. Irradiation effects can be estimated from the holographic fringes displacement and density. To measure these parameters, the obtained holographic interferograms were picked-up by a closed TV circuit system in such a way that a selected TV line explores the picture along the direction of interest using a special designed interface, a Z80 and our microprocessor system captures data along the selected TV line. When the integral dose is to be measured the microprocessor computes it from the information contained in the fringes distribution, according to the proposed formulae. Integral absorbed dose and spatial dose distribution can be estimated with an accuracy better than 4%. Some advantages of this method are outlined comparatively with conventional method in radiation dosimetry. The paper presents an original holographic set-up with an electronic interface, assisted by a Z80 microprocessor and used for nondestructive testing of transparent objects at the laser wave length

Real-time Holographic Display Based on a Super Fast Response Thin Film

International Nuclear Information System (INIS)

Gao, Hongyue; Li, Xiao; He, Zhenghong; Su, Yikai; Poon, Ting-Chung

2013-01-01

Real-time dynamic holographic display is obtained with super fast response in a thin film without any applied electric field. Holograms can be refreshed in the order of a millisecond and there is no cross talk between the recorded holograms because the hologram formed in the film is transient and can be completely self erased, and the hologram formation time and self-erasure time are both ∼1 ms. Holographic video display is achieved, which shows the real-time holographic image display capability of the thin film, and its much higher resolution than those of commercially available spatial light modulators. Furthermore, multiplexed hologram display using two polarization directions of a recorded light and multiple color holographic display at different laser wavelengths are presented, which demonstrate the feasibility of a RGB color holographic three-dimensional display with the thin film. Because the sample is easy to be fabricated into a large size screen and needs no external applied electric field, we think that the film can be developed into a large-size, dynamic, and color holographic three-dimensional display in the future.

Real-time wideband holographic surveillance system

Science.gov (United States)

Sheen, D.M.; Collins, H.D.; Hall, T.E.; McMakin, D.L.; Gribble, R.P.; Severtsen, R.H.; Prince, J.M.; Reid, L.D.

1996-09-17

A wideband holographic surveillance system including a transceiver for generating a plurality of electromagnetic waves; antenna for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; the transceiver also receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; a computer for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and a display for displaying the processed information to determine nature of the target. The computer has instructions to apply a three dimensional backward wave algorithm. 28 figs.

Volume phase holographic grating used for beams combination of RGB primary colors

Science.gov (United States)

Liu, Hui; Zhang, Xizhao; Tang, Minxue

2013-12-01

Volume phase holographic grating (VPHG) has the characteristics of high diffraction efficiency, high signal to noise ratio, high wavelength and angular selectivity, low scattering , low absorption and low cost. It has been widely used in high resolution spectrometer, wavelength division multiplexing and pulse compression technique. In this paper, a novel kind of RGB primary colors beams combiner which is consisted of a transmission VPHG and a reflection VPHG as core components is proposed. The design idea of the element is described in detail. Based on the principle of VPHG, the rigorous coupled wave analysis (RCWA) and Kogelnik's coupled wave theory, diffraction properties of the transmission and reflection VPHG are studied theoretically. As an example, three primary colors at wavelengths of 632.8nm, 532nm and 476.5nm are taken into account. Dichromated gelatin (DCG) is used as the holographic recording material. The grating parameters are determined by the Bragg conditions. The TE and TM wave diffraction efficiency, the wavelength selectivity and the angular selectivity of the transmission and reflection VPHG are calculated and optimized by setting the amplitude of the index modulation (Δn) and the thickness of the gelatin layer (d) by applying Kogelnik's coupled wave theory and G-solver software, respectively. The theoretical calculating results give guidance for further manufacture of the element.

Inflation via logarithmic entropy-corrected holographic dark energy model

Energy Technology Data Exchange (ETDEWEB)

Darabi, F.; Felegary, F. [Azarbaijan Shahid Madani University, Department of Physics, Tabriz (Iran, Islamic Republic of); Setare, M.R. [University of Kurdistan, Department of Science, Bijar (Iran, Islamic Republic of)

2016-12-15

We study the inflation in terms of the logarithmic entropy-corrected holographic dark energy (LECHDE) model with future event horizon, particle horizon, and Hubble horizon cut-offs, and we compare the results with those obtained in the study of inflation by the holographic dark energy HDE model. In comparison, the spectrum of primordial scalar power spectrum in the LECHDE model becomes redder than the spectrum in the HDE model. Moreover, the consistency with the observational data in the LECHDE model of inflation constrains the reheating temperature and Hubble parameter by one parameter of holographic dark energy and two new parameters of logarithmic corrections. (orig.)

Design and evaluation of daylighting applications of holographic glazings

Energy Technology Data Exchange (ETDEWEB)

Papamichael, K.; Ehrlich, C.; Ward, G.

1996-12-01

According to the contractual agreement, BTP would develop a computer model of the POC holographic structures and then simulate the performance of alternative designs using the RADIANCE lighting and rendering computer program [Ward 1990]. The RADIANCE model would then be used to evaluate the daylight performance of alternative designs of holographic glazings in a prototypical office space. The simulation process would be validated against actual photometric measurements of holographic glazing samples developed by POC. The results would be used to evaluate the potential for increased electric lighting savings through increased daylight illuminance levels at distances more than 15 ft--20 ft (4.6 m--6.1 m ) from the window wall.

Inflation via logarithmic entropy-corrected holographic dark energy model

International Nuclear Information System (INIS)

Darabi, F.; Felegary, F.; Setare, M.R.

2016-01-01

We study the inflation in terms of the logarithmic entropy-corrected holographic dark energy (LECHDE) model with future event horizon, particle horizon, and Hubble horizon cut-offs, and we compare the results with those obtained in the study of inflation by the holographic dark energy HDE model. In comparison, the spectrum of primordial scalar power spectrum in the LECHDE model becomes redder than the spectrum in the HDE model. Moreover, the consistency with the observational data in the LECHDE model of inflation constrains the reheating temperature and Hubble parameter by one parameter of holographic dark energy and two new parameters of logarithmic corrections. (orig.)

Holographic and acoustic emission evaluation of pressure vessels

International Nuclear Information System (INIS)

Boyd, D.M.

1980-01-01

Optical holographic interfereometry and acoustic emission monitoring were simultaneously used to evaluate two small, high pressure vessels during pressurization. The techniques provide pressure vessel designers with both quantitative information such as displacement/strain measurements and qualitative information such as flaw detection. The data from the holographic interferograms were analyzed for strain profiles. The acoustic emission signals were monitored for crack growth and vessel quality

Real-time vibration measurement by a spatial phase-shifting technique with a tilted holographic interferogram.

Science.gov (United States)

Nakadate, S; Isshiki, M

1997-01-01

Real-time vibration measurement by a tilted holographic interferogram is presented that utilizes the real-time digital fringe processor of a video signal. Three intensity data sampled at every one-third of the fringe spacing of the tilted fringes are used to calculate the modulation term of the fringe that is a function of a vibration amplitude. A three-dimensional lookup table performs the calculation in a TV repetition rate to give a new fringe profile that contours the vibration amplitude. Vibration modes at the resonant frequencies of a flat speaker were displayed on a monitor as changing the exciting frequency of vibration.

Entanglement between two interacting CFTs and generalized holographic entanglement entropy

International Nuclear Information System (INIS)

Mollabashi, Ali; Shiba, Noburo; Takayanagi, Tadashi

2014-01-01

In this paper we discuss behaviors of entanglement entropy between two interacting CFTs and its holographic interpretation using the AdS/CFT correspondence. We explicitly perform analytical calculations of entanglement entropy between two free scalar field theories which are interacting with each other in both static and time-dependent ways. We also conjecture a holographic calculation of entanglement entropy between two interacting N=4 super Yang-Mills theories by introducing a minimal surface in the S 5 direction, instead of the AdS 5 direction. This offers a possible generalization of holographic entanglement entropy

Digital neutron–gamma discrimination with scintillators: An innovative approach

International Nuclear Information System (INIS)

Jamili, S.; Bayat, E.; Ghal–Eh, N.

2017-01-01

In this paper, a digital neutron–gamma discrimination (DNGD) method with an NE213 scintillator has been proposed in which the anode pulse is divided into two different pulses, one representing the amplitude and the other characterizes the DNGD. Then the two pulses are summed up after travelling through delay and mixer circuits to form an input pulse for sampling in analog–to–digital converter (ADC). The discrimination tests have been performed with an 8–bit digital storage oscilloscope (DSO) as ADC and 241 Am–Be neutron source, whereas the Fourier method has been used to derive the discrimination characteristic. The results confirm the fast performance and efficiency of proposed method. - Highlights: • A digital n–γ discrimination (DNGD) method with an NE213 scintillator has been proposed. • The anode pulse is divided into two pulses, one for amplitude and the other for DNGD characterizations. • The two pulses are summed up after delay and mixing to form an input pulse for an ADC. • The DNGD results confirm the fast performance and efficiency of proposed method.

Drawing Lines with Light in Holographic Space

International Nuclear Information System (INIS)

Chang, Yin-Ren; Richardson, Martin

2013-01-01

This paper explores the dynamic and expressive possibilities of holographic art through a comparison of art history and technical media such as photography, film and holographic technologies. Examples of modern art and creative expression of time and motions are examined using the early 20th century art movement, Cubism, where subjects are portrayed to be seen simultaneously from different angles. Folding space is represented as subject matter as it can depict space from multiple points of time. The paper also investigates the way holographic art has explored time and space. The lenticular lens-based media reveal a more subjective poetic art in the form of the lyrical images and messages as spectators pass through time, or walk along with the piece of work through an interactive process. It is argued that photographic practice is another example of artistic representation in the form of aesthetic medium of time movement and as such shares a common ground with other dynamic expression that require time based interaction.

Effect of quintessence on holographic fermionic spectrum

Energy Technology Data Exchange (ETDEWEB)

Kuang, Xiao-Mei [Yangzhou University, Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou (China); Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile); Wu, Jian-Pin [Bohai University, Institute of Gravitation and Cosmology, Department of Physics, School of Mathematics and Physics, Jinzhou (China)

2017-10-15

In this letter, we investigate the holographic fermionic spectrum without/with dipole coupling dual to the Reissner-Nordstroem anti-de Sitter (RN-AdS) black brane surrounded by quintessence. We find that the low energy excitation of this fermionic system without dipole coupling behaves as a non-Fermi liquid. In particular, the introduction of quintessence aggravates the degree of deviation from a Fermi liquid. For the system with dipole coupling, the phase transition from (non-)Fermi liquid to Mott phase can be observed. The ratio between the width of gap and the critical temperature, beyond which the gap closes, is also worked out. We find that this ratio is larger than that of the holographic fermionic system dual to the RN-AdS black brane and even the material of V O{sub 2}. It means that our holographic system with quintessence can model new phenomena of the condensed matter system and provide some new insights in their regard. (orig.)

Holographic dark energy in Brans-Dicke cosmology with chameleon scalar field

Energy Technology Data Exchange (ETDEWEB)

Setare, M.R., E-mail: rezakord@ipm.i [Department of Science of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Jamil, Mubasher, E-mail: mjamil@camp.edu.p [Center for Advanced Mathematics and Physics, National University of Sciences and Technology, Rawalpindi 46000 (Pakistan)

2010-06-07

We study a cosmological implication of holographic dark energy in the Brans-Dicke gravity. We employ the holographic model of dark energy to obtain the equation of state for the holographic energy density in non-flat (closed) universe enclosed by the event horizon measured from the sphere of horizon named L. Our analysis shows that one can obtain the phantom crossing scenario if the model parameter {alpha} (of order unity) is tuned accordingly. Moreover, this behavior is achieved by treating the Brans-Dicke scalar field as a Chameleon scalar field and taking a non-minimal coupling of the scalar field with matter. Hence one can generate phantom-like equation of state from a holographic dark energy model in non-flat universe in the Brans-Dicke cosmology framework.

Holographic dark energy in Brans-Dicke cosmology with chameleon scalar field

International Nuclear Information System (INIS)

Setare, M.R.; Jamil, Mubasher

2010-01-01

We study a cosmological implication of holographic dark energy in the Brans-Dicke gravity. We employ the holographic model of dark energy to obtain the equation of state for the holographic energy density in non-flat (closed) universe enclosed by the event horizon measured from the sphere of horizon named L. Our analysis shows that one can obtain the phantom crossing scenario if the model parameter α (of order unity) is tuned accordingly. Moreover, this behavior is achieved by treating the Brans-Dicke scalar field as a Chameleon scalar field and taking a non-minimal coupling of the scalar field with matter. Hence one can generate phantom-like equation of state from a holographic dark energy model in non-flat universe in the Brans-Dicke cosmology framework.

Electromagnetic holographic sensitivity field of two-phase flow in horizontal wells

Science.gov (United States)

Zhang, Kuo; Wu, Xi-Ling; Yan, Jing-Fu; Cai, Jia-Tie

2017-03-01

Electromagnetic holographic data are characterized by two modes, suggesting that image reconstruction requires a dual-mode sensitivity field as well. We analyze an electromagnetic holographic field based on tomography theory and Radon inverse transform to derive the expression of the electromagnetic holographic sensitivity field (EMHSF). Then, we apply the EMHSF calculated by using finite-element methods to flow simulations and holographic imaging. The results suggest that the EMHSF based on the partial derivative of radius of the complex electric potential φ is closely linked to the Radon inverse transform and encompasses the sensitivities of the amplitude and phase data. The flow images obtained with inversion using EMHSF better agree with the actual flow patterns. The EMHSF overcomes the limitations of traditional single-mode sensitivity fields.

Counterterms and dual holographic anomalies in CS gravity

Energy Technology Data Exchange (ETDEWEB)

Banados, Maximo [Departamento de Fisica, P. Universidad Catolica de Chile, Casilla 306, Santiago 22, Chile (Chile); Olea, Rodrigo [Departamento de Fisica, P. Universidad Catolica de Chile, Casilla 306, Santiago 22, Chile (Chile); Theisen, Stefan [Max-Planck-Institut fuer Gravitationphysik, Albert-Einstein-Institut, 14476 Golm (Germany)

2005-10-15

The holographic Weyl anomaly associated to Chern-Simons gravity in 2n+1 dimensions is proportional to the Euler term in 2n dimensions, with no contributions from the Weyl tensor. We compute the holographic energy-momentum tensor associated to Chern-Simons gravity directly from the action, in an arbitrary odd-dimensional spacetime. We show, in particular, that the counterterms rendering the action finite contain only terms of the Lovelock type.

Three-dimensional counting of morphologically normal human red blood cells via digital holographic microscopy

Science.gov (United States)

Yi, Faliu; Moon, Inkyu; Lee, Yeon H.

2015-01-01

Counting morphologically normal cells in human red blood cells (RBCs) is extremely beneficial in the health care field. We propose a three-dimensional (3-D) classification method of automatically determining the morphologically normal RBCs in the phase image of multiple human RBCs that are obtained by off-axis digital holographic microscopy (DHM). The RBC holograms are first recorded by DHM, and then the phase images of multiple RBCs are reconstructed by a computational numerical algorithm. To design the classifier, the three typical RBC shapes, which are stomatocyte, discocyte, and echinocyte, are used for training and testing. Nonmain or abnormal RBC shapes different from the three normal shapes are defined as the fourth category. Ten features, including projected surface area, average phase value, mean corpuscular hemoglobin, perimeter, mean corpuscular hemoglobin surface density, circularity, mean phase of center part, sphericity coefficient, elongation, and pallor, are extracted from each RBC after segmenting the reconstructed phase images by using a watershed transform algorithm. Moreover, four additional properties, such as projected surface area, perimeter, average phase value, and elongation, are measured from the inner part of each cell, which can give significant information beyond the previous 10 features for the separation of the RBC groups; these are verified in the experiment by the statistical method of Hotelling's T-square test. We also apply the principal component analysis algorithm to reduce the dimension number of variables and establish the Gaussian mixture densities using the projected data with the first eight principal components. Consequently, the Gaussian mixtures are used to design the discriminant functions based on Bayesian decision theory. To improve the performance of the Bayes classifier and the accuracy of estimation of its error rate, the leaving-one-out technique is applied. Experimental results show that the proposed method can

Report on the set-up of a holographic interferometer

International Nuclear Information System (INIS)

Koster, J.N.

1977-10-01

Holographic interferometry is well suited for visualizing temperature, density, pressure and concentration fields in transparent fluids. The holographic real-time interferometer allows a continuous observation of stationary and instationary flow processes. After the explanation of the measuring technique, the problems arising during the interferometer set-up as well as the necessary adjusting operations are described. For heat transfer problems new possibilities for the application of holographic interferometry are revealed. Convection in boxes, temperature fields around heated or cooled bodies, concentration and diffusion processes in two phase-flows, mixtures and solutions as well as melting and freezing processes may be investigated. On the basis of particular examples some applications are presented. (orig.) [de

Sequential processing of quantitative phase images for the study of cell behaviour in real-time digital holographic microscopy.

Science.gov (United States)

Zikmund, T; Kvasnica, L; Týč, M; Křížová, A; Colláková, J; Chmelík, R

2014-11-01

Transmitted light holographic microscopy is particularly used for quantitative phase imaging of transparent microscopic objects such as living cells. The study of the cell is based on extraction of the dynamic data on cell behaviour from the time-lapse sequence of the phase images. However, the phase images are affected by the phase aberrations that make the analysis particularly difficult. This is because the phase deformation is prone to change during long-term experiments. Here, we present a novel algorithm for sequential processing of living cells phase images in a time-lapse sequence. The algorithm compensates for the deformation of a phase image using weighted least-squares surface fitting. Moreover, it identifies and segments the individual cells in the phase image. All these procedures are performed automatically and applied immediately after obtaining every single phase image. This property of the algorithm is important for real-time cell quantitative phase imaging and instantaneous control of the course of the experiment by playback of the recorded sequence up to actual time. Such operator's intervention is a forerunner of process automation derived from image analysis. The efficiency of the propounded algorithm is demonstrated on images of rat fibrosarcoma cells using an off-axis holographic microscope. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

Digital parallel-to-series pulse-train converter

Science.gov (United States)

Hussey, J.

1971-01-01

Circuit converts number represented as two level signal on n-bit lines to series of pulses on one of two lines, depending on sign of number. Converter accepts parallel binary input data and produces number of output pulses equal to number represented by input data.

Reusable holographic velocimetry system based on polarization multiplexing in Bacteriorhodopsin

NARCIS (Netherlands)

Koek, W.D.; Chan, V.S.S.; Ooms, T.A.; Bhattacharya, N.; Westerweel, J.; Braat, J.J.M.

2005-01-01

We present a novel holographic particle image velocimetry (HPIV) system using a reversible holographic material as the recording medium. In HPIV the three-dimensional flow field throughout a volume is detected by adding small tracer particles to a normally transparent medium. By recording the

Digital signal processing for He3 proportional counter

International Nuclear Information System (INIS)

Zeynalov, Sh.S.; Ahmadov, Q.S.

2010-01-01

Full text : Data acquisition systems for nuclear spectroscopy have traditionally been based on systems with analog shaping amplifiers followed by analog-to-digital converters. Recently, however, new systems based on digital signal processing make possible to replace the analog shaping and timing circuitry the numerical algorithms to derive properties of the pulse such as its amplitude. DSP is a fully numerical analysis of the detector pulse signals and this technique demonstrates significant advantages over analog systems in some circumstances. From a mathematical point of view, one can consider the signal evolution from the detector to the ADC as a sequence of transformations that can be described by precisely defined mathematical expressions. Digital signal processing with ADCs has the possibility to utilize further information on the signal pulses from radiation detectors. In the experiment each step of the signal generation in the 3He filled proportional counter was described using digital signal processing techniques (DSP). The electronic system has consisted of a detector, a preamplifier and a digital oscilloscope. The pulses from the detector were digitized using a digital storage oscilloscope. This oscilloscope allowed signal digitization with accuracy of 8 bit (256 levels) and with frequency of up to 5 * 10 8 samples/s. As a neutron source was used Cf-252. To obtain detector output current pulse I(t) created by the motions of the ions/electrons pairs was written an algorithm which can easily be programmed using modern computer programming languages.

Interacting holographic dark energy models: a general approach

Science.gov (United States)

Som, S.; Sil, A.

2014-08-01

Dark energy models inspired by the cosmological holographic principle are studied in homogeneous isotropic spacetime with a general choice for the dark energy density . Special choices of the parameters enable us to obtain three different holographic models, including the holographic Ricci dark energy (RDE) model. Effect of interaction between dark matter and dark energy on the dynamics of those models are investigated for different popular forms of interaction. It is found that crossing of phantom divide can be avoided in RDE models for β>0.5 irrespective of the presence of interaction. A choice of α=1 and β=2/3 leads to a varying Λ-like model introducing an IR cutoff length Λ -1/2. It is concluded that among the popular choices an interaction of the form Q∝ Hρ m suits the best in avoiding the coincidence problem in this model.

Deriving covariant holographic entanglement

Energy Technology Data Exchange (ETDEWEB)

Dong, Xi [School of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540 (United States); Lewkowycz, Aitor [Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Rangamani, Mukund [Center for Quantum Mathematics and Physics (QMAP), Department of Physics, University of California, Davis, CA 95616 (United States)

2016-11-07

We provide a gravitational argument in favour of the covariant holographic entanglement entropy proposal. In general time-dependent states, the proposal asserts that the entanglement entropy of a region in the boundary field theory is given by a quarter of the area of a bulk extremal surface in Planck units. The main element of our discussion is an implementation of an appropriate Schwinger-Keldysh contour to obtain the reduced density matrix (and its powers) of a given region, as is relevant for the replica construction. We map this contour into the bulk gravitational theory, and argue that the saddle point solutions of these replica geometries lead to a consistent prescription for computing the field theory Rényi entropies. In the limiting case where the replica index is taken to unity, a local analysis suffices to show that these saddles lead to the extremal surfaces of interest. We also comment on various properties of holographic entanglement that follow from this construction.

Rewritable three-dimensional holographic data storage via optical forces

Energy Technology Data Exchange (ETDEWEB)

Yetisen, Ali K., E-mail: ayetisen@mgh.harvard.edu [Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street, Cambridge, Massachusetts 02139 (United States); Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Montelongo, Yunuen [Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Butt, Haider [Nanotechnology Laboratory, School of Engineering Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom)

2016-08-08

The development of nanostructures that can be reversibly arranged and assembled into 3D patterns may enable optical tunability. However, current dynamic recording materials such as photorefractive polymers cannot be used to store information permanently while also retaining configurability. Here, we describe the synthesis and optimization of a silver nanoparticle doped poly(2-hydroxyethyl methacrylate-co-methacrylic acid) recording medium for reversibly recording 3D holograms. We theoretically and experimentally demonstrate organizing nanoparticles into 3D assemblies in the recording medium using optical forces produced by the gradients of standing waves. The nanoparticles in the recording medium are organized by multiple nanosecond laser pulses to produce reconfigurable slanted multilayer structures. We demonstrate the capability of producing rewritable optical elements such as multilayer Bragg diffraction gratings, 1D photonic crystals, and 3D multiplexed optical gratings. We also show that 3D virtual holograms can be reversibly recorded. This recording strategy may have applications in reconfigurable optical elements, data storage devices, and dynamic holographic displays.

Interacting holographic dark energy with logarithmic correction

International Nuclear Information System (INIS)

Jamil, Mubasher; Farooq, M. Umar

2010-01-01

The holographic dark energy (HDE) is considered to be the most promising candidate of dark energy. Its definition is motivated from the entropy-area relation which depends on the theory of gravity under consideration. Recently a new definition of HDE is proposed with the help of quantum corrections to the entropy-area relation in the setup of loop quantum cosmology. Employing this new definition, we investigate the model of interacting dark energy and derive its effective equation of state. Finally we establish a correspondence between generalized Chaplygin gas and entropy-corrected holographic dark energy

Single start multiple stop time digitizer

International Nuclear Information System (INIS)

Deshpande, P.A.; Mukhopadhyay, P.K.; Gopalakrishnan, K.R.

1997-01-01

A single start multiple stop time digitizer has been developed which can digitize the time between a start pulse and multiple stop pulses. The system has been designed as a PC add on card. The resolution of the instrument is 10 nSecs and the maximum length of time that it can measure is 1.28 milliseconds. Apart from time digitization, it can also resolve the height of the incoming pulses into 64 levels. After each input pulse the system dead time is less than 300 nSecs. The driver software for this card has been developed on DOS platform. It uses graphical user interface to provide a user friendly environment. The system is intended to be used in time of flight mass spectroscopy experiments. It can also be used for time of flight experiments in nuclear physics. (author). 2 figs

Multimode pulse counter

International Nuclear Information System (INIS)

Natanzon, D.D.

1982-01-01

A pulse counter with code conversion is described. The counter is based on the integrated circuits of direct-counting devices of medium integration. The counter ensures various modes of pulse counting depending on the logical control signals: reversible, two-channel summing, one-channel summing binary, summing with ''storage'' signal code fixation without interrupting pulse counting. Arrangement of the suggested structure as a microcircuit of medium integration might contribute to reduction in the counter type nomenclature in digital families of widely used integrated circuits

Digitization errors using digital charge division positionsensitive detectors

International Nuclear Information System (INIS)

Berliner, R.; Mildner, D.F.R.; Pringle, O.A.

1981-01-01

The data acquisition speed and electronic stability of a charge division position-sensitive detector may be improved by using digital signal processing with a table look-up high speed multiply to form the charge division quotient. This digitization process introduces a positional quantization difficulty which reduces the detector position sensitivity. The degree of the digitization error is dependent on the pulse height spectrum of the detector and on the resolution or dynamic range of the system analog-to-digital converters. The effects have been investigated analytically and by computer simulation. The optimum algorithm for position sensing determination using 8-bit digitization and arithmetic has a digitization error of less than 1%. (orig.)

Architecture for a 1-GHz Digital RADAR

Science.gov (United States)

Mallik, Udayan

2011-01-01

An architecture for a Direct RF-digitization Type Digital Mode RADAR was developed at GSFC in 2008. Two variations of a basic architecture were developed for use on RADAR imaging missions using aircraft and spacecraft. Both systems can operate with a pulse repetition rate up to 10 MHz with 8 received RF samples per pulse repetition interval, or at up to 19 kHz with 4K received RF samples per pulse repetition interval. The first design describes a computer architecture for a Continuous Mode RADAR transceiver with a real-time signal processing and display architecture. The architecture can operate at a high pulse repetition rate without interruption for an infinite amount of time. The second design describes a smaller and less costly burst mode RADAR that can transceive high pulse repetition rate RF signals without interruption for up to 37 seconds. The burst-mode RADAR was designed to operate on an off-line signal processing paradigm. The temporal distribution of RF samples acquired and reported to the RADAR processor remains uniform and free of distortion in both proposed architectures. The majority of the RADAR's electronics is implemented in digital CMOS (complementary metal oxide semiconductor), and analog circuits are restricted to signal amplification operations and analog to digital conversion. An implementation of the proposed systems will create a 1-GHz, Direct RF-digitization Type, L-Band Digital RADAR--the highest band achievable for Nyquist Rate, Direct RF-digitization Systems that do not implement an electronic IF downsample stage (after the receiver signal amplification stage), using commercially available off-the-shelf integrated circuits.

Holographic bounds on the UV cutoff scale in inflationary cosmology

DEFF Research Database (Denmark)

Keski-Vakkuri, Esko; Sloth, Martin Snoager

2003-01-01

We discuss how holographic bounds can be applied to the quantum fluctuations of the inflaton. In general the holographic principle will lead to a bound on the UV cutoff scale of the effective theory of inflation, but it will depend on the coarse-graining prescription involved in calculating...

Computer assisted holographic moire contouring

Science.gov (United States)

Sciammarella, Cesar A.

2000-01-01

Theoretical analyses and experimental results on holographic moire contouring on diffusely reflecting objects are presented. The sensitivity and limitations of the method are discussed. Particular emphasis is put on computer-assisted data retrieval, processing, and recording.

Magnonic holographic imaging of magnetic microstructures

Energy Technology Data Exchange (ETDEWEB)

Gutierrez, D.; Chiang, H.; Bhowmick, T.; Volodchenkov, A.D.; Ranjbar, M.; Liu, G.; Jiang, C.; Warren, C. [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States); Khivintsev, Y.; Filimonov, Y. [Kotelnikov Institute of Radioengineering and Electronics of Russian Academy of Sciences, Saratov Branch, Saratov 410019 (Russian Federation); Saratov State University, Saratov 410012 (Russian Federation); Garay, J.; Lake, R.; Balandin, A.A. [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States); Khitun, A., E-mail: akhitun@engr.ucr.edu [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States)

2017-04-15

We propose and demonstrate a technique for magnetic microstructure imaging via their interaction with propagating spin waves. In this approach, the object of interest is placed on top of a magnetic testbed made of material with low spin wave damping. There are micro-antennas incorporated in the testbed. Two of these antennas are used for spin wave excitation while another one is used for the detecting of inductive voltage produced by the interfering spin waves. The measurements are repeated for different phase differences between the spin wave generating antennas which is equivalent to changing the angle of illumination. The collected data appear as a 3D plot – the holographic image of the object. We present experimental data showing magnonic holographic images of a low-coercivity Si/Co sample, a high-coercivity sample made of SrFe{sub 12}O{sub 19} and a diamagnetic copper sample. We also present images of the three samples consisting of a different amount of SrFe{sub 12}O{sub 19} powder. The imaging was accomplished on a Y{sub 3}Fe{sub 2}(FeO{sub 4}){sub 3} testbed at room temperature. The obtained data reveal the unique magnonic signatures of the objects. Experimental data is complemented by the results of numerical modeling, which qualitatively explain the characteristic features of the images. Potentially, magnonic holographic imaging may complement existing techniques and be utilized for non-destructive in-situ magnetic object characterization. The fundamental physical limits of this approach are also discussed. - Highlights: • A technique for magnetic microstructure imaging via their interaction with propagating spin waves is proposed. • In this technique, magnetic structures appear as 3D objects. • Several holographic images of magnetic microstructures are presented.

A defect in holographic interpretations of tensor networks

Energy Technology Data Exchange (ETDEWEB)

Czech, Bartłomiej [Institute for Advanced Study,Princeton, NJ 08540 (United States); Nguyen, Phuc H.; Swaminathan, Sivaramakrishnan [Theory Group, Department of Physics and Texas Cosmology Center,The University of Texas at Austin,Austin, TX 78712 (United States)

2017-03-16

We initiate the study of how tensor networks reproduce properties of static holographic space-times, which are not locally pure anti-de Sitter. We consider geometries that are holographically dual to ground states of defect, interface and boundary CFTs and compare them to the structure of the requisite MERA networks predicted by the theory of minimal updates. When the CFT is deformed, certain tensors require updating. On the other hand, even identical tensors can contribute differently to estimates of entanglement entropies. We interpret these facts holographically by associating tensor updates to turning on non-normalizable modes in the bulk. In passing, we also clarify and complement existing arguments in support of the theory of minimal updates, propose a novel ansatz called rayed MERA that applies to a class of generalized interface CFTs, and analyze the kinematic spaces of the thin wall and AdS{sub 3}-Janus geometries.

The CP-odd sector and $θ$ dynamics in holographic QCD

NARCIS (Netherlands)

Arean, Daniel; Iatrakis, Ioannis; Jarvinen, Matti; Kiritsis, Elias

2017-01-01

The holographic model of V-QCD is used to analyze the physics of QCD in the Veneziano large-N limit. An unprecedented analysis of the CP-odd physics is performed going beyond the level of effective field theories. The structure of holographic saddle-points at finite $\\theta$ is determined, as well

The holographic bound in the scalar-tensor and f(R) gravities

International Nuclear Information System (INIS)

Firouzjaee, J.T.

2013-01-01

The holographic bound has been extended to the different theory of gravities such as scalar-tensor gravity and f(R) gravity according to the Noether charge definition of the entropy for a black hole surface. We have introduced some popular examples of the flat FRW cosmology in order to investigate holographic bound in scalar-tensor and f(R) gravity. Using the holographic bound, we put an additional constraint on scalar-tensor gravity and the f(R) gravity parameters. We also discuss the transformation from Jordan frame to Einstein frame. (orig.)

Digital signal processing for He3 proportional counter

International Nuclear Information System (INIS)

Ahmadov, Q.S.; Institute of Radiation Problems, ANAS, Baku

2011-01-01

Full text: Data acquisition systems for nuclear spectroscopy have traditionally been based on systems with analog shaping amplifiers followed by analog-to-digital converters. Recently, however, new systems based on digital signal processing allow us to replace the analog shaping and timing circuitry the numerical algorithms to derive properties of the pulse such as its amplitude. DSP is a fully numerical analysis of the detector pulse signals and this technique demonstrates significant advantages over analog systems in some circumstances. From a mathematical point of view, one can consider the signal evolution from the detector to the ADC as a sequence of transformations that can be described by precisely defined mathematical expressions.Digital signal processing with ADCs has the possibility to utilize further information on the signal pulses from radiation detectors [1] [2]. In the experiment each step of the signal generation in the 3He filled proportional counter was described using digital signal processing techniques (DSP). The electronic system has consisted of a detector, a preamplifier and a digital oscilloscope. The pulses from the detector were digitized using a OTSZS-02 (250USB)-4 digital storage oscilloscope from ZAO R UDNEV-SHILYAYEV . This oscilloscope allowed signal digitization with accuracy of 8 bit(256 levels) and with frequency of up to 5.10''8 samples/s. As a neutron source was used Cf-252.To obtain detector output current pulse I(t) created by the motions of the ions/electrons pairs was written an algorithm which can easily be programmed using modern computer programming languages

Broadband analog to digital conversion with spatial-spectral holography

International Nuclear Information System (INIS)

Babbitt, W. Randall; Neifeld, Mark A.; Merkel, Kristian D.

2007-01-01

A new approach to broadband photonic-assisted analog-to-digital converter (ADC) technology is proposed and analyzed. The core of the device is a spatial spectral holographic (SSH) material, which can directly record the signals of interest in the frequency domain. An SSH-ADC acts as a frequency-domain stretch processor, which leverages the high performance of conventional ADCs by converting high bandwidth input signals to low bandwidth output signals without loss of information. Analysis of a 10 GHz bandwidth SSH-ADC predicts that 10-bit performance can be achieved with currently available materials and components. SSH-ADC technology is scalable to bandwidths over 100 GHz with recently developed SSH materials. While the SSH-ADC is a transient digitizer, the spatial parallelism of SSH materials can be utilized to enable continuous digitization

Broadband analog to digital conversion with spatial-spectral holography

Energy Technology Data Exchange (ETDEWEB)

Babbitt, W. Randall [Spectrum Lab, Montana State University, Bozeman, MT 59717-3510 (United States)]. E-mail: babbitt@physics.montana.edu; Neifeld, Mark A. [Spectrum Lab, Montana State University, Bozeman, MT 59717-3510 (United States); Merkel, Kristian D. [Spectrum Lab, Montana State University, Bozeman, MT 59717-3510 (United States)

2007-11-15

A new approach to broadband photonic-assisted analog-to-digital converter (ADC) technology is proposed and analyzed. The core of the device is a spatial spectral holographic (SSH) material, which can directly record the signals of interest in the frequency domain. An SSH-ADC acts as a frequency-domain stretch processor, which leverages the high performance of conventional ADCs by converting high bandwidth input signals to low bandwidth output signals without loss of information. Analysis of a 10 GHz bandwidth SSH-ADC predicts that 10-bit performance can be achieved with currently available materials and components. SSH-ADC technology is scalable to bandwidths over 100 GHz with recently developed SSH materials. While the SSH-ADC is a transient digitizer, the spatial parallelism of SSH materials can be utilized to enable continuous digitization.

Entanglement from dissipation and holographic interpretation

Science.gov (United States)

Cantcheff, M. Botta; Gadelha, Alexandre L.; Marchioro, Dáfni F. Z.; Nedel, Daniel Luiz

2018-02-01

In this work we study a dissipative field theory where the dissipation process is manifestly related to dynamical entanglement and put it in the holographic context. Such endeavour is realized by further development of a canonical approach to study quantum dissipation, which consists of doubling the degrees of freedom of the original system by defining an auxiliary one. A time dependent entanglement entropy for the vacumm state is calculated and a geometrical interpretation of the auxiliary system and the entropy is given in the context of the AdS/CFT correspondence using the Ryu-Takayanagi formula. We show that the dissipative dynamics is controlled by the entanglement entropy and there are two distinct stages: in the early times the holographic interpretation requires some deviation from classical General Relativity; in the later times the quantum system is described as a wormhole, a solution of the Einstein's equations near to a maximally extended black hole with two asymptotically AdS boundaries. We focus our holographic analysis in this regime, and suggest a mechanism similar to teleportation protocol to exchange (quantum) information between the two CFTs on the boundaries (see Maldacena et al. in Fortschr Phys 65(5):1700034, arXiv:1704.05333 [hep-th], 2017).

Constraining holographic cosmology using Planck data

Science.gov (United States)

Afshordi, Niayesh; Gould, Elizabeth; Skenderis, Kostas

2017-06-01

Holographic cosmology offers a novel framework for describing the very early Universe in which cosmological predictions are expressed in terms of the observables of a three-dimensional quantum field theory (QFT). This framework includes conventional slow-roll inflation, which is described in terms of a strongly coupled QFT, but it also allows for qualitatively new models for the very early Universe, where the dual QFT may be weakly coupled. The new models describe a universe which is nongeometric at early times. While standard slow-roll inflation leads to a (near-) power-law primordial power spectrum, perturbative super-renormalizable QFTs yield a new holographic spectral shape. Here, we compare the two predictions against cosmological observations. We use CosmoMC to determine the best fit parameters, and MultiNest for Bayesian evidence, comparing the likelihoods. We find that the dual QFT should be nonperturbative at the very low multipoles (l ≲30 ), while for higher multipoles (l ≳30 ) the new holographic model, based on perturbative QFT, fits the data just as well as the standard power-law spectrum assumed in Λ CDM cosmology. This finding opens the door to applications of nonperturbative QFT techniques, such as lattice simulations, to observational cosmology on gigaparsec scales and beyond.

Entanglement from dissipation and holographic interpretation

Energy Technology Data Exchange (ETDEWEB)

Cantcheff, M.B. [IFLP-CONICET CC 67, La Plata, Buenos Aires (Argentina); Gadelha, Alexandre L. [Universidade Federal da Bahia, Instituto de Fisica, Salvador, BA (Brazil); Marchioro, Dafni F.Z.; Nedel, Daniel Luiz [Universidade Federal da Integracao Latino-Americana, Instituto Latino-Americano de Ciencias da Vida e da Natureza, Foz do Iguacu, PR (Brazil)

2018-02-15

In this work we study a dissipative field theory where the dissipation process is manifestly related to dynamical entanglement and put it in the holographic context. Such endeavour is realized by further development of a canonical approach to study quantum dissipation, which consists of doubling the degrees of freedom of the original system by defining an auxiliary one. A time dependent entanglement entropy for the vacuum state is calculated and a geometrical interpretation of the auxiliary system and the entropy is given in the context of the AdS/CFT correspondence using the Ryu-Takayanagi formula. We show that the dissipative dynamics is controlled by the entanglement entropy and there are two distinct stages: in the early times the holographic interpretation requires some deviation from classical General Relativity; in the later times the quantum system is described as a wormhole, a solution of the Einstein's equations near to a maximally extended black hole with two asymptotically AdS boundaries. We focus our holographic analysis in this regime, and suggest a mechanism similar to teleportation protocol to exchange (quantum) information between the two CFTs on the boundaries (see Maldacena et al. in Fortschr Phys 65(5):1700034, arXiv:1704.05333 [hep-th], 2017). (orig.)

Phase unwrapping in digital holography based on non-subsampled contourlet transform

Science.gov (United States)

Zhang, Xiaolei; Zhang, Xiangchao; Xu, Min; Zhang, Hao; Jiang, Xiangqian

2018-01-01

In the digital holographic measurement of complex surfaces, phase unwrapping is a critical step for accurate reconstruction. The phases of the complex amplitudes calculated from interferometric holograms are disturbed by speckle noise, thus reliable unwrapping results are difficult to be obtained. Most of existing unwrapping algorithms implement denoising operations first to obtain noise-free phases and then conduct phase unwrapping pixel by pixel. This approach is sensitive to spikes and prone to unreliable results in practice. In this paper, a robust unwrapping algorithm based on the non-subsampled contourlet transform (NSCT) is developed. The multiscale and directional decomposition of NSCT enhances the boundary between adjacent phase levels and henceforth the influence of local noise can be eliminated in the transform domain. The wrapped phase map is segmented into several regions corresponding to different phase levels. Finally, an unwrapped phase map is obtained by elevating the phases of a whole segment instead of individual pixels to avoid unwrapping errors caused by local spikes. This algorithm is suitable for dealing with complex and noisy wavefronts. Its universality and superiority in the digital holographic interferometry have been demonstrated by both numerical analysis and practical experiments.

A single chip pulse processor for nuclear spectroscopy

International Nuclear Information System (INIS)

Hilsenrath, F.; Bakke, J.C.; Voss, H.D.

1985-01-01

A high performance digital pulse processor, integrated into a single gate array microcircuit, has been developed for spaceflight applications. The new approach takes advantage of the latest CMOS high speed A/D flash converters and low-power gated logic arrays. The pulse processor measures pulse height, pulse area and the required timing information (e.g. multi detector coincidence and pulse pile-up detection). The pulse processor features high throughput rate (e.g. 0.5 Mhz for 2 usec gausssian pulses) and improved differential linearity (e.g. + or - 0.2 LSB for a + or - 1 LSB A/D). Because of the parallel digital architecture of the device, the interface is microprocessor bus compatible. A satellite flight application of this module is presented for use in the X-ray imager and high energy particle spectrometers of the PEM experiment on the Upper Atmospheric Research Satellite

Baryon physics in holographic QCD

Directory of Open Access Journals (Sweden)

Alex Pomarol

2009-03-01

Full Text Available In a simple holographic model for QCD in which the Chern–Simons term is incorporated to take into account the QCD chiral anomaly, we show that baryons arise as stable solitons which are the 5D analogs of 4D skyrmions. Contrary to 4D skyrmions and previously considered holographic scenarios, these solitons have sizes larger than the inverse cut-off of the model, and therefore they are predictable within our effective field theory approach. We perform a numerical determination of several static properties of the nucleons and find a satisfactory agreement with data. We also calculate the amplitudes of “anomalous” processes induced by the Chern–Simons term in the meson sector, such as ω→πγ and ω→3π. A combined fit to baryonic and mesonic observables leads to an agreement with experiments within 16%.

Holographic Aspects of a Relativistic Nonconformal Theory

Directory of Open Access Journals (Sweden)

Chanyong Park

2013-01-01

Full Text Available We study a general D-dimensional Schwarzschild-type black brane solution of the Einstein-dilaton theory and derive, by using the holographic renormalization, its thermodynamics consistent with the geometric results. Using the membrane paradigm, we calculate the several hydrodynamic transport coefficients and compare them with the results obtained by the Kubo formula, which shows the self-consistency of the gauge/gravity duality in the relativistic nonconformal theory. In order to understand more about the relativistic non-conformal theory, we further investigate the binding energy, drag force, and holographic entanglement entropy of the relativistic non-conformal theory.

Real-time visualization and analysis of airflow field by use of digital holography

Science.gov (United States)

Di, Jianglei; Wu, Bingjing; Chen, Xin; Liu, Junjiang; Wang, Jun; Zhao, Jianlin

2013-04-01

The measurement and analysis of airflow field is very important in fluid dynamics. For airflow, smoke particles can be added to visually observe the turbulence phenomena by particle tracking technology, but the effect of smoke particles to follow the high speed airflow will reduce the measurement accuracy. In recent years, with the advantage of non-contact, nondestructive, fast and full-field measurement, digital holography has been widely applied in many fields, such as deformation and vibration analysis, particle characterization, refractive index measurement, and so on. In this paper, we present a method to measure the airflow field by use of digital holography. A small wind tunnel model made of acrylic glass is built to control the velocity and direction of airflow. Different shapes of samples such as aircraft wing and cylinder are placed in the wind tunnel model to produce different forms of flow field. With a Mach-Zehnder interferometer setup, a series of digital holograms carrying the information of airflow filed distributions in different states are recorded by CCD camera and corresponding holographic images are numerically reconstructed from the holograms by computer. Then we can conveniently obtain the velocity or pressure information of the airflow deduced from the quantitative phase information of holographic images and visually display the airflow filed and its evolution in the form of a movie. The theory and experiment results show that digital holography is a robust and feasible approach for real-time visualization and analysis of airflow field.

Holographic duality: Stealing dimensions from metals

Science.gov (United States)

Zaanen, Jan

2013-10-01

Although electrically charged black holes seem remote from superconductors and strange metals in the laboratory, they might be intimately related by the holographic dualities discovered in string theory.

Automated red blood cells extraction from holographic images using fully convolutional neural networks

Science.gov (United States)

Yi, Faliu; Moon, Inkyu; Javidi, Bahram

2017-01-01

In this paper, we present two models for automatically extracting red blood cells (RBCs) from RBCs holographic images based on a deep learning fully convolutional neural network (FCN) algorithm. The first model, called FCN-1, only uses the FCN algorithm to carry out RBCs prediction, whereas the second model, called FCN-2, combines the FCN approach with the marker-controlled watershed transform segmentation scheme to achieve RBCs extraction. Both models achieve good segmentation accuracy. In addition, the second model has much better performance in terms of cell separation than traditional segmentation methods. In the proposed methods, the RBCs phase images are first numerically reconstructed from RBCs holograms recorded with off-axis digital holographic microscopy. Then, some RBCs phase images are manually segmented and used as training data to fine-tune the FCN. Finally, each pixel in new input RBCs phase images is predicted into either foreground or background using the trained FCN models. The RBCs prediction result from the first model is the final segmentation result, whereas the result from the second model is used as the internal markers of the marker-controlled transform algorithm for further segmentation. Experimental results show that the given schemes can automatically extract RBCs from RBCs phase images and much better RBCs separation results are obtained when the FCN technique is combined with the marker-controlled watershed segmentation algorithm. PMID:29082078

Holographic diffuser by use of a silver halide sensitized gelatin process

Science.gov (United States)

Kim, Sun Il; Choi, Yoon Sun; Ham, Yong Nam; Park, Chong Yun; Kim, Jong Man

2003-05-01

Diffusers play an important role in liquid-crystal display (LCD) application as a beam-shaping device, a brightness homogenizer, a light-scattering device, and an imaging screen. The transmittance and diffusing angle of the diffusers are the critical aspects for the applications to the LCD. The holographic diffusers by use of various processing methods have been investigated. The diffusing characteristics of different diffusing materials and processing methods have been evaluated and compared. The micro-structures of holographic diffusers have been investigated by use of using scanning electron microscopy. The holographic diffusers by use of the silver halide sensitized gelatin (SHSG) method have the structural merits for the improvement of the quality of diffusers. The features of holographic diffuser were exceptional in terms of transmittance and diffusing angle. The replication method by use of the SHSG process can be directly used for the manufacturing of diffusers for the display application.

Conformal symmetry and holographic cosmology

NARCIS (Netherlands)

Bzowski, A.W.

2013-01-01

This thesis presents a novel approach to cosmology using gauge/gravity duality. Analysis of the implications of conformal invariance in field theories leads to quantitative cosmological predictions which are in agreement with current data. Furthermore, holographic cosmology extends the theory of