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Sample records for extraordinary optical transmission

  1. Some Advances in the Circuit Modeling of Extraordinary Optical Transmission

    Directory of Open Access Journals (Sweden)

    F. Medina

    2009-06-01

    Full Text Available The phenomenon of extraordinary optical transmission (EOT through electrically small holes perforated on opaque metal screens has been a hot topic in the optics community for more than one decade. This experimentally observed frequency-selective enhanced transmission of electromagnetic power through holes, for which classical Bethe's theory predicts very poor transmission, later attracted the attention of engineers working on microwave engineering or applied electromagnetics. Extraordinary transmission was first linked to the plasma-like behavior of metals at optical frequencies. However, the primary role played by the periodicity of the distribution of holes was soon made evident, in such a way that extraordinary transmission was disconnected from the particular behavior of metals at optical frequencies. Indeed, the same phenomenon has been observed in the microwave and millimeter wave regime, for instance. Nowadays, the most commonly accepted theory explains EOT in terms of the interaction of the impinging plane wave with the surface plasmon-polariton-Bloch waves (SPP-Bloch supported by the periodically perforated plate. The authors of this paper have recently proposed an alternative model whose details will be briefly summarized here. A parametric study of the predictions of the model and some new potential extensions will be reported to provide additional insight.

  2. Extraordinary optical transmission through nonlocal holey metal films

    DEFF Research Database (Denmark)

    David, Christin; Christensen, Johan

    2017-01-01

    We investigate nonlocal electrodynamics based on the generalized hydrodynamic approach including electron diffusion in holey gold films, showing extraordinary optical transmission (EOT). Dramatic changes with respect to the local approximation for rather large film thicknesses t less than...... or similar to 100 nm impact both reflectance and absorbance at normal incidence. Beyond the familiar resonance blueshift with the decreasing film thickness, the interference of longitudinal pressure waves in the holey structure generates an unexpected oscillatory response with geometrical parameters...

  3. Enhanced extraordinary optical transmission (EOT) through arrays of bridged nanohole pairs and their sensing applications

    KAUST Repository

    Yue, Weisheng; Wang, Zhihong; Yang, Yang; Li, Jingqi; Wu, Ying; Chen, Longqing; Ooi, Boon S.; Wang, Xianbin; Zhang, Xixiang

    2014-01-01

    Extraordinary optical transmission (EOT) through arrays of gold nanoholes was studied with light across the visible to the near-infrared spectrum. The EOT effect was found to be improved by bridging pairs of nanoholes due to the concentration

  4. Ultrastrong extraordinary transmission and reflection in PT-symmetric Thue-Morse optical waveguide networks.

    Science.gov (United States)

    Wu, Jiaye; Yang, Xiangbo

    2017-10-30

    In this paper, we construct a 1D PT-symmetric Thue-Morse aperiodic optical waveguide network (PTSTMAOWN) and mainly investigate the ultrastrong extraordinary transmission and reflection. We propose an approach to study the photonic modes and solve the problem of calculating photonic modes distributions in aperiodic networks due to the lack of dispersion functions and find that in a PTSTMAOWN there exist more photonic modes and more spontaneous PT-symmetric breaking points, which are quite different from other reported PT-symmetric optical systems. Additionally, we develop a method to sort spontaneous PT-symmetric breaking point zones to seek the strongest extraordinary point and obtain that at this point the strongest extraordinary transmission and reflection arrive at 2.96316 × 10 5 and 1.32761 × 10 5 , respectively, due to the PT-symmetric coupling resonance and the special symmetry pattern of TM networks. These enormous gains are several orders of magnitude larger than the previous results. This optical system may possess potential in designing optical amplifier, optical logic elements in photon computers and ultrasensitive optical switches with ultrahigh monochromatity.

  5. Enhanced extraordinary optical transmission (EOT) through arrays of bridged nanohole pairs and their sensing applications

    KAUST Repository

    Yue, Weisheng

    2014-01-01

    Extraordinary optical transmission (EOT) through arrays of gold nanoholes was studied with light across the visible to the near-infrared spectrum. The EOT effect was found to be improved by bridging pairs of nanoholes due to the concentration of the electromagnetic field in the slit between the holes. The geometrical shape and separation of the holes in these pairs of nanoholes affected the intensity of the transmission and the wavelength of resonance. Changing the geometrical shapes of these nanohole pairs from triangles to circles to squares leads to increased transmission intensity as well as red-shifting resonance wavelengths. The performance of bridged nanohole pairs as a plasmonic sensor was investigated. The bridged nanohole pairs were able to distinguish methanol, olive oil and microscope immersion oil for the different surface plasmon resonance in transmission spectra. Numerical simulation results were in agreement with experimental observations. © 2014 the Partner Organisations.

  6. Quasi-cylindrical wave contribution in experiments on extraordinary optical transmission.

    Science.gov (United States)

    van Beijnum, Frerik; Rétif, Chris; Smiet, Chris B; Liu, Haitao; Lalanne, Philippe; van Exter, Martin P

    2012-12-20

    A metal film perforated by a regular array of subwavelength holes shows unexpectedly large transmission at particular wavelengths, a phenomenon known as the extraordinary optical transmission (EOT) of metal hole arrays. EOT was first attributed to surface plasmon polaritons, stimulating a renewed interest in plasmonics and metallic surfaces with subwavelength features. Experiments soon revealed that the field diffracted at a hole or slit is not a surface plasmon polariton mode alone. Further theoretical analysis predicted that the extra contribution, from quasi-cylindrical waves, also affects EOT. Here we report the experimental demonstration of the relative importance of surface plasmon polaritons and quasi-cylindrical waves in EOT by considering hole arrays of different hole densities. From the measured transmission spectra, we determine microscopic scattering parameters which allow us to show that quasi-cylindrical waves affect EOT only for high densities, when the hole spacing is roughly one wavelength. Apart from providing a deeper understanding of EOT, the determination of microscopic scattering parameters from the measurement of macroscopic optical properties paves the way to novel design strategies.

  7. Gold Nanohole Array with Sub-1 nm Roughness by Annealing for Sensitivity Enhancement of Extraordinary Optical Transmission Biosensor

    Science.gov (United States)

    Zhang, Jian; Irannejad, Mehrdad; Yavuz, Mustafa; Cui, Bo

    2015-05-01

    Nanofabrication technology plays an important role in the performance of surface plasmonic devices such as extraordinary optical transmission (EOT) sensor. In this work, a double liftoff process was developed to fabricate a series of nanohole arrays of a hole diameter between 150 and 235 nm and a period of 500 nm in a 100-nm-thick gold film on a silica substrate. To improve the surface quality of the gold film, thermal annealing was conducted, by which an ultra-smooth gold film with root-mean-square (RMS) roughness of sub-1 nm was achieved, accompanied with a hole diameter shrinkage. The surface sensitivity of the nanohole arrays was measured using a monolayer of 16-mercaptohexadecanoic acid (16-MHA) molecule, and the surface sensitivity was increased by 2.5 to 3 times upon annealing the extraordinary optical transmission (EOT) sensor.

  8. Management of light absorption in extraordinary optical transmission based ultra-thin-film tandem solar cells

    International Nuclear Information System (INIS)

    Mashooq, Kishwar; Talukder, Muhammad Anisuzzaman

    2016-01-01

    Although ultra-thin-film solar cells can be attractive in reducing the cost, they suffer from low absorption as the thickness of the active layer is usually much smaller than the wavelength of incident light. Different nano-photonic techniques, including plasmonic structures, are being explored to increase the light absorption in ultra-thin-film solar cells. More than one layer of active materials with different energy bandgaps can be used in tandem to increase the light absorption as well. However, due to different amount of light absorption in different active layers, photo-generated currents in different active layers will not be the same. The current mismatch between the tandem layers makes them ineffective in increasing the efficiency. In this work, we investigate the light absorption properties of tandem solar cells with two ultra-thin active layers working as two subcells and a metal layer with periodically perforated holes in-between the two subcells. While the metal layer helps to overcome the current mismatch, the periodic holes increase the absorption of incident light by helping extraordinary optical transmission of the incident light from the top to the bottom subcell, and by coupling the incident light to plasmonic and photonic modes within ultra-thin active layers. We extensively study the effects of the geometry of holes in the intermediate metal layer on the light absorption properties of tandem solar cells with ultra-thin active layers. We also study how different metals in the intermediate layer affect the light absorption; how the geometry of holes in the intermediate layer affects the absorption when the active layer materials are changed; and how the intermediate metal layer affects the collection of photo-generated electron-hole pairs at the terminals. We find that in a solar cell with 6,6-phenyl C61-butyric acid methyl ester top subcell and copper indium gallium selenide bottom subcell, if the periodic holes in the metal layer are square or

  9. Management of light absorption in extraordinary optical transmission based ultra-thin-film tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mashooq, Kishwar; Talukder, Muhammad Anisuzzaman, E-mail: anis@eee.buet.ac.bd [Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1205 (Bangladesh)

    2016-05-21

    Although ultra-thin-film solar cells can be attractive in reducing the cost, they suffer from low absorption as the thickness of the active layer is usually much smaller than the wavelength of incident light. Different nano-photonic techniques, including plasmonic structures, are being explored to increase the light absorption in ultra-thin-film solar cells. More than one layer of active materials with different energy bandgaps can be used in tandem to increase the light absorption as well. However, due to different amount of light absorption in different active layers, photo-generated currents in different active layers will not be the same. The current mismatch between the tandem layers makes them ineffective in increasing the efficiency. In this work, we investigate the light absorption properties of tandem solar cells with two ultra-thin active layers working as two subcells and a metal layer with periodically perforated holes in-between the two subcells. While the metal layer helps to overcome the current mismatch, the periodic holes increase the absorption of incident light by helping extraordinary optical transmission of the incident light from the top to the bottom subcell, and by coupling the incident light to plasmonic and photonic modes within ultra-thin active layers. We extensively study the effects of the geometry of holes in the intermediate metal layer on the light absorption properties of tandem solar cells with ultra-thin active layers. We also study how different metals in the intermediate layer affect the light absorption; how the geometry of holes in the intermediate layer affects the absorption when the active layer materials are changed; and how the intermediate metal layer affects the collection of photo-generated electron-hole pairs at the terminals. We find that in a solar cell with 6,6-phenyl C61-butyric acid methyl ester top subcell and copper indium gallium selenide bottom subcell, if the periodic holes in the metal layer are square or

  10. Extraordinary optical transmission with tapered slits: effect of higher diffraction and slit resonance orders

    DEFF Research Database (Denmark)

    Sondergaard, T.; Bozhevolnyi, S. I.; Beermann, J.

    2012-01-01

    Transmission through thin metal films with a periodic arrangement of tapered slits is considered. Transmission maps covering a wide range of periods, film thicknesses, and taper angles are presented. The maps show resonant transmission when fundamental and higher-order slit resonances are excited...... to be in the range of 6 degrees-10 degrees. Both theory and experiments show split-peak spectra and shifted-peak spectra due to interference between a slit resonance and Rayleigh-Wood anomalies. (C) 2011 Optical Society of America...

  11. Enhancement of magneto-optical Faraday effects and extraordinary optical transmission in a tri-layer structure with rectangular annular arrays.

    Science.gov (United States)

    Lei, Chengxin; Chen, Leyi; Tang, Zhixiong; Li, Daoyong; Cheng, Zhenzhi; Tang, Shaolong; Du, Youwei

    2016-02-15

    The properties of optics and magneto-optical Faraday effects in a metal-dielectric tri-layer structure with subwavelength rectangular annular arrays are investigated. It is noteworthy that we obtained the strongly enhanced Faraday rotation of the desired sign along with high transmittance by optimizing the parameters of the nanostructure in the visible spectral ranges. In this system, we obtained two extraordinary optical transmission (EOT) resonant peaks with enhanced Faraday rotations, whose signs are opposite, which may provide the possibility of designing multi-channel magneto-optical devices. Study results show that the maximum of the figure of merit (FOM) of the structure can be obtained between two EOT resonant peaks accompanied by an enhanced Faraday rotation. The positions of the maximum value of the FOM and resonant peaks of transmission along with a large Faraday rotation can be tailored by simply adjusting the geometric parameters of our models. These research findings are of great importance for future applications of magneto-optical devices.

  12. Extraordinary acoustic transmission mediated by Helmholtz resonators

    Directory of Open Access Journals (Sweden)

    Vijay Koju

    2014-07-01

    Full Text Available We demonstrate perfect transmission of sound through a rigid barrier embedded with Helmholtz resonators. The resonators are confined within a waveguide and they are oriented such that one neck protrudes onto each side of the barrier. Perfect sound transmission occurs even though the open area of the necks is less than 3% of the barrier area. Maximum transmission occurs at the resonant frequency of the Helmholtz resonator. Because the dimensions of the Helmholtz resonators are much smaller than the resonant wavelength, the transmission is independent of the direction of sound on the barrier and of the relative placement of the necks. Further, we show that the transmitted sound experiences a continuous phase transition of π radians as a function of frequency through resonance. In simulations of adjacent resonators with slightly offset resonance frequencies, the phase difference leads to destructive interference. By expanding the simulation to a linear array of tuned Helmholtz resonators we show that it is possible to create an acoustic lens. The ability of Helmholtz resonator arrays to manipulate the phase of a plane acoustic wave enables a new class of sonic beam-forming devices analogous to diffractive optics.

  13. Quasioptical devices based on extraordinary transmission at THz

    Science.gov (United States)

    Beruete, Miguel

    2016-04-01

    In this work I will present our latest advances in components developed from extraordinary transmission concepts operating at terahertz (THz) frequencies. First, a structure exhibiting two different extraordinary transmission resonances depending on the polarization of the incident wave will be shown. The peaks of transmission appear at approximately 2 and 2.5 THz for vertical and horizontal polarization, respectively, with a transmittance above 60% in both cases. Later on, a meandering line structure able to tune the extraordinary transmission resonance will be discussed. The operation frequency in this case is between 9 and 17 THz. A self-complementary polarizer will be then presented, with a high polarization purity. The fundamentals of this device based on the Babinet's principle will be discussed in depth. Finally, all these structures will be combined together to produce a dual-band Quarter Wave Plate able to convert a linear polarization at the input in a circular polarization at the output at two different bands, 1 and 2.2. THz. Some final words regarding the potential of extraordinary transmission for sensing applications will close the contribution.

  14. Experimental realization of extraordinary acoustic transmission using Helmholtz resonators

    Directory of Open Access Journals (Sweden)

    Brian C. Crow

    2015-02-01

    Full Text Available The phenomenon of extraordinary acoustic transmission through a solid barrier with an embedded Helmholtz resonator (HR is demonstrated. The Helmholtz resonator consists of an embedded cavity and two necks that protrude, one on each side of the barrier. Extraordinary transmission occurs for a narrow spectral range encompassing the resonant frequency of the Helmholtz resonator. We show that an amplitude transmission of 97.5% is achieved through a resonator whose neck creates an open area of 6.25% of the total barrier area. In addition to the enhanced transmission, we show that there is a smooth, continuous phase transition in the transmitted sound as a function of frequency. The frequency dependent phase transition is used to experimentally realize slow wave propagation for a narrow-band Gaussian wave packet centered at the maximum transmission frequency. The use of parallel pairs of Helmholtz resonators tuned to different resonant frequencies is experimentally explored as a means of increasing the transmission bandwidth. These experiments show that because of the phase transition, there is always a frequency between the two Helmholtz resonant frequencies at which destructive interference occurs whether the resonances are close or far apart. Finally, we explain how the phase transition associated with Helmholtz-resonator-mediated extraordinary acoustic transmission can be exploited to produce diffractive acoustic components including sub-wavelength thickness acoustic lenses.

  15. Anomalous Faraday effect of a system with extraordinary optical transmittance.

    Science.gov (United States)

    Khanikaev, Alexander B; Baryshev, Alexander V; Fedyanin, Andrey A; Granovsky, Alexander B; Inoue, Mitsuteru

    2007-05-28

    It is shown theoretically that the Faraday rotation becomes anomalously large and exhibits extraordinary behavior near the frequencies of the extraordinary optical transmittance through optically thick perforated metal film with holes filled with a magneto-optically active material. This phenomenon is explained as result of strong confinement of the evanescent electromagnetic field within magnetic material, which occurs due to excitation of the coupled plasmon-polaritons on the opposite surfaces of the film.

  16. An extraordinary transmission analogue for enhancing microwave antenna performance

    Directory of Open Access Journals (Sweden)

    Sarin V. Pushpakaran

    2015-10-01

    Full Text Available The theory of diffraction limit proposed by H.A Bethe limits the total power transfer through a subwavelength hole. Researchers all over the world have gone through different techniques for boosting the transmission through subwavelength holes resulting in the Extraordinary Transmission (EOT behavior. We examine computationally and experimentally the concept of EOT nature in the microwave range for enhancing radiation performance of a stacked dipole antenna working in the S band. It is shown that the front to back ratio of the antenna is considerably enhanced without affecting the impedance matching performance of the design. The computational analysis based on Finite Difference Time Domain (FDTD method reveals that the excitation of Fabry-Perot resonant modes on the slots is responsible for performance enhancement.

  17. Direct measurements of the extraordinary optical\

    Czech Academy of Sciences Publication Activity Database

    Antognozzi, M.; Bermingham, C.R.; Harniman, R.L.; Simpson, Stephen Hugh; Senior, J.; Hayward, I.R.; Hoerber, H.; Dennis, M.R.; Bekshaev, A.Y.; Bliokh, K.Y.; Nori, F.

    2016-01-01

    Roč. 12, č. 8 (2016), s. 731-735 ISSN 1745-2473 R&D Projects: GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : radiation-pressure * angular-momentum * microscopy Subject RIV: BH - Optics, Masers, Lasers Impact factor: 22.806, year: 2016

  18. New approach for extraordinary transmission through an array of subwavelength apertures using thin ENNZ metamaterial liners.

    Science.gov (United States)

    Baladi, Elham; Pollock, Justin G; Iyer, Ashwin K

    2015-08-10

    Extraordinary transmission (ET) through a periodic array of subwavelength apertures on a perfect metallic screen has been studied extensively in recent years, and has largely been attributed to diffraction effects, for which the periodicity of the apertures, rather than their dimensions, dominates the response. The transmission properties of the apertures at resonance, on the other hand, are not typically considered 'extraordinary' because they may be explained using more conventional aperture-theoretical mechanisms. This work describes a novel approach for achieving ET in which subwavelength apertures are made to resonate by lining them using thin, epsilon-negative and near-zero (ENNZ) metamaterials. The use of ENNZ metamaterials has recently proven successful in miniaturizing circular waveguides by strongly reducing their natural cutoff frequencies, and the theory is adapted here for the design of subwavelength apertures in a metallic screen. We present simulations and proof-of-concept measurements at microwave frequencies that demonstrate ET for apertures measuring one-quarter of a wavelength in diameter and suggest the potential for even more dramatic miniaturization simply by engineering the ENNZ metamaterial dispersion. The results exhibit a fano-like profile whose frequency varies with the properties of the metamaterial liner, but is independent of period. It is suggested that similar behaviour can be obtained at optical frequencies, where ENNZ metamaterials may be realized using appropriately arranged chains of plasmonic nanoparticles.

  19. Extraordinary Effects in Quasi-Periodic Gold Nanocavities: Enhanced Transmission and Polarization Control of Cavity Modes.

    Science.gov (United States)

    Dhama, Rakesh; Caligiuri, Vincenzo; Petti, Lucia; Rashed, Alireza R; Rippa, Massimo; Lento, Raffaella; Termine, Roberto; Caglayan, Humeyra; De Luca, Antonio

    2018-01-23

    Plasmonic quasi-periodic structures are well-known to exhibit several surprising phenomena with respect to their periodic counterparts, due to their long-range order and higher rotational symmetry. Thanks to their specific geometrical arrangement, plasmonic quasi-crystals offer unique possibilities in tailoring the coupling and propagation of surface plasmons through their lattice, a scenario in which a plethora of fascinating phenomena can take place. In this paper we investigate the extraordinary transmission phenomenon occurring in specifically patterned Thue-Morse nanocavities, demonstrating noticeable enhanced transmission, directly revealed by near-field optical experiments, performed by means of a scanning near-field optical microscope (SNOM). SNOM further provides an intuitive picture of confined plasmon modes inside the nanocavities and confirms that localization of plasmon modes is based on size and depth of nanocavities, while cross talk between close cavities via propagating plasmons holds the polarization response of patterned quasi-crystals. Our performed numerical simulations are in good agreement with the experimental results. Thus, the control on cavity size and incident polarization can be used to alter the intensity and spatial properties of confined cavity modes in such structures, which can be exploited in order to design a plasmonic device with customized optical properties and desired functionalities, to be used for several applications in quantum plasmonics.

  20. Optimization of extraordinary optical absorption in plasmonic and dielectric structures

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard; Sigmund, Ole

    2013-01-01

    Extraordinary optical absorption (EOA) can be obtained by plasmonic surface structuring. However, studies that compare the performance of these plasmonic devices with similar structured dielectric devices are rarely found in the literature. In this work we show different methods to enhance the EOA...... by optimizing the geometry of the surface structuring for both plasmonic and dielectric devices, and the optimized performances are compared. Two different problem types with periodic structures are considered. The first case shows that strips of silicon on a surface can increase the absorption in an underlying...... it is important to compare the absorption performance of plasmonic devices with similarly structured dielectric devices in order to find the best possible solution....

  1. Extraordinary acoustic transmission through annuluses in air and its applications in acoustic beam splitter and concentrator

    International Nuclear Information System (INIS)

    Ge, Yong; Liu, Shu-sen; Yuan, Shou-qi; Xia, Jian-ping; Guan, Yi-jun; Sun, Hong-xiang; Zhang, Shu-yi

    2016-01-01

    We report an extraordinary acoustic transmission through two layer annuluses made of metal cylinders in air both numerically and experimentally. The effect arises from the enhancement and reconstruction of the incident source induced by different Mie-resonance modes of the annuluses. The proposed system takes advantages of the consistency in the waveform between the input and output waves, the high amplitude amplification of output waves, and the easy adjustment of structure. More interestingly, we investigate the applications of the extraordinary acoustic transmission in the acoustic beam splitter and acoustic concentrator. Our finding should have an impact on ultrasonic applications.

  2. Optical analog transmission device

    International Nuclear Information System (INIS)

    Ikawa, Shinji.

    1994-01-01

    The present invention concerns a device such as electro-optical conversion elements, optoelectric-electric elements and optical transmission channel, not undergoing deleterious effects on the efficiency of conversion and transmission due to temperature, and aging change. That is, a sine wave superposing means superposes, on a detector signal to be transmitted, a sine-wave signal having a predetermined amplitude and at a frequency lower than that of the detector signal. An optoelectric conversion means converts the electric signal as the signal of the sine-wave signal superposing means into an optical signal and outputs the same to an optical transmitting channel. The optoelectric conversion means converts the transmitted signal to an electric signal. A discriminating means discriminates the electric signal into a detector signal and a sine-wave signal. A calculating means calculates an optical transmitting efficiency of the transmitting channel based on the amplitude of the discriminated sine-wave signal. A processing means compensates an amplitude value of the detector signals discriminated by the discriminating means based on the optical transmission efficiency. As a result, an optical analog transmission device can be attained, which conducts optical transmission at a high accuracy without undergoing the defective effects of the optical transmission efficiency. (I.S.)

  3. Electromagnetic response of extraordinary transmission plates inspired on Babinet’s principle

    OpenAIRE

    Navarro Cía, Miguel; Beruete Díaz, Miguel; Sorolla Ayza, Mario

    2011-01-01

    This chapter is devoted to polarization effects arisen from perforated metallic plates exhibiting extraordinary transmission (ET). Setting aside the state-of-the-art of perforated metallic plates, we show that by applying Babinet’s principle, subwavelength hole arrays (SHAs) arranged in rectangular lattice can further enhance its potential polarization response. Different perspectives are brought about to describe and understand the particular behaviour of self-complementarines...

  4. Extraordinary mid-infrared transmission of subwavelength holes in gold films

    KAUST Repository

    Yue, Weisheng; Wang, Zhihong; Yang, Yang; Chen, Longqing; Syed, Ahad A.; Wang, Xianbin

    2014-01-01

    Gold (Au) nanoholes are fabricated with electron-beam lithography and used for the investigation of extraordinary transmission in mid-infrared regime. Transmission properties of the nanoholes are studied as the dependence on hole-size. Transmittance spectra are characterized by Fourier transform infrared spectroscopy (FTIR) and enhanced transmittance through the subwavelength holes is observed. The transmission spectra exhibit well-defined maximum and minimum of which the position are determined by the lattice of the hole array. The hole-size primarily influence the transmission intensity and bandwidth of the resonance peak. With an increase of hole-size, while keep lattice constant fixed, the intensity of the resonance peak and the bandwidth increases, which are due to the localized surface plasmons. Numerical simulation for the transmission through the subwavelength holes is performed and the simulated results agree with the experimental observations. Copyright © 2014 American Scientific Publishers.

  5. Extraordinary mid-infrared transmission of subwavelength holes in gold films

    KAUST Repository

    Yue, Weisheng

    2014-04-01

    Gold (Au) nanoholes are fabricated with electron-beam lithography and used for the investigation of extraordinary transmission in mid-infrared regime. Transmission properties of the nanoholes are studied as the dependence on hole-size. Transmittance spectra are characterized by Fourier transform infrared spectroscopy (FTIR) and enhanced transmittance through the subwavelength holes is observed. The transmission spectra exhibit well-defined maximum and minimum of which the position are determined by the lattice of the hole array. The hole-size primarily influence the transmission intensity and bandwidth of the resonance peak. With an increase of hole-size, while keep lattice constant fixed, the intensity of the resonance peak and the bandwidth increases, which are due to the localized surface plasmons. Numerical simulation for the transmission through the subwavelength holes is performed and the simulated results agree with the experimental observations. Copyright © 2014 American Scientific Publishers.

  6. Manipulation of extraordinary acoustic transmission by a tunable bull's eye structure

    International Nuclear Information System (INIS)

    Wang Ji-Wei; Cheng Ying; Liu Xiao-Jun

    2014-01-01

    Extraordinary acoustic transmission (EAT) has been investigated in a tunable bull's eye structure. We demonstrate that the transmission coefficient of acoustic waves can be modulated by a grating structure. When the grating is located at a distance of 0.5 mm from the base plate, the acoustic transmission shows an 8.77-fold enhancement compared to that by using a traditional bull's eye structure. When the distance increases to 1.5 mm, the transmission approaches zero, indicating a total reflection. Thus, we can make an efficient modulation of acoustic transmission from 0 to 877%. The EAT effects have been ascribed to the coupling of structure-induced resonance with the diffractive wave and the waveguide modes, as well as the Fabry-Perot resonances. As a potential application, the modulation of far-field collimation is illustrated in the proposed bull's eye structure. (rapid communication)

  7. Extraordinary light transmission through opaque thin metal film with subwavelength holes blocked by metal disks.

    Science.gov (United States)

    Li, Wen-Di; Hu, Jonathan; Chou, Stephen Y

    2011-10-10

    We observed that when subwavelength-sized holes in an optically opaque metal film are completely covered by opaque metal disks larger than the holes, the light transmission through the holes is not reduced, but rather enhanced. Particularly we report (i) the observation of light transmission through the holes blocked by the metal disks up to 70% larger than the unblocked holes; (ii) the observation of tuning the light transmission by varying the coupling strength between the blocking disks and the hole array, or by changing the size of the disks and holes; (iii) the observation and simulation that the metal disk blocker can improve light coupling from free space to a subwavelength hole; and (iv) the simulation that shows the light transmission through subwavelength holes can be enhanced, even though the gap between the disk and the metal film is partially connected with a metal. We believe these finding should have broad and significant impacts and applications to optical systems in many fields.

  8. Extraordinary electromagnetic transmission by antenna arrays and frequency selective surfaces having compound unit cells with dissimilar elements

    Energy Technology Data Exchange (ETDEWEB)

    Loui, Hung; Strassner, II, Bernd H.

    2018-03-20

    The various embodiments presented herein relate to extraordinary electromagnetic transmission (EEMT) to enable multiple inefficient (un-matched) but coupled radiators and/or apertures to radiate and/or pass electromagnetic waves efficiently. EEMT can be utilized such that signal transmission from a plurality of antennas and/or apertures occurs at a transmission frequency different to transmission frequencies of the individual antennas and/or aperture elements. The plurality of antennas/apertures can comprise first antenna/aperture having a first radiating area and material(s) and second antenna/aperture having a second radiating area and material(s), whereby the first radiating/aperture area and second radiating/aperture area can be co-located in a periodic compound unit cell. Owing to mutual coupling between the respective antennas/apertures in their arrayed configuration, the transmission frequency of the array can be shifted from the transmission frequencies of the individual elements. EEMT can be utilized for an array of evanescent of inefficient radiators connected to a transmission line(s).

  9. Transmission in Optically Transparent Core Networks

    Science.gov (United States)

    Kilper, Dan; Jensen, Rich; Petermann, Klaus; Karasek, Miroslav

    2007-03-01

    Call for Papers: Transmission in Optically Transparent Core Networks Guest Feature Editors Dan Kilper and Rich Jensen, Coordinating Associate Editors Klaus Petermann and Miroslav Karasek, Guest Feature Editors Submission deadline: 15 June 2007 Optically transparent networks in which optical transport signals are routed uninterrupted through multiple nodes have long been viewed as an important evolutionary step in fiber optic communications. More than a decade of research and development on transparent network technologies together with the requisite traffic growth has culminated in the recent deployment of commercial optically transparent systems. Although many of the traditional research goals of optical transmission remain important, optical transparency introduces new challenges. Greater emphasis is placed on system efficiency and control. The goal of minimizing signal terminations, which has been pursued through increasing reach and channel capacity, also can be realized through wavelength routing techniques. Rather than bounding system operation by rigid engineering rules, the physical layer is controlled and managed by automation tools. Many static signal impairments become dynamic due to network reconfiguration and transient fault events. Recently new directions in transmission research have emerged to address transparent networking problems. This special issue of the Journal of Optical Networking will examine the technologies and theory underpinning transmission in optically transparent core networks, including both metropolitan and long haul systems. Scope of Submission The special issue editors are soliciting high-quality original research papers related to transmission in optically transparent core networks. Although this does not include edge networks such as access or enterprise networks, core networks that have access capabilities will be considered in scope as will topics related to the interworking between core and edge networks. The core network

  10. Optoelectronic line transmission an introduction to fibre optics

    CERN Document Server

    Tricker, Raymond L

    2013-01-01

    Optoelectronic Line Transmission: An Introduction to Fibre Optics presents a basic introduction as well as a background reference manual on fiber optic transmission. The book discusses the basic principles of optical line transmission; the advantages and disadvantages of optical fibers and optoelectronic signalling; the practical applications of optoelectronics; and the future of optoelectronics. The text also describes the theories of optical line transmission; fibers and cables for optical transmission; transmitters including light-emitting diodes and lasers; and receivers including photodi

  11. Environmental effects on underwater optical transmission

    Science.gov (United States)

    Chu, Peter C.; Breshears, Brian F.; Cullen, Alexander J.; Hammerer, Ross F.; Martinez, Ramon P.; Phung, Thai Q.; Margolina, Tetyana; Fan, Chenwu

    2017-05-01

    Optical communication/detection systems have potential to get around some limitations of current acoustic communications and detection systems especially increased fleet and port security in noisy littoral waters. Identification of environmental effects on underwater optical transmission is the key to the success of using optics for underwater communication and detection. This paper is to answer the question "What are the transfer and correlation functions that relate measurements of hydrographic to optical parameters?" Hydrographic and optical data have been collected from the Naval Oceanographic Office survey ships with the High Intake Defined Excitation (HIDEX) photometer and sea gliders with optical back scattering sensor in various Navy interested areas such as the Arabian Gulf, Gulf of Oman, east Asian marginal seas, and Adriatic Sea. The data include temperature, salinity, bioluminescence, chlorophyll-a fluorescence, transmissivity at two different wavelengths (TRed at 670 nm, TBlue at 490 nm), and back scattering coefficient (bRed at 700 nm, bBlue at 470 nm). Transfer and correlation functions between the hydrographic and optical parameters are obtained. Bioluminescence and fluorescence maxima, transmissivity minimum with their corresponding depths, red and blue laser beam peak attenuation coefficients are identified from the optical profiles. Evident correlations are found between the ocean mixed layer depth and the blue and red laser beam peak attenuation coefficients, bioluminescence and fluorescence maxima in the Adriatic Sea, Arabian Gulf, Gulf of Oman, and Philippine Sea. Based on the observational data, an effective algorithm is recommended for solving the radiative transfer equation (RTE) for predicting underwater laser radiance.

  12. Spectrally efficient polymer optical fiber transmission

    Science.gov (United States)

    Randel, Sebastian; Bunge, Christian-Alexander

    2011-01-01

    The step-index polymer optical fiber (SI-POF) is an attractive transmission medium for high speed communication links in automotive infotainment networks, in industrial automation, and in home networks. Growing demands for quality of service, e.g., for IPTV distribution in homes and for Ethernet based industrial control networks will necessitate Gigabit speeds in the near future. We present an overview on recent advances in the design of spectrally efficient and robust Gigabit-over-SI-POF transmission systems.

  13. All optical OFDM transmission for passive optical networks

    Science.gov (United States)

    Kachare, Nitin; Ashik T., J.; Bai, K. Kalyani; Kumar, D. Sriram

    2017-06-01

    This paper demonstrates the idea of data transmission at a very higher rate (Tbits/s) through optical fibers in a passive optical network using the most efficient data transmission technique widely used in wireless communication that is orthogonal frequency division multiplexing. With an increase in internet users, data traffic has also increased significantly and the current dense wavelength division multiplexing (DWDM) systems may not support the next generation passive optical networks (PONs) requirements. The approach discussed in this paper allows to increase the downstream data rate per user and extend the standard single-mode fiber reach for future long-haul applications. All-optical OFDM is a promising solution for terabit per second capable single wavelength transmission, with high spectral efficiency and high tolerance to chromatic dispersion.

  14. Extraordinary Tales

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 10. Extraordinary Tales: Parasites Hijacking the Minds of Hosts. Felix Bast. General Article Volume 20 Issue 10 October 2015 pp 893-902. Fulltext. Click here to view fulltext PDF. Permanent link:

  15. Radiation effects on optical data transmission systems

    International Nuclear Information System (INIS)

    Leskovar, B.

    1989-01-01

    The state of the art of optical transmitters, low loss fiber waveguides and receivers in both steady state and pulsed radiation environments is reviewed and summarized. Emphasis is placed on the effects of irradiation on the performance of light emitting and laser diodes, optical fiber waveguides and photodiodes. The influence of radiation-induced attenuation of optical fibers due to total dose, dose rate, time after irradiation, temperature, radiation history, photobleaching, OH and impurity content, dopant type and concentration is described. The performance of candidate components of the transmission system intended for deployment in the Superconducting Super Collider Detector and primary beam tunnel nuclear environment is discussed

  16. Analog data transmission via fiber optics

    International Nuclear Information System (INIS)

    Cisneros, E.L.; Burgueno, G.F.

    1986-10-01

    In the SLAC Linear Collider Detector (SLD), as in most high-energy particle detectors, the electromagnetic noise environment is the limiting factor in electronic readout performance. Front-end electronics are particulary susceptible to electromagnetic interference (EMI), and great care has been taken to minimize its effects. The transfer of preprocessed analog signals from the detector environs, to the remote digital processing electronics, by conventional means (via metal conductors), may ultimately limit the performance of the system. Because it is highly impervious to EMI and ground loops, a fiber-optic medium has been chosen for the transmission of these signals. This paper describes several fiber-optic transmission schemes which satisfy the requirements of the SLD analog data transmission

  17. Analog data transmission via fiber optics

    International Nuclear Information System (INIS)

    Cisneros, E.L.; Burgueno, G.F.

    1987-01-01

    In the SLAC Linear Collider Detector (SLD), as in most high-energy particle detectors, the electromagnetic noise environment is the limiting factor in electronic readout performance. Front-end electronics are particularly susceptible to electromagnetic interference (EMI), and great care has been taken to minimize its effects. The transfer of preprocessed analog signals from the detector environs, to the remote digital processing electronics, by conventional means (via metal conductors), may ultimately limit the performance of the system. Because it is highly impervious to EMI and ground loops, a fiber-optic medium has been chosen for the transmission of these signals. This paper describes several fiber-optic transmission schemes which satisfy the requirements of the SLD analog data transmission

  18. Data transmission optical link for RF-GUN project

    Science.gov (United States)

    Olowski, Krzysztof; Zielinski, Jerzy; Jalmuzna, Wojciech; Pozniak, Krzysztof; Romaniuk, Ryszard

    2005-09-01

    Today, the fast optical data transmission is one of the fundamentals of modern distributed control systems. The fibers are widely use as multi-gigabit data stream medium. For a short range transmission, the multimode fibers are in common use. The data rate for this kind of transmission exceeds 10 Gbps for 10 Gigabit Ethernet and 10G Fibre Channel protocols. The Field Programmable Gate Arrays are one of the opportunities of managing the optical transmission. This article is concerning a synchronous optical transmission system via a multimode fiber. The transmission is controlled by the FPGA of two manufacturers: Xilinx and Altera. This paper contains the newest technology overview and market device parameters. It also describes a board for the optical transmission, technical details of the transmission and optical transmission results.

  19. Quantification of a cardiac biomarker in human serum using extraordinary optical transmission (EOT.

    Directory of Open Access Journals (Sweden)

    Tao Ding

    Full Text Available Nanoimprinting lithography (NIL is a manufacturing process that can produce macroscale surface areas with nanoscale features. In this paper, this technique is used to solve three fundamental issues for the application of localized surface plasmonic resonance (LSPR in practical clinical measurements: assay sensitivity, chip-to-chip variance, and the ability to perform assays in human serum. Using NIL, arrays of 140 nm square features were fabricated on a sensing area of 1.5 mm x 1.5 mm with low cost. The high reproducibility of NIL allowed for the use of a one-chip, one-measurement approach with 12 individually manufactured surfaces with minimal chip-to-chip variations. To better approximate a real world setting, all chips were modified with a biocompatible, multi-component monolayer and inter-chip variability was assessed by measuring a bioanalyte standard (2.5-75 ng/ml in the presence of a complex biofluid, human serum. In this setting, nanoimprinted LSPR chips were able to provide sufficient characteristics for a 'low-tech' approach to laboratory-based bioanalyte measurement, including: 1 sufficient size to interface with a common laboratory light source and detector without the need for a microscope, 2 high sensitivity in serum with a cardiac troponin limit of detection of 0.55 ng/ml, and 3 very low variability in chip manufacturing to produce a figure of merit (FOM of 10.5. These findings drive LSPR closer to technical comparability with ELISA-based assays while preserving the unique particularities of a LSPR based sensor, suitability for multiplexing and miniaturization, and point-of-care detections.

  20. Optical Axis Identification Technique for Free Space Optics Transmission

    Directory of Open Access Journals (Sweden)

    Yuki Tashiro

    2017-07-01

    Full Text Available This paper describes optical axis adjustment technique for an active free space optics transmission system. This system precisely controls the direction of a collimated thin laser beam using a motor driven laser emitting mechanism and positioning photodiodes. Before beginning laser beam feedback control, it is required to guide the laser beam within the range of the positioning photodiodes for initial laser beam alignment. This paper proposes an arrival position presumption method of laser beam traveling along the long distance from transmitter. A positioning sensor containing several photodiodes measures laser luminescence distribution, and analytically calculates the optical axis of laser beam according to the modified Gaussian beam optics based on four or five distributed local intensity of laser luminescence. Experiments are conducted to evaluate the accuracy of the presumption, and results reveal that the method is effective in leading the laser beam onto a distant receiver.

  1. Using a Semiconductor-to-Metal Transition to Control Optical Transmission through Subwavelength Hole Arrays

    Directory of Open Access Journals (Sweden)

    E. U. Donev

    2008-01-01

    Full Text Available We describe a simple configuration in which the extraordinary optical transmission effect through subwavelength hole arrays in noble-metal films can be switched by the semiconductor-to-metal transition in an underlying thin film of vanadium dioxide. In these experiments, the transition is brought about by thermal heating of the bilayer film. The surprising reverse hysteretic behavior of the transmission through the subwavelength holes in the vanadium oxide suggest that this modulation is accomplished by a dielectric-matching condition rather than plasmon coupling through the bilayer film. The results of this switching, including the wavelength dependence, are qualitatively reproduced by a transfer matrix model. The prospects for effecting a similar modulation on a much faster time scale by using ultrafast laser pulses to trigger the semiconductor-to-metal transition are also discussed.

  2. Power Transmission by Optical Fibers for Component Inherent Communication

    Directory of Open Access Journals (Sweden)

    Michael Dumke

    2010-02-01

    Full Text Available The use of optical fibers for power transmission has been investigated intensely. An optically powered device combined with optical data transfer offers several advantages compared to systems using electrical connections. Optical transmission systems consist of a light source, a transmission medium and a light receiver. The overall system performance depends on the efficiency of opto-electronic converter devices, temperature and illumination dependent losses, attenuation of the transmission medium and coupling between transmitter and fiber. This paper will summarize the state of the art for optically powered systems and will discuss reasons for negative influences on efficiency. Furthermore, an outlook on power transmission by the use of a new technology for creating polymer optical fibers (POF via micro dispensing will be given. This technology is capable to decrease coupling losses by direct contacting of opto-electronic devices.

  3. Possibilities for Advanced Encoding Techniques at Signal Transmission in the Optical Transmission Medium

    Directory of Open Access Journals (Sweden)

    Filip Čertík

    2016-01-01

    Full Text Available This paper presents a possible simulation of negative effects in the optical transmission medium and an analysis for the utilization of different signal processing techniques at the optical signal transmission. An attention is focused on the high data rate signal transmission in the optical fiber influenced by linear and nonlinear environmental effects presented by the prepared simulation model. The analysis includes possible utilization of OOK, BPSK, DBPSK, BFSK, QPSK, DQPSK, 8PSK, and 16QAM modulation techniques together with RS, BCH, and LDPC encoding techniques for the signal transmission in the optical fiber. Moreover, the prepared simulation model is compared with real optical transmission systems. In the final part, a comparison of the selected modulation techniques with different encoding techniques and their implementation in real transmission systems is shown.

  4. Optical data transmission at the superconducting super collider

    International Nuclear Information System (INIS)

    Leskovar, B.

    1989-02-01

    Digital and analog data transmissions via fiber optics for the Superconducting Super Collider have been investigated. The state of the art of optical transmitters, low loss fiber waveguides, receivers and associated electronics components are reviewed and summarized. Emphasis is placed on the effects of the radiation environment on the performance of an optical data transmission system components. Also, the performance of candidate components of the wide band digital and analog transmission systems intended for deployment of the Superconducting Super Collider Detector is discussed. 27 refs., 15 figs

  5. Digital processing optical transmission and coherent receiving techniques

    CERN Document Server

    Binh, Le Nguyen

    2013-01-01

    With coherent mixing in the optical domain and processing in the digital domain, advanced receiving techniques employing ultra-high speed sampling rates have progressed tremendously over the last few years. These advances have brought coherent reception systems for lightwave-carried information to the next stage, resulting in ultra-high capacity global internetworking. Digital Processing: Optical Transmission and Coherent Receiving Techniques describes modern coherent receiving techniques for optical transmission and aspects of modern digital optical communications in the most basic lines. The

  6. Subcarrier multiplexing tolerant dispersion transmission system employing optical broadband sources.

    Science.gov (United States)

    Grassi, Fulvio; Mora, José; Ortega, Beatriz; Capmany, José

    2009-03-16

    This paper presents a novel SCM optical transmission system for next-generation WDM-PONs combining broadband optical sources and a Mach-Zehnder interferometric structure. The approach leeds to transport RF signals up to 50 GHz being compatible with RoF systems since a second configuration has been proposed in order to overcome dispersion carrier suppression effect using DSB modulation. The theoretical analysis validates the potentiality of the system also considering the effects of the dispersion slope over the transmission window. (c) 2009 Optical Society of America

  7. 40 Gb/s optical transmission systems

    DEFF Research Database (Denmark)

    Buxens Azcoaga, Alvaro Juan; Nielsen, Steen Krogh

    2003-01-01

    ; chromatic dispersion, Polarization Mode Dispersion (PMD), Self Phase Modulation (SPM) and linear or non-linear crosstalk among others. Regarding chromatic dispersion, sufficient evidence is presented for the need in 40 Gb/s systems of either modulation formats that allow for higher tolerance than....... Using a 9 ps pulsed RZ Tx, transmission is achieved over a 400 km link consisting of 5 spans of 80 km standard-SMF with a Quality (Q) factor of 17.7 dB, while for NRZ it is reduced to 15 dB. In another experimental verification over 40 km spans of standard-SMF, we could achieve transmission over 6 spans...

  8. Selective optical transmission in anisotropic multilayers structure

    International Nuclear Information System (INIS)

    Ouchani, N.; Bria, D.; Nougaoui, A.; Merad, A.E.

    2007-08-01

    We developed a Green's function method to study theoretically a single-defect photonic crystal composed of anisotropic dielectric materials. This structure can trap light of a given frequency range and filter only a certain frequency light with a very high quality. It is shown that the defect modes appear as peaks in the transmission spectrum. Their intensities and frequency positions depend on the incidence angle and the orientation of the principal axes of layers consisting of the superlattice and the layer defect. Our structure offers a great variety of possibilities for creating and controlling the number and transmitted intensities of defect modes. It can be a good candidate for realizing a selective electromagnetic filter. In addition to this filtration process, the defective anisotropic photonic crystal can be used to switch the modes when appropriate geometry is selected. (author)

  9. Photonic layer security in fiber-optic networks and optical OFDM transmission

    Science.gov (United States)

    Wang, Zhenxing

    Currently the Internet is experiencing an explosive growth in the world. Such growth leads to an increased data transmission rate demand in fiber-optical networks. Optical orthogonal frequency multiplexing (OFDM) is considered as a promising solution to achieve data rate beyond 100Gb/s per wavelength channel. In the meanwhile, because of extensive data transmission and sharing, data security has become an important problem and receives considerable attention in current research literature. This thesis focuses on data security issues at the physical layer of optical networks involving code-division multiple access (CDMA) systems and steganography methods. The thesis also covers several implementation issues in optical OFDM transmission. Optical CDMA is regarded as a good candidate to provide photonic layer security in multi-access channels. In this thesis we provide a systematic analysis of the security performance of incoherent optical CDMA codes. Based on the analysis, we proposed and experimentally demonstrated several methods to improve the security performance of the optical CDMA systems, such as applying all-optical encryption, and code hopping using nonlinear wavelength conversion. Moreover, we demonstrate that the use of wireless CDMA codes in optical systems can enhance the security in one single-user end-to-end optical channel. Optical steganography is another method to provide photonic data security and involves hiding the existence of data transmissions. In the thesis, we demonstrate that an optical steganography channel can exist in phase modulated public channels as well as traditional on-off-keying (OOK) modulated channels, without data synchronization. We also demonstrate an optical steganography system with enhanced security by utilizing temporal phase modulation techniques. Additionally, as one type of an overlay channel, the optical steganography technology can carry the sensor data collected by wireless sensor network on top of public optical

  10. High-Order Modulation for Optical Fiber Transmission

    CERN Document Server

    Seimetz, Matthias

    2009-01-01

    Catering to the current interest in increasing the spectral efficiency of optical fiber networks by the deployment of high-order modulation formats, this monograph describes transmitters, receivers and performance of optical systems with high-order phase and quadrature amplitude modulation. In the first part of the book, the author discusses various transmitter implementation options as well as several receiver concepts based on direct and coherent detection, including designs of new structures. Hereby, both optical and electrical parts are considered, allowing the assessment of practicability and complexity. In the second part, a detailed characterization of optical fiber transmission systems is presented, regarding a wide range of modulation formats. It provides insight in the fundamental behavior of different formats with respect to relevant performance degradation effects and identifies the major trends in system performance.

  11. Protocol independent transmission method in software defined optical network

    Science.gov (United States)

    Liu, Yuze; Li, Hui; Hou, Yanfang; Qiu, Yajun; Ji, Yuefeng

    2016-10-01

    With the development of big data and cloud computing technology, the traditional software-defined network is facing new challenges (e.i., ubiquitous accessibility, higher bandwidth, more flexible management and greater security). Using a proprietary protocol or encoding format is a way to improve information security. However, the flow, which carried by proprietary protocol or code, cannot go through the traditional IP network. In addition, ultra- high-definition video transmission service once again become a hot spot. Traditionally, in the IP network, the Serial Digital Interface (SDI) signal must be compressed. This approach offers additional advantages but also bring some disadvantages such as signal degradation and high latency. To some extent, HD-SDI can also be regard as a proprietary protocol, which need transparent transmission such as optical channel. However, traditional optical networks cannot support flexible traffics . In response to aforementioned challenges for future network, one immediate solution would be to use NFV technology to abstract the network infrastructure and provide an all-optical switching topology graph for the SDN control plane. This paper proposes a new service-based software defined optical network architecture, including an infrastructure layer, a virtualization layer, a service abstract layer and an application layer. We then dwell on the corresponding service providing method in order to implement the protocol-independent transport. Finally, we experimentally evaluate that proposed service providing method can be applied to transmit the HD-SDI signal in the software-defined optical network.

  12. Recent progress on high-speed optical transmission

    Directory of Open Access Journals (Sweden)

    Jianjun Yu

    2016-05-01

    Full Text Available The recently reported high spectral efficiency (SE and high-baud-rate signal transmission are all based on digital coherent optical communications and digital signal processing (DSP. DSP simplifies the reception of advanced modulation formats and also enables the major electrical and optical impairments to be processed and compensated in the digital domain, at the transmitter or receiver side. In this paper, we summarize the research progress on high-speed signal generation and detection and also show the progress on DSP for high-speed signal detection. We also report the latest progress on multi-core and multi-mode multiplexing.

  13. Precise timing signal transmission by a new optical fiber cable

    International Nuclear Information System (INIS)

    Tanaka, Shigeru; Murakami, Yasunori; Sato, Yoshihiro; Urakawa, Junji.

    1990-05-01

    For the precise timing signal transmission, a new optical fiber cable system was developed and installed between the 2.5GeV LINAC gun room and the TRISTAN control room. This fiber cable showed the reduced thermal transmission delay change less than 10psec/km in the temperature range from -20 to 30degC (average 0.04ppm/degC), which is 100 times smaller than that of any other existing coaxial cables and conventional optical fiber cables. The developed optical to electrical (O/E) and electrical to optical (E/O) converters also achieved the timing accuracy within 11psec over the temperature range from 10 to 35degC. The installed cable system in KEK eliminated the necessity of adjusting the phase drift of the TRISTAN Accumulation Ring (AR) RF signal (508MHz), which was required with the former coaxial cable due to the temperature change in a year. Measured full width of jitter over the installed 1600m fiber link was 18.8psec. (author)

  14. Photoluminescence and optical transmission of diamond and its imitators

    International Nuclear Information System (INIS)

    Lipatov, E.I.; Avdeev, S.M.; Tarasenko, V.F.

    2010-01-01

    Photoluminescence and optical transmission spectra of several samples of natural and synthetic diamond and its imitators - fianite and corundum - are investigated. The band-A of luminescence at 440 nm, the vibronic N3 system of luminescence and absorption at 415.2 nm, the fundamental absorption edge at 225 nm, and the secondary absorption below 308 nm are the main identifying markers of natural diamonds. For synthetic diamonds, however, such identifying markers are the free-exciton luminescence at 235 nm, the band-A, and the fundamental absorption edge. Fianites can be identified by the structureless wideband at 500 nm and the wide transmission band in the entire visible range. Colored corundum samples with chrome impurities emit the narrow line at 693 nm and show the absorption band in the 500-600 nm spectral range. A new method for diamond express identification is developed on the basis of measurement of photoluminescence and optical transmission spectra of the samples. It is shown that a diamond tester can be designed combining a spectrometer and a KrCl-excilamp radiating at 222 nm.

  15. An optical ASK and FSK phase diversity transmission system

    Science.gov (United States)

    Vandenboom, H.; Vanetten, W.; Dekrom, W. H. C.; Vanbennekom, P.; Huijskens, F.; Niessen, L.; Deleijer, F.

    1992-12-01

    The results of a contribution to an electrooptical project for a 'phase diversity system', covering ASK and FSK (Amplitude and Frequency Shift Keying), are described. Specifications of subsystems, and tolerances and consequences of these tolerances for the final system performance, were derived. For the optical network of the phase diversity receiver, a manufacturing set up for three by three fused biconical taper fiber couplers was developed. In order to characterize planar optical networks, a set up was constructed to measure the phase relations at 1523 nm. The optical frequency of the local oscillator laser has to be locked on to the frequency of the received optical signal. This locking circuit is described. A complete optical three by three phase diversity transmission system was developed that can be used as a testbed for subsystems. The sensitivity of the receiver at a bit error rate of 10 to the minus 9th power is -47.2 dBm, which is 4.2 dB better than the value of the specifications.

  16. Optical power allocation for adaptive transmissions in wavelength-division multiplexing free space optical networks

    Directory of Open Access Journals (Sweden)

    Hui Zhou

    2015-08-01

    Full Text Available Attracting increasing attention in recent years, the Free Space Optics (FSO technology has been recognized as a cost-effective wireless access technology for multi-Gigabit rate wireless networks. Radio on Free Space Optics (RoFSO provides a new approach to support various bandwidth-intensive wireless services in an optical wireless link. In an RoFSO system using wavelength-division multiplexing (WDM, it is possible to concurrently transmit multiple data streams consisting of various wireless services at very high rate. In this paper, we investigate the problem of optical power allocation under power budget and eye safety constraints for adaptive WDM transmission in RoFSO networks. We develop power allocation schemes for adaptive WDM transmissions to combat the effect of weather turbulence on RoFSO links. Simulation results show that WDM RoFSO can support high data rates even over long distance or under bad weather conditions with an adequate system design.

  17. Optical nonreciprocal transmission in an asymmetric silicon photonic crystal structure

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zheng; Chen, Juguang; Ji, Mengxi; Huang, Qingzhong; Xia, Jinsong; Wang, Yi, E-mail: yingwu2@126.com, E-mail: ywangwnlo@mail.hust.edu.cn [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Wu, Ying, E-mail: yingwu2@126.com, E-mail: ywangwnlo@mail.hust.edu.cn [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)

    2015-11-30

    An optical nonreciprocal transmission (ONT) is realized by employing the nonlinear effects in a compact asymmetric direct-coupled nanocavity-waveguide silicon photonic crystal structure with a high loaded quality factor (Q{sub L}) of 42 360 and large extinction ratio exceeding 30 dB. Applying a single step lithography and successive etching, the device can realize the ONT in an individual nanocavity, alleviating the requirement to accurately control the resonance of the cavities. A maximum nonreciprocal transmission ratio of 21.1 dB as well as a working bandwidth of 280 pm in the telecommunication band are obtained at a low input power of 76.7 μW. The calculated results by employing a nonlinear coupled-mode model are in good agreement with the experiment.

  18. Optical transmission properties of Pentelic and Paros marble

    OpenAIRE

    Weigand Talavera, Rosa María; García, Pablo A.; Campos Acosta, Joaquín; Storch de Gracía, Jacobo

    2015-01-01

    AncientGreek and Roman sources report that the statue of Zeus in Olympia had a head, and in particular eyes, similar to the description of Zeus by Homer, so we think that the statue was visible to the human eye. Since the temple was 12mhigh, and had a small door and no windows, the illumination of the statue by conventionalmedia is questionable. The aimof this paper is to characterize the optical transmission of Paros and Pentelic marble to demonstrate that it was possible to have the Zeus te...

  19. Evaluation of Fibre Lifetime in Optical Ground Wire Transmission Lines

    Science.gov (United States)

    Grunvalds, R.; Ciekurs, A.; Porins, J.; Supe, A.

    2017-06-01

    In the research, measurements of polarisation mode dispersion of two OPGWs (optical ground wire transmission lines), in total four fibres, have been carried out, and the expected lifetime of the infrastructure has been assessed on the basis of these measurements. The cables under consideration were installed in 1995 and 2011, respectively. Measurements have shown that polarisation mode dispersion values for cable installed in 1995 are four times higher than that for cable installed in 2011, which could mainly be explained by technological differences in fibre production and lower fibre polarisation mode dispersion requirements in 1995 due to lack of high-speed (over 10 Gbit/s) optical transmission systems. The calculation methodology of non-refusal work and refusal probabilities, using the measured polarisation mode dispersion parameters, is proposed in the paper. Based on reliability calculations, the expected lifetime is then predicted, showing that all measured fibres most likely will be operational within minimum theoretical service life of 25 years accepted by the industry.

  20. Optical transmission theory for metal-insulator-metal periodic nanostructures

    Directory of Open Access Journals (Sweden)

    Blanchard-Dionne Andre-Pierre

    2016-11-01

    Full Text Available A semi-analytical formalism for the optical properties of a metal-insulator-metal periodic nanostructure using coupled-mode theory is presented. This structure consists in a dielectric layer in between two metallic layers with periodic one-dimensional nanoslit corrugation. The model is developed using multiple-scattering formalism, which defines transmission and reflection coefficients for each of the interface as a semi-infinite medium. Total transmission is then calculated using a summation of the multiple paths of light inside the structure. This method allows finding an exact solution for the transmission problem in every dimension regime, as long as a sufficient number of diffraction orders and guided modes are considered for the structure. The resonant modes of the structure are found to be related to the metallic slab only and to a combination of both the metallic slab and dielectric layer. This model also allows describing the resonant behavior of the system in the limit of a small dielectric layer, for which discontinuities in the dispersion curves are found. These discontinuities result from the out-of-phase interference of the different diffraction orders of the system, which account for field interaction for both inner interfaces of the structure.

  1. Ordinary and extraordinary means.

    Science.gov (United States)

    Gillon, R

    1986-01-25

    The Roman Catholic doctrine of ordinary and extraordinary means in patient care decisions is the subject of this essay in Gillon's series on medical ethics. He briefly traces the Church history of this doctrine, which holds that saving life is not obligatory if doing so would be excessively burdensome or disproportionate in relation to the expected benefits. The burdens and benefits are to be weighed in the context of "circumstances of persons, places, times, and cultures," and factors such as the costs and risks of undergoing a proposed treatment may be considered. Gillon also notes the disagreement among Roman Catholic commentators over whether it is ever permissible to discontinue feeding as a burdensome, extraordinary treatment. He concludes that, despite different weightings of harms and benefits, Roman Catholic and non-Catholic thinkers are in accord over the appropriate moral approach to deciding when treatment is not obligatory.

  2. Optical vortex discrimination with a transmission volume hologram

    Energy Technology Data Exchange (ETDEWEB)

    Gruneisen, Mark T [Air Force Research Laboratory, Directed Energy Directorate, Kirtland AFB, NM 87117 (United States); Dymale, Raymond C; Stoltenberg, Kurt E [Boeing Company, PO Box 5670, Albuquerque, NM 87185 (United States); Steinhoff, Nicholas [Optical Sciences Company, 1341 S Sunkist St., Anaheim, CA 92806 (United States)

    2011-08-15

    Transmissive volume holograms are considered as mode-selective optical elements for the de-multiplexing and detecting of optical vortex modes according to the topological charge or mode number. Diffraction of vortex modes by a fundamental mode hologram is modeled using a physical optics model that treats the volume hologram as an angle-dependent transfer function. Diffracted irradiance profiles and diffraction efficiencies are calculated numerically as a function of the incident mode number. The results of the model are compared with experimental results obtained with volume holograms of fundamental and higher-order vortex modes. When considered as a function of detuning between the incident and recorded mode numbers, the measured diffraction efficiencies are found to be invariant with respect to the recorded mode number, provided that the order difference remains unchanged, and in close agreement with the predictions of the model. Measurements are made with a 1.3 mm thick permanent photo-thermo-refractive glass hologram and a 9 mm thick re-writable photorefractive lithium niobate hologram. A liquid-crystal spatial light modulator generates the vortex modes used to record and read the holograms. The results indicate that a simple volume hologram can discriminate between vortex modes; however, adjacent mode discrimination with low crosstalk would require a very thick hologram. Furthermore, broadening of the vortex angular spectrum, due to diffraction at a finite aperture, can adversely affect diffraction efficiencies.

  3. Optical vortex discrimination with a transmission volume hologram

    International Nuclear Information System (INIS)

    Gruneisen, Mark T; Dymale, Raymond C; Stoltenberg, Kurt E; Steinhoff, Nicholas

    2011-01-01

    Transmissive volume holograms are considered as mode-selective optical elements for the de-multiplexing and detecting of optical vortex modes according to the topological charge or mode number. Diffraction of vortex modes by a fundamental mode hologram is modeled using a physical optics model that treats the volume hologram as an angle-dependent transfer function. Diffracted irradiance profiles and diffraction efficiencies are calculated numerically as a function of the incident mode number. The results of the model are compared with experimental results obtained with volume holograms of fundamental and higher-order vortex modes. When considered as a function of detuning between the incident and recorded mode numbers, the measured diffraction efficiencies are found to be invariant with respect to the recorded mode number, provided that the order difference remains unchanged, and in close agreement with the predictions of the model. Measurements are made with a 1.3 mm thick permanent photo-thermo-refractive glass hologram and a 9 mm thick re-writable photorefractive lithium niobate hologram. A liquid-crystal spatial light modulator generates the vortex modes used to record and read the holograms. The results indicate that a simple volume hologram can discriminate between vortex modes; however, adjacent mode discrimination with low crosstalk would require a very thick hologram. Furthermore, broadening of the vortex angular spectrum, due to diffraction at a finite aperture, can adversely affect diffraction efficiencies.

  4. Technical aspects of the use of optical fibers for data transmission in particle physics

    International Nuclear Information System (INIS)

    Petrolo, E.

    1991-01-01

    This presentation will discuss the major technical aspects related to the use of optical fibers for data transmission in particle physics. The different possibilities of use of optical links for different experimental applications and environments will be presented with an overview of the technical problems in the use of optical transmission components, such as fibers and their radiation damage, emitters, detectors, cables, transmission systems, etc. (orig.)

  5. Transmission electron microscope sample holder with optical features

    Science.gov (United States)

    Milas, Mirko [Port Jefferson, NY; Zhu, Yimei [Stony Brook, NY; Rameau, Jonathan David [Coram, NY

    2012-03-27

    A sample holder for holding a sample to be observed for research purposes, particularly in a transmission electron microscope (TEM), generally includes an external alignment part for directing a light beam in a predetermined beam direction, a sample holder body in optical communication with the external alignment part and a sample support member disposed at a distal end of the sample holder body opposite the external alignment part for holding a sample to be analyzed. The sample holder body defines an internal conduit for the light beam and the sample support member includes a light beam positioner for directing the light beam between the sample holder body and the sample held by the sample support member.

  6. A novel optical transmission link with DHT-based constant envelope optical OFDM signal

    Science.gov (United States)

    Ma, Jianxin; Liang, Hao

    2013-07-01

    In this paper, we have proposed a novel optical OFDM transmission link that takes advantages of discrete Hartley Transform (DHT) and constant envelope (CE) modulation, obtaining DHT-based constant envelope optical OFDM. The numerical results show that this design achieves better performance when compared with conventional O-OFDM in terms of bit error rate (BER) and peak-to-average power ratio (PAPR). The impact of phase modulation index (PMI) on both PAPR and noise tolerance is investigated. Since the scheme has simplified design, it is believed to be a cost-effective in the practical implement.

  7. Effects of optical layer impairments on 2.5 Gb/s optical CDMA transmission.

    Science.gov (United States)

    Feng, H; Mendez, A; Heritage, J; Lennon, W

    2000-07-03

    We conducted a computer simulation study to assess the effects of optical layer impairments on optical CDMA (O-CDMA) transmission of 8 asynchronous users at 2.5 Gb/s each user over a 214-km link. It was found that with group velocity dispersion compensation, two other residual effects, namely, the nonzero chromatic dispersion slope of the single mode fiber (which causes skew) and the non-uniform EDFA gain (which causes interference power level to exceed signal power level of some codes) degrade the signal to multi-access interference (MAI) ratio. In contrast, four wave mixing and modulation due to the Kerr and Raman contributions to the fiber nonlinear refractive index are less important. Current wavelength-division multiplexing (WDM) technologies, including dispersion management, EDFA gain flattening, and 3 rd order dispersion compensation, are sufficient to overcome the impairments to the O-CDMA transmission system that we considered.

  8. MFTF-B quasi-optical ECRH transmission system

    International Nuclear Information System (INIS)

    Yugo, J.J.; Shearer, J.W.; Ziolkowski, R.W.

    1983-01-01

    The microwave transmission system for ERCH on MFTF-B will utilize quasi-optical transmission techniques. The system consists of ten gyrotron oscillators: two gyrotrons at 28 GHz, two at 35 GHz, and six at 56 GHz. The 28 and 35 GHz gyrotrons both heat the electrons in the end plug (potential peak) while the 56 GHz sources heat the minimum-B anchor region (potential minimum). Microwaves are launched into a pair of cylindrical mirrors that form a pseudo-cavity which directs the microwaves through the plasma numerous times before they are lost out of the cavity. The cavity allows the microwave beam to reach the resonance zone over a wide range of plasma densities and temperatures. The fundamental electron cyclotron resonance moves to higher axial positions as a result of beta-depression of the magnetic field, doppler shifting of the resonance, and relativistic mass corrections for the electrons. With this system the microwave beam will reach the resonance surface at the correct angle of incidence for any density or temperature without active aiming of the antennas. The cavity also allows the beam to make multiple passes through the plasma to increase the heating efficiency at low temperatures and densities when the single pass absorption is low. In addition, neutral beams and diagnostics have an unobstructed view of the plasma

  9. Noise and signal interference in optical fiber transmission systems an optimum design approach

    CERN Document Server

    Bottacchi, Stefano

    2008-01-01

    A comprehensive reference to noise and signal interference in optical fiber communications Noise and Signal Interference in Optical Fiber Transmission Systems is a compendium on specific topics within optical fiber transmission and the optimization process of the system design. It offers comprehensive treatment of noise and intersymbol interference (ISI) components affecting optical fiber communications systems, containing coverage on noise from the light source, the fiber and the receiver. The ISI is modeled with a statistical approach, leading to new useful computational m

  10. IQ imbalance tolerable parallel-channel DMT transmission for coherent optical OFDMA access network

    Science.gov (United States)

    Jung, Sang-Min; Mun, Kyoung-Hak; Jung, Sun-Young; Han, Sang-Kook

    2016-12-01

    Phase diversity of coherent optical communication provides spectrally efficient higher-order modulation for optical communications. However, in-phase/quadrature (IQ) imbalance in coherent optical communication degrades transmission performance by introducing unwanted signal distortions. In a coherent optical orthogonal frequency division multiple access (OFDMA) passive optical network (PON), IQ imbalance-induced signal distortions degrade transmission performance by interferences of mirror subcarriers, inter-symbol interference (ISI), and inter-channel interference (ICI). We propose parallel-channel discrete multitone (DMT) transmission to mitigate transceiver IQ imbalance-induced signal distortions in coherent orthogonal frequency division multiplexing (OFDM) transmissions. We experimentally demonstrate the effectiveness of parallel-channel DMT transmission compared with that of OFDM transmission in the presence of IQ imbalance.

  11. Multirate IP traffic transmission in flexible access networks based on optical FFH-CDMA

    DEFF Research Database (Denmark)

    Raddo, Thiago R.; Sanches, Anderson L.; Tafur Monroy, Idelfonso

    2016-01-01

    In this paper, we propose a new IP transmission architecture over optical fast frequency hopping code-division multiple-access (OFFH-CDMA) network capable of supporting multirate transmissions for applications in flexible optical access networks. The proposed network architecture is independent...

  12. Fiber-optic data-transmission system for borehole logging. Final report. National Uranium Resource Evaluation

    International Nuclear Information System (INIS)

    Gould, G.

    1981-01-01

    The purpose of the system is to provide signal transmission media for transmission of digital data from a borehole logging probe (and associated processor-electronics) to a borehole logging truck at the surface. This fiber optic transmission system is specifically designed for use on the Bendix Field Engineering Corp. (BFEC) R and D logging truck

  13. Optical transmission properties of Pentelic and Paros marble.

    Science.gov (United States)

    Weigand, Rosa; García, Pablo A; Campos Acosta, Joaquín; Storch de Gracia, Jacobo

    2015-02-01

    Ancient Greek and Roman sources report that the statue of Zeus in Olympia had a head, and in particular eyes, similar to the description of Zeus by Homer, so we think that the statue was visible to the human eye. Since the temple was 12 m high, and had a small door and no windows, the illumination of the statue by conventional media is questionable. The aim of this paper is to characterize the optical transmission of Paros and Pentelic marble to demonstrate that it was possible to have the Zeus temple illuminated through the roof marble tiles. Spectral absolute transmittance measurements were taken in samples with different thicknesses using a calibrated spectrophotometer, as well as total transmittance measurements using a luxmeter. The results show that both types of marble transmit light and that Pentelic marble has a higher transmittance in the visible range than Paros marble in some cases and hence could have been one reason, among others, to change the type of marble in the roof in antiquity.

  14. Giga-bit optical data transmission module for Beam Instrumentation

    CERN Document Server

    Roedne, L T; Cenkeramaddi, L R; Jiao, L

    Particle accelerators require electronic instrumentation for diagnostic, assessment and monitoring during operation of the transferring and circulating beams. A sensor located near the beam provides an electrical signal related to the observable quantity of interest. The front-end electronics provides analog-to-digital conversion of the quantity being observed and the generated data are to be transferred to the external digital back-end for data processing, and to display to the operators and logging. This research project investigates the feasibility of radiation-tolerant giga-bit data transmission over optic fibre for beam instrumentation applications, starting from the assessment of the state of the art technology, identification of challenges and proposal of a system level solution, which should be validated with a PCB design in an experimental setup. Radiation tolerance of 10 kGy (Si) Total Ionizing Dose (TID) over 10 years of operation, Bit Error Rate (BER) 10-6 or better. The findings and results of th...

  15. Bioinspired Superhydrophobic Highly Transmissive Films for Optical Applications.

    Science.gov (United States)

    Vüllers, Felix; Gomard, Guillaume; Preinfalk, Jan B; Klampaftis, Efthymios; Worgull, Matthias; Richards, Bryce; Hölscher, Hendrik; Kavalenka, Maryna N

    2016-11-01

    Inspired by the transparent hair layer on water plants Salvinia and Pistia, superhydrophobic flexible thin films, applicable as transparent coatings for optoelectronic devices, are introduced. Thin polymeric nanofur films are fabricated using a highly scalable hot pulling technique, in which heated sandblasted steel plates are used to create a dense layer of nano- and microhairs surrounding microcavities on a polymer surface. The superhydrophobic nanofur surface exhibits water contact angles of 166 ± 6°, sliding angles below 6°, and is self-cleaning against various contaminants. Additionally, subjecting thin nanofur to argon plasma reverses its surface wettability to hydrophilic and underwater superoleophobic. Thin nanofur films are transparent and demonstrate reflection values of less than 4% for wavelengths ranging from 300 to 800 nm when attached to a polymer substrate. Moreover, used as translucent self-standing film, the nanofur exhibits transmission values above 85% and high forward scattering. The potential of thin nanofur films for extracting substrate modes from organic light emitting diodes is tested and a relative increase of the luminous efficacy of above 10% is observed. Finally, thin nanofur is optically coupled to a multicrystalline silicon solar cell, resulting in a relative gain of 5.8% in photogenerated current compared to a bare photovoltaic device. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Holographic Optical Elements Recorded in Silver Halide Sensitized Gelatin Emulsions. Part I. Transmission Holographic Optical Elements

    Science.gov (United States)

    Kim, Jong Man; Choi, Byung So; Kim, Sun Il; Kim, Jong Min; Bjelkhagen, Hans I.; Phillips, Nicholas J.

    2001-02-01

    Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOE s). The drawback of DCG is its low sensitivity and limited spectral response. Silver halide materials can be processed in such a way that the final hologram will have properties like a DCG hologram. Recently this technique has become more interesting since the introduction of new ultra-high-resolution silver halide emulsions. An optimized processing technique for transmission HOE s recorded in these materials is introduced. Diffraction efficiencies over 90% can be obtained for transmissive diffraction gratings. Understanding the importance of the selective hardening process has made it possible to obtain results similar to conventional DCG processing. The main advantage of the SHSG process is that high-sensitivity recording can be performed with laser wavelengths anywhere within the visible spectrum. This simplifies the manufacturing of high-quality, large-format HOE s.

  17. Real-time all-optical OFDM transmission system based on time-domain optical fourier transformation

    DEFF Research Database (Denmark)

    Guan, Pengyu; Kong, Deming; Røge, Kasper Meldgaard

    2014-01-01

    We propose a novel simple all-optical OFDM transmission system based on time-domain OFT using time-lenses. A real-time 160 Gbit/s DPSK OFDM transmission with 16 decorrelated data subcarriers is successfully demonstrated over 100 km....

  18. Growth of optical transmission loss at 850 nm in silica core optical fibers during fission reactor irradiation

    International Nuclear Information System (INIS)

    Shikama, T.; Narui, M.; Sagawa, T.

    1998-01-01

    Pure, OH-doped and F-doped silica core optical fibers were irradiated in a fission reactor at 400±10 K using an electric heater at a reactor power greater than 10 MW (20% of the full power). The temperature was not controlled well at the early stage of the reactor startup, when the temperature was about 320-340 K. The optical fibers were irradiated with a fast neutron (E>1 MeV) flux of 3.2 x 10 17 n/cm 2 s and a gamma dose rate of 3 x 10 3 Gy/s for 527 h. Optical transmission loss at 850 nm was measured in situ during irradiation. A prompt increase in optical transmission loss was observed as irradiation started, which was probably due to dynamic irradiation effects caused by short-lived and transient defects and is probably recoverable when irradiation ceases. After the prompt increase in optical transmission loss, a so-called radiation hardening was observed in fibers containing OH. Radiation hardening was also observed in 900 ppm OH-doped fiber at the second startup. The optical transmission loss increased linearly with irradiation dose, denoted as the accumulated loss, which we believe is due to irradiation-induced long-lived defects. Accumulated loss dominates radiation-induced optical transmission loss in a fission reactor irradiation. (orig.)

  19. Information transmission via fiber optics in the shiva laser control system

    International Nuclear Information System (INIS)

    Parker, J.

    1978-01-01

    The Fiber Optic Serial Link package performs the functions of transmission and reception of signals over a pair of fiber optic cables and the I/O of serial data to a local device in EIA format. Present sysems requirements include fiber cable transmission length of up to 150 m and baud rates up to 9600, although the design criterium of transmission at 19.2 KB has been met. Fiber optic links are used between the central control area and each of the alignment control subsystems, in addition to sending timing signals over long distances between subsystems

  20. 30-Gb/s bidirectional transparent optical transmission with an MMF access and an indoor optical wireless link

    NARCIS (Netherlands)

    Chen, H.; Boom, van den H.P.A.; Tangdiongga, E.; Koonen, A.M.J.

    2012-01-01

    This letter describes a 30-Gb/s bidirectional transparent optical transmission, over a 4.4-km multimode fiber (MMF) in combination with an indoor optical wireless (OW) link, which could provide limited mobility. Due to MMF's advantages, such as lower installation costs and easy maintenance, it is

  1. Precision-analog fiber-optic transmission system

    International Nuclear Information System (INIS)

    Stover, G.

    1981-06-01

    This article describes the design, experimental development, and construction of a DC-coupled precision analog fiber optic link. Topics to be covered include overall electrical and mechanical system parameters, basic circuit organization, modulation format, optical system design, optical receiver circuit analysis, and the experimental verification of the major design parameters

  2. Study of light transmission through optical fiber-to-fiber connector assemblies

    International Nuclear Information System (INIS)

    Chung, M.; Gutowski, M.; Adams, M.; Solomon, J.

    1998-01-01

    Optical fiber-to-fiber connectors are now being used widely in particle tracking detectors. We describe the properties of the connectors, their production, and measurements of the light transmission through the gap of the connector assembly. We studied light transmission for various types of connectors illuminated by several different light sources. The light transmission was found to be dependent on the angular distribution of the light rays passing through a connector assembly. Two arrangements were studied, a point source and a diffuse source. A green LED with a diffuser is believed to best reproduce the angular distributions of light in the real detector applications. We also studied the transmission as a function of the index of refraction of the optical couplants. The light transmission depends on the index of refraction of an optical couplant placed in the gap, and improves as it approaches the index of refraction of the fiber core. Light transmissions of 80%∼88% were obtained without any optical couplant in the connector gap and transmissions of 89%∼99% with various optical couplants. A Monte Carlo study using measured light distributions from a fiber end produced a reasonable agreement with the transmission measurements made on a connector assembly

  3. Study of light transmission through optical fiber-to-fiber connector assemblies

    International Nuclear Information System (INIS)

    Chung, M.; Gutowski, M.; Adams, M.; Solomon, J.

    1998-01-01

    Optical fiber-to-fiber connectors are now being used widely in particle tracking detectors. We describe the properties of the connectors, their production, and measurements of the light transmission through the gap of the connector assembly. We studied light transmission for various types of connectors illuminated by several different light sources. The light transmission was found to be dependent on the angular distribution of the light rays passing through a connector assembly. Two arrangements were studied, a point source and a diffuse source. A green LED with a diffuser is believed to best reproduce the angular distributions of light in the real detector applications. We also studied the transmission as a function of the index of refraction of the optical couplants. The light transmission depends on the index of refraction of an optical couplant placed in the gap, and improves as it approaches the index of refraction of the fiber core. Light transmissions of 80%∼88% were obtained without any optical couplant in the connector gap and transmissions of 89%∼99% with various optical couplants. A Monte Carlo study using measured light distributions from a fiber end produced a reasonable agreement with the transmission measurements made on a connector assembly. copyright 1998 American Institute of Physics

  4. Optical-wireless-optical full link for polarization multiplexing quadrature amplitude/phase modulation signal transmission.

    Science.gov (United States)

    Li, Xinying; Yu, Jianjun; Chi, Nan; Zhang, Junwen

    2013-11-15

    We propose and experimentally demonstrate an optical wireless integration system at the Q-band, in which up to 40 Gb/s polarization multiplexing multilevel quadrature amplitude/phase modulation (PM-QAM) signal can be first transmitted over 20 km single-mode fiber-28 (SMF-28), then delivered over a 2 m 2 × 2 multiple-input multiple-output wireless link, and finally transmitted over another 20 km SMF-28. The PM-QAM modulated wireless millimeter-wave (mm-wave) signal at 40 GHz is generated based on the remote heterodyning technique, and demodulated by the radio-frequency transparent photonic technique based on homodyne coherent detection and baseband digital signal processing. The classic constant modulus algorithm equalization is used at the receiver to realize polarization demultiplexing of the PM-QAM signal. For the first time, to the best of our knowledge, we realize the conversion of the PM-QAM modulated wireless mm-wave signal to the optical signal as well as 20 km fiber transmission of the converted optical signal.

  5. All-optical switching of the transmission of electromagnetic radiation through subwavelength apertures

    NARCIS (Netherlands)

    Janke, C.; Gómez Rivas, J.; Haring Bolivar, P.; Kurz, H.

    2005-01-01

    Unprecedented optical control of the surface plasmon polariton assisted transmission of terahertz radiation through subwavelength apertures is rendered possible by carrier-induced changes to the dielectric properties of a semiconductor grating. Although the study presented is static, the extension

  6. Training-based Channel Estimation for Signal Equalization and OPM in 16-QAM Optical Transmission Systems

    DEFF Research Database (Denmark)

    Pittalà, Fabio; Hauske, Fabian N.; Ye, Yabin

    2012-01-01

    Efficient channel estimation for signal equalization and OPM based on short CAZAC sequences with QPSK and 8PSK constellation formats is demonstrated in a 224-Gb/s PDM 16-QAM optical linear transmission system....

  7. Unidirectional transmission in 1D nonlinear photonic crystal based on topological phase reversal by optical nonlinearity

    OpenAIRE

    Chong Li; Xiaoyong Hu; Hong Yang; Qihuang Gong

    2017-01-01

    We propose a scheme of unidirectional transmission in a 1D nonlinear topological photonic crystal based on the topological edge state and three order optical nonlinearity. The 1D photonic crystals consists of a nonlinear photonic crystal L and a linear photonic crystal R. In the backward direction, light is totally reflected for the photons transmission prohibited by the bandgap. While in the forward direction, light interacts with the nonlinear photonic crystal L by optical Kerr effect, brin...

  8. Multi-standard transmission of converged wired and wireless services over 100m plastic optical fibre

    NARCIS (Netherlands)

    Yang, H.; Visani, D.; Okonkwo, C.M.; Shi, Y.; Tartarini, G.; Tangdiongga, E.; Koonen, A.M.J.

    2010-01-01

    The first multi-standard transmission consisting of 6 Gbit/s DMT baseband and 200 Mbit/s MB-OFDM UWB radio signals over 100m perfluorinated graded-index plastic optical fibre is demonstrated. Transmission performance indicates BER <10-5 and EVM <-22dB respectively.

  9. Optical transmission through multi-component generalized Thue-Morse superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Guogang [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, South China Normal University, Guangzhou 510631 (China); Yang Xiangbo, E-mail: xbyang@scnu.edu.c [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, South China Normal University, Guangzhou 510631 (China); Li Yuhong; Song Huanhuan [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, South China Normal University, Guangzhou 510631 (China)

    2010-09-01

    In this paper, by the three kinds of basic components (BCs) of three-component Thue-Morse (3CTM) sequence we construct a type of interesting optical basic-structural-units (BSUs) and propose multi-component generalized Thue-Morse (mCGTM) model. Based on the conventional electromagnetic wave theory we investigate the optical transmission vertically through the one-dimensional (1D) mCGTM superlattices. It is found that the optical transmission possesses an interesting pseudo-constant characteristic at the central wavelength. mCGTM sequence exhibits a cantor-set structure which results in the system possessing certain kinds of effective component pairs (ECPs), and each kind of ECP brings about certain contribution towards the optical transmission. The cantor-set structure is the reason that mCGTM multilayers exhibit the optical transmission pseudo-constant property. For the pseudo-constant optical transmission of mCGTM superlattices, there would be a potential application in the designing of some complex optical devices.

  10. High bit rate optical transmission using midspan spectral inversion ...

    African Journals Online (AJOL)

    compensation of the nonlinear and linear effects by a midspan optical phase conjugation (OPC) is studied. First, we show the impacts of chromatic dispersion ... optical amplifier technology instead of developing new amplifier technology. .... feedback (DFB) laser and by the cascade of external LiNbO3 MZMs modulator and.

  11. Data transmission optical link for LLRF TESLA project part II: application for BER measurements

    Science.gov (United States)

    Pozniak, Krzysztof T.; Romaniuk, Ryszard S.; Jalmuzna, Wojciech; Olowski, Krzysztof; Perkuszewski, Karol; Zielinski, Jerzy; Kierzkowski, Krzysztof

    2006-02-01

    It may be predicted now, even assuming a very conservative approach, that the next generation of the Low Level RF control systems for future accelerators will use extensively such technologies like: very fast programmable circuits equipped with DSP, embedded PC and optical communication I/O functionalities, as well as multi-gigabit optical transmission of measurement data and control signals.

  12. Design of an ultrafast all-optical differentiator based on a fiber Bragg grating in transmission.

    Science.gov (United States)

    Preciado, Miguel A; Muriel, Miguel A

    2008-11-01

    We propose and analyze a first-order optical differentiator based on a fiber Bragg grating (FBG) in transmission. It is shown in the examples that a simple uniform-period FBG in a very strong coupling regime (maximum reflectivity very close to 100%) can perform close to ideal temporal differentiation of the complex envelope of an arbitrary-input optical signal.

  13. Multi-carrier transmission for hybrid radio frequency with optical wireless communications

    Science.gov (United States)

    Wang, Gang; Chen, Genshe; Shen, Dan; Pham, Khanh; Blasch, Erik; Nguyen, Tien M.

    2015-05-01

    Radio frequency (RF) wireless communication is reaching its capacity to support large data rate transmissions due to hardware constraints (e.g., silicon processes), software strategies (e.g., information theory), and consumer desire for timely large file exchanges (e.g., big data and mobile cloud computing). A high transmission rate performance must keep pace with the generated huge volumes of data for real-time processing. Integrated RF and optical wireless communications (RF/OWC) could be the next generation transmission technology to satisfy both the increased data rate exchange and the communications constraints. However, with the promising benefits of RF/OWC, challenges remain to fully develop hybrid RF with wireless optical communications such as uniform waveform design for information transmission and detection. In this paper, an orthogonal frequency division multiplexing (OFDM) transmission scheme, which widely employed in RF communications, is developed for optical communications. The traditional high peak-to-average power ratio (PAPR) in OFDM is reduced to improve system performance. The proposed multi-carrier waveform is evaluated with a frequency-selective fading channel. The results demonstrate that bit error rate (BER) performance of our proposed optical OFDM transmission technique outperforms the traditional OWC on-off keying (OOK) transmission scheme.

  14. Turbo Equalization Techniques Toward Robust PDM 16-QAM Optical Fiber Transmission

    DEFF Research Database (Denmark)

    Arlunno, Valeria; Caballero Jambrina, Antonio; Borkowski, Robert

    2014-01-01

    In this paper, we show numerically and experimentally that turbo equalization (TE) is an efficient technique to mitigate performance degradations stemming from optical fiber propagation effects in both optical fiber dispersion managed and unmanaged coherent detection links. The effectiveness....... As TE can be included in the current coherent detection transceiver technologies and complement other equalization techniques, it has prospects for application in next-generation high-capacity and long-reach optical transmission links....

  15. Diagnosis of malignant tumors of female breast cancer by transmission optical tomography

    Directory of Open Access Journals (Sweden)

    I. V. Pyanov

    2012-01-01

    Full Text Available A review of the literature on diagnostic systems for the detection of breast cancer by optical tomography was presented. The actuality of the method of transmission of optical tomography and its advantages over existing methods of medical diagnosis of cancer have been substanti- ated. We have analyzed tomographic systems used for the diagnosis of breast cancer. The basic advantages and disadvantages of tomograph- ic systems using various types of radiation have been indicated. The results of review can be used in the development of technique for optical transmission tomography.

  16. Fiber optic transmission system delivered to Fusion Research Center of Japan Atomic Energy Research Institute

    International Nuclear Information System (INIS)

    Hayashida, Mutsuo; Hiramoto, Kiyoshi; Yamazaki, Kunihiro

    1983-01-01

    In general there are many electromagnetically induced noises in the premises of factories, power plants and substations. Under such electrically bad environments, for the computer data transmission that needs high speed processing and high reliability, the optical fiber cable is superion to the coaxial cable or the flat-type cable in aspects of the inductionlessness and a wide bandwidth. Showa Electric Wire and Cable Co., Ltd. has delivered and installed a computer data transmission system consisting of optical modems and optical fiber cables for connecting every experiment building in the premises of Fusion Research Center of Japan Atomic Energy Research Institute. This paper describes the outline of this system. (author)

  17. Gemini/GMOS Transmission Spectral Survey: Complete Optical Transmission Spectrum of the Hot Jupiter WASP-4b

    Science.gov (United States)

    Huitson, C. M.; Désert, J.-M.; Bean, J. L.; Fortney, J. J.; Stevenson, K. B.; Bergmann, M.

    2017-09-01

    We present the complete optical transmission spectrum of the hot Jupiter WASP-4b from 440 to 940 nm at R ˜ 400-1500 obtained with the Gemini Multi-Object Spectrometers (GMOS); this is the first result from a comparative exoplanetology survey program of close-in gas giants conducted with GMOS. WASP-4b has an equilibrium temperature of 1700 K and is favorable to study in transmission due to its large scale height (370 km). We derive the transmission spectrum of WASP-4b using four transits observed with the MOS technique. We demonstrate repeatable results across multiple epochs with GMOS, and derive a combined transmission spectrum at a precision about twice above photon noise, which is roughly equal to one atmospheric scale height. The transmission spectrum is well fitted with a uniform opacity as a function of wavelength. The uniform opacity and absence of a Rayleigh slope from molecular hydrogen suggest that the atmosphere is dominated by clouds with condensate grain sizes of ˜1 μm. This result is consistent with previous observations of hot Jupiters since clouds have been seen in planets with similar equilibrium temperatures to WASP-4b. We describe a custom pipeline that we have written to reduce GMOS time-series data of exoplanet transits, and present a thorough analysis of the dominant noise sources in GMOS, which primarily consist of wavelength- and time-dependent displacements of the spectra on the detector, mainly due to a lack of atmospheric dispersion correction.

  18. A 10 Gbit/s OCDMA system based on electric encoding and optical transmission

    Science.gov (United States)

    Li, Chuan-qi; Hu, Jin-lin; He, Dong-dong; Chen, Mei-juan; Wang, Da-chi; Chen, Yan

    2013-11-01

    An electric encoded/optical transmission system of code division multiple access (CDMA) is proposed. It encodes the user signal in electric domain, and transfers the different code slice signals via the different wavelengths of light. This electric domain encoder/decoder is compared with current traditional encoder/decoder. Four-user modulation/demodulation optical CDMA (OCDMA) system with rate of 2.5 Gbit/s is simulated, which is based on the optical orthogonal code (OCC) designed in our laboratory. The results show that the structure of electric encoding/optical transmission can encode/decode signal correctly, and can achieve the chip rate equal to the user data rate. It can overcome the rate limitation of electronic bottleneck, and bring some potential applications in the electro-optical OCDMA system.

  19. Three-dimensional optical transfer functions in the aberration-corrected scanning transmission electron microscope.

    Science.gov (United States)

    Jones, L; Nellist, P D

    2014-05-01

    In the scanning transmission electron microscope, hardware aberration correctors can now correct for the positive spherical aberration of round electron lenses. These correctors make use of nonround optics such as hexapoles or octupoles, leading to the limiting aberrations often being of a nonround type. Here we explore the effect of a number of potential limiting aberrations on the imaging performance of the scanning transmission electron microscope through their resulting optical transfer functions. In particular, the response of the optical transfer function to changes in defocus are examined, given that this is the final aberration to be tuned just before image acquisition. The resulting three-dimensional optical transfer functions also allow an assessment of the performance of a system for focal-series experiments or optical sectioning applications. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

  20. Optical transmission properties of an anisotropic defect cavity in one-dimensional photonic crystal

    Science.gov (United States)

    Ouchani, Noama; El Moussaouy, Abdelaziz; Aynaou, Hassan; El Hassouani, Youssef; El Boudouti, El Houssaine; Djafari-Rouhani, Bahram

    2018-01-01

    We investigate theoretically the possibility to control the optical transmission in the visible and infrared regions by a defective one dimensional photonic crystal formed by a combination of a finite isotropic superlattice and an anisotropic defect layer. The Green's function approach has been used to derive the reflection and the transmission coefficients, as well as the densities of states of the optical modes. We evaluate the delay times of the localized modes and we compare their behavior with the total densities of states. We show that the birefringence of an anisotropic defect layer has a significant impact on the behavior of the optical modes in the electromagnetic forbidden bands of the structure. The amplitudes of the defect modes in the transmission and the delay time spectrum, depend strongly on the position of the cavity layer within the photonic crystal. The anisotropic defect layer induces transmission zeros in one of the two components of the transmission as a consequence of a destructive interference of the two polarized waves within this layer, giving rise to negative delay times for some wavelengths in the visible and infrared light ranges. This property is a typical characteristic of the anisotropic photonic layer and is without analogue in their counterpart isotropic defect layers. This structure offers several possibilities for controlling the frequencies, transmitted intensities and the delay times of the optical modes in the visible and infrared regions. It can be a good candidate for realizing high-precision optical filters.

  1. Real-time gigabit DMT transmission over plastic optical fibre

    NARCIS (Netherlands)

    Lee, S.C.J.; Breyer, F.; Cárdenas, D.; Randel, S.; Koonen, A.M.J.

    2009-01-01

    For the first time, a real-time 1.25 Gbit/s discrete multitone (DMT) transmitter implemented in a field-programmable gate array is demonstrated for use in low-cost, standard 1 mm step-index plastic optical fibre applications based on a commercial resonant-cavity LED and a large-diameter

  2. Kansas Communication and Instruction System through Fiber-Optic Transmission.

    Science.gov (United States)

    Kansas State Dept. of Education, Topeka.

    Schools and communities will restructure as they move into the next decade. The success of this restructuring will be dependent upon access to and sharing of quality teaching and information through an expanded communication system. One of the major two-way interactive technologies is the fiber-optic cable: a delivery system that will provide…

  3. Effects of layer nanodefects on the light transmission by optical elements with multilayer interference coatings

    International Nuclear Information System (INIS)

    Fekeshgazyi, Yi.V.; Syidenko, T.S.; Mitsa, O.V.; Barna, P.; Kyikyineshyi, O.Ye.

    2011-01-01

    The light transmission properties of optical elements with multilayer interference coatings have been studied. The reduction of transmittance maxima for optical elements with coating containing defects is found to be stronger for larger refractive indices of the substances that the defects are made of. The shape of transmittance curves is found to substantially depend on the defect dimensions along the direction of light propagation and the defect arrangement in the layer bulk. The results obtained are necessary for the developing of a technology aimed at manufacturing the optical elements with multilayer interference coatings for laser facilities and optical lenses.

  4. Optical stealth transmission based on super-continuum generation in highly nonlinear fiber over WDM network.

    Science.gov (United States)

    Zhu, Huatao; Wang, Rong; Pu, Tao; Fang, Tao; Xiang, Peng; Zheng, Jilin; Chen, Dalei

    2015-06-01

    In this Letter, the optical stealth transmission carried by super-continuum spectrum optical pulses generated in highly nonlinear fiber is proposed and experimentally demonstrated. In the proposed transmission scheme, super-continuum signals are reshaped in the spectral domain through a wavelength-selective switch and are temporally spread by a chromatic dispersion device to achieve the same noise-like characteristic as the noise in optical networks, so that in both the time domain and the spectral domain, the stealth signals are hidden in public channel. Our experimental results show that compared with existing schemes where stealth channels are carried by amplified spontaneous emission noise, super-continuum signal can increase the transmission performance and robustness.

  5. Controlling the optical bistability and transmission coefficient in a four-level atomic medium

    International Nuclear Information System (INIS)

    Asadpour, Seyyed Hossein; Eslami-Majd, Abdullah

    2012-01-01

    A novel four level atomic configuration is proposed for controlling the optical bistability and transmission coefficient with application on all-optical switching. Two circularly polarized components from a weak linearly-polarized probe beam are interacted separately by two transitions of this medium. A coherent coupling field has derived another atomic transition. It is demonstrated that the transmission coefficient of two orthogonally polarized beams at different frequencies can be achieved by adjusting the magnitude of the external magnetic field. It is found that the threshold of the optical bistability can be controlled by magnitude of the external magnetic field. Also, it is shown that optical bistability can be converted to optical multistability by switching the two orthogonally polarized beams. - Highlights: ► An inverted Y-type four level atomic system is proposed. ► Transmission coefficient can be controlled by a novel interesting parameter. ► Optical bistability and multistability can be achieved via external magnetic field. ► It is shown that our proposed model is suitable for all optical switching application.

  6. Polarization mode dispersion in optical fiber transmission systems

    Science.gov (United States)

    Cameron, John Charles

    The birefringence of optical fibers causes pulse broadening in fiber-optic communication systems. This phenomenon is known as polarization mode dispersion (PMD). PMD is one of the most important limiting factors for high capacity fiber-optic systems. A number of aspects of PMD are examined in this thesis. In Chapter 2 an expression is derived for the probability density function of the pulse broadening due to first-order PMD. This result is used to obtain an expression for the system limitation due to PMD. The birefringence of optical fibers is commonly simulated with the waveplate model. In Chapter 3 two standard versions of the waveplate model are introduced. In addition, a novel waveplate model is proposed. The characteristics of the three versions of the waveplate model are examined to confirm their suitability for use in subsequent chapters of the thesis. Simulations with the waveplate model are performed in Chapter 4 for three purposes: (1) to determine the impact of chromatic dispersion on the system limitation due to PMD, (2) to examine the effectiveness of three different PMD compensation techniques in the presence of chromatic dispersion, and (3) to examine the interaction of second-order chromatic dispersion with PMD. The simulations in Chapter 4 reveal that it is possible with one compensation technique to have output pulses that are narrower than the input pulses. In Chapter 5, this anomalous pulse narrowing is demonstrated analytically for a simple model of PMD and through experiment. It is also shown that this pulse narrowing can be explained as an interference phenomenon. Chapter 6 presents measurements of PMD and state of polarization on installed optical fibers. The PMD coefficients of 122 fibers are presented and the results are analyzed in terms of the age of the fibers and the type of cabling. Measurements of the time evolution of PMD and state of polarization are presented for fibers installed in both buried and aerial cables. The uncertainty

  7. Opto-mechanical design for transmission optics in cryogenic space instrumentation

    Science.gov (United States)

    Kroes, Gabby; Venema, Lars; Navarro, Ramón

    2017-11-01

    NOVA is involved in the development and realization of various optical astronomical instruments for groundbased as well as space telescopes, with a focus on nearand mid-infrared instrumentation. NOVA has developed a suite of scientific instruments with cryogenic optics for the ESO VLT and VLTI instruments: VISIR, MIDI, the SPIFFI 2Kcamera for SINFONI, X-shooter and MATISSE. Other projects include the cryogenic optics for MIRI for the James Webb Space Telescope and several E-ELT instruments. Mounting optics is always a compromise between firmly fixing the optics and preventing stresses within the optics. The fixing should ensure mechanical stability and thus accurate positioning in various gravity orientations, temperature ranges, during launch, transport or earthquake. On the other hand, the fixings can induce deformations and sometimes birefringence in the optics and thus cause optical errors. Even cracking or breaking of the optics is a risk, especially when using brittle infrared optical materials at the cryogenic temperatures required in instruments for infrared astronomy, where differential expansion of various materials amounts easily to several millimeters per meter. Special kinematic mounts are therefore needed to ensure both accurate positioning and low stress. This paper concentrates on the opto-mechanical design of optics mountings, especially for large transmission optics in cryogenic circumstances in space instruments. It describes the development of temperature-invariant ("a-thermal") kinematic designs, their implementation in ground based instrumentation and ways to make them suitable for space instruments.

  8. Optical transmission for the James Webb Space Telescope

    Science.gov (United States)

    Lightsey, Paul A.; Gallagher, Benjamin B.; Nickles, Neal; Copp, Tracy

    2012-09-01

    The fabrication and coating of the mirrors for the James Webb Space Telescope has been completed. The spectral reflectivity of the protected gold coated beryllium mirrors has been measured. The predicted end-of-life transmission through the telescope builds from these values. The additional phenomena that have been analyzed are contamination effects and effects of the environment for the JWST operation about the Earth-Sun L2 Lagrange libration point. The L2 environment analysis has been based on radiation testing of mirror samples and hypervelocity testing to assess the micrometeoroid impact effects. The mirror showed no change in reflectance over the VIS-SWIR wavelengths after exposure to 6-9 Grad (Si) that simulated 6 years orbiting the L2 Lagrange point. The effects of hypervelocity particle impacts on the mirrors from test data has been extrapolated to the to the anticipated flux characteristics for micrometeoroids at the L2 environment. The results show that the micrometeoroid effects are orders of magnitude below the particulate contamination effects. The final end-of-life transmission for the mirrors including all of these phenomena will meet the performance requirements for JWST.

  9. Digital Photonic Receivers for Wireless and Wireline Optical Fiber Transmission Links

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil

    services. The experimental demonstration supported the following transmissions systems: a baseband, 5 Gbps, intensity modulation system employing a directly modulated vertical cavity surface emitting laser (VCSEL), a baseband 20 Gbps non-return-to-zero quadrature phase-shift keying (NRZ-QPSK) system...... receivers in hybrid wireless and wireline optical fiber transmission links. Furthermore, the digital signal processing framework presented in this thesis can be extended to design probabilistic-based digital photonic receivers that can find applications in cognitive heterogeneous reconfigurable optical...

  10. Optical transmission modules for multi-channel superconducting quantum interference device readouts

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin-Mok, E-mail: jmkim@kriss.re.kr; Kwon, Hyukchan; Yu, Kwon-kyu; Lee, Yong-Ho; Kim, Kiwoong [Brain Cognition Measurement Center, Korea Research Institute of Standards and Science, Daejeon 305-600 (Korea, Republic of)

    2013-12-15

    We developed an optical transmission module consisting of 16-channel analog-to-digital converter (ADC), digital-noise filter, and one-line serial transmitter, which transferred Superconducting Quantum Interference Device (SQUID) readout data to a computer by a single optical cable. A 16-channel ADC sent out SQUID readouts data with 32-bit serial data of 8-bit channel and 24-bit voltage data at a sample rate of 1.5 kSample/s. A digital-noise filter suppressed digital noises generated by digital clocks to obtain SQUID modulation as large as possible. One-line serial transmitter reformed 32-bit serial data to the modulated data that contained data and clock, and sent them through a single optical cable. When the optical transmission modules were applied to 152-channel SQUID magnetoencephalography system, this system maintained a field noise level of 3 fT/√Hz @ 100 Hz.

  11. The optical transmission characteristics in metallic photonic crystals

    International Nuclear Information System (INIS)

    Aly, Arafa H.; Elsayed, Hussein A.; Hamdy, Hany S.

    2010-01-01

    We theoretically studied electromagnetic wave propagation in a one-dimensional metal/dielectric photonic crystal (1D MDPC) consisting of alternating metallic and dielectric materials by using the transfer matrix method in visible and infrared regions. We have investigated the photonic band gap by using four kinds of metals: silver, lithium, gold and copper. We discuss the details of the calculated results in terms of the thickness of the metallic layer and different kinds of metals, and the plasma frequency. Our results have a potential for applications in optical devices because it is easy and cheap to manufacture.

  12. Optical fiber cable for transmission of high power laser energy over great distances

    Science.gov (United States)

    Zediker, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Moxley, Joel F.; Koblick, Yeshaya

    2016-05-24

    There is provided a system and apparatus for the transmission of high power laser energy over great distances without substantial power loss and without the presence of stimulated Raman scattering. There is further provided systems and optical fiber cable configurations and optical fiber structures for the delivering high power laser energy over great distances to a tool or surface to perform an operation or work with the tool or upon the surface.

  13. Optical fiber configurations for transmission of laser energy over great distances

    Science.gov (United States)

    Rinzler, Charles C; Zediker, Mark S

    2013-10-29

    There are provided optical fiber configurations that provide for the delivery of laser energy, and in particular, the transmission and delivery of high power laser energy over great distances. These configurations further are hardened to protect the optical fibers from the stresses and conditions of an intended application. The configurations provide means for determining the additional fiber length (AFL) need to obtain the benefits of such additional fiber, while avoiding bending losses.

  14. The VTRx+, an optical link module for data transmission at HL-LHC

    CERN Document Server

    Troska, Jan; Detraz, Stephane; Kraxner, Andrea; Olanterä, Lauri; Scarcella, Carmelo; Sigaud, Christophe; Soos, Csaba; Vasey, Francois

    2017-01-01

    Optical data transmission will remain a key enabling technology for the upgrading detectors at HL-LHC. In particular the inner tracking detectors will require low-mass, radiation tolerant optical transmit and receive modules for tight integration in the detector front-ends. We describe the development of such a module, giving details of the design, functional and environmental performance, as well as showing the feasibility of achieving small size, low-mass, and low-power operation.

  15. 160 Gb/s OFDM transmission utilizing an all-optical symbol generator based on PLC

    Science.gov (United States)

    Liang, Xiaojun; Qiao, Yaojun; Li, Wei; Mei, Junyao; Qin, Yi

    2009-11-01

    We demonstrate a 160 Gb/s orthogonal frequency division multiplexing (OFDM) system using an all-optical symbol generator based on planar light circuit (PLC) technology. Excellent bit error rate (BER) is observed after long-distance transmission. The proposed symbol generator fundamentally eliminates the processing speed limits introduced by electronics and is suitable for high integration, making it physically realizable to build high-speed all-optical OFDM systems with a large number of subcarriers.

  16. Gemini/GMOS Transmission Spectral Survey: Complete Optical Transmission Spectrum of the Hot Jupiter WASP-4b

    Energy Technology Data Exchange (ETDEWEB)

    Huitson, C. M. [CASA, University of Colorado, 389 UCB, Boulder, CO 80309-0389 (United States); Désert, J.-M. [API, University of Amsterdam, P.O. Box 94249, 1090 GE Amsterdam (Netherlands); Bean, J. L. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Fortney, J. J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Stevenson, K. B. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Bergmann, M., E-mail: catherine.huitson@colorado.edu [NOAO and Gemini Observatory, present address Palo Alto, CA (United States)

    2017-09-01

    We present the complete optical transmission spectrum of the hot Jupiter WASP-4b from 440 to 940 nm at R  ∼ 400–1500 obtained with the Gemini Multi-Object Spectrometers (GMOS); this is the first result from a comparative exoplanetology survey program of close-in gas giants conducted with GMOS. WASP-4b has an equilibrium temperature of 1700 K and is favorable to study in transmission due to its large scale height (370 km). We derive the transmission spectrum of WASP-4b using four transits observed with the MOS technique. We demonstrate repeatable results across multiple epochs with GMOS, and derive a combined transmission spectrum at a precision about twice above photon noise, which is roughly equal to one atmospheric scale height. The transmission spectrum is well fitted with a uniform opacity as a function of wavelength. The uniform opacity and absence of a Rayleigh slope from molecular hydrogen suggest that the atmosphere is dominated by clouds with condensate grain sizes of ∼1  μ m. This result is consistent with previous observations of hot Jupiters since clouds have been seen in planets with similar equilibrium temperatures to WASP-4b. We describe a custom pipeline that we have written to reduce GMOS time-series data of exoplanet transits, and present a thorough analysis of the dominant noise sources in GMOS, which primarily consist of wavelength- and time-dependent displacements of the spectra on the detector, mainly due to a lack of atmospheric dispersion correction.

  17. Gemini/GMOS Transmission Spectral Survey: Complete Optical Transmission Spectrum of the Hot Jupiter WASP-4b

    International Nuclear Information System (INIS)

    Huitson, C. M.; Désert, J.-M.; Bean, J. L.; Fortney, J. J.; Stevenson, K. B.; Bergmann, M.

    2017-01-01

    We present the complete optical transmission spectrum of the hot Jupiter WASP-4b from 440 to 940 nm at R  ∼ 400–1500 obtained with the Gemini Multi-Object Spectrometers (GMOS); this is the first result from a comparative exoplanetology survey program of close-in gas giants conducted with GMOS. WASP-4b has an equilibrium temperature of 1700 K and is favorable to study in transmission due to its large scale height (370 km). We derive the transmission spectrum of WASP-4b using four transits observed with the MOS technique. We demonstrate repeatable results across multiple epochs with GMOS, and derive a combined transmission spectrum at a precision about twice above photon noise, which is roughly equal to one atmospheric scale height. The transmission spectrum is well fitted with a uniform opacity as a function of wavelength. The uniform opacity and absence of a Rayleigh slope from molecular hydrogen suggest that the atmosphere is dominated by clouds with condensate grain sizes of ∼1  μ m. This result is consistent with previous observations of hot Jupiters since clouds have been seen in planets with similar equilibrium temperatures to WASP-4b. We describe a custom pipeline that we have written to reduce GMOS time-series data of exoplanet transits, and present a thorough analysis of the dominant noise sources in GMOS, which primarily consist of wavelength- and time-dependent displacements of the spectra on the detector, mainly due to a lack of atmospheric dispersion correction.

  18. Hardware authentication using transmission spectra modified optical fiber

    International Nuclear Information System (INIS)

    Grubbs, Robert K.; Romero, Juan A.

    2010-01-01

    The ability to authenticate the source and integrity of data is critical to the monitoring and inspection of special nuclear materials, including hardware related to weapons production. Current methods rely on electronic encryption/authentication codes housed in monitoring devices. This always invites the question of implementation and protection of authentication information in an electronic component necessitating EMI shielding, possibly an on board power source to maintain the information in memory. By using atomic layer deposition techniques (ALD) on photonic band gap (PBG) optical fibers we will explore the potential to randomly manipulate the output spectrum and intensity of an input light source. This randomization could produce unique signatures authenticating devices with the potential to authenticate data. An external light source projected through the fiber with a spectrometer at the exit would 'read' the unique signature. No internal power or computational resources would be required.

  19. Robust transmission of non-Gaussian entanglement over optical fibers

    International Nuclear Information System (INIS)

    Biswas, Asoka; Lidar, Daniel A.

    2006-01-01

    We show how the entanglement in a wide range of continuous variable non-Gaussian states can be preserved against decoherence for long-range quantum communication through an optical fiber. We apply protection via decoherence-free subspaces and quantum dynamical decoupling to this end. The latter is implemented by inserting phase shifters at regular intervals Δ inside the fiber, where Δ is roughly the ratio of the speed of light in the fiber to the bath high-frequency cutoff. Detailed estimates of relevant parameters are provided using the boson-boson model of system-bath interaction for silica fibers and Δ is found to be on the order of a millimeter

  20. Power-efficient method for IM-DD optical transmission of multiple OFDM signals.

    Science.gov (United States)

    Effenberger, Frank; Liu, Xiang

    2015-05-18

    We propose a power-efficient method for transmitting multiple frequency-division multiplexed (FDM) orthogonal frequency-division multiplexing (OFDM) signals in intensity-modulation direct-detection (IM-DD) optical systems. This method is based on quadratic soft clipping in combination with odd-only channel mapping. We show, both analytically and experimentally, that the proposed approach is capable of improving the power efficiency by about 3 dB as compared to conventional FDM OFDM signals under practical bias conditions, making it a viable solution in applications such as optical fiber-wireless integrated systems where both IM-DD optical transmission and OFDM signaling are important.

  1. Experimental demonstration of optical stealth transmission over wavelength-division multiplexing network.

    Science.gov (United States)

    Zhu, Huatao; Wang, Rong; Pu, Tao; Fang, Tao; Xiang, Peng; Zheng, Jilin; Tang, Yeteng; Chen, Dalei

    2016-08-10

    We propose and experimentally demonstrate an optical stealth transmission system over a 200 GHz-grid wavelength-division multiplexing (WDM) network. The stealth signal is processed by spectral broadening, temporal spreading, and power equalizing. The public signal is suppressed by multiband notch filtering at the stealth channel receiver. The interaction between the public and stealth channels is investigated in terms of public-signal-to-stealth-signal ratio, data rate, notch-filter bandwidth, and public channel number. The stealth signal can transmit over 80 km single-mode fiber with no error. Our experimental results verify the feasibility of optical steganography used over the existing WDM-based optical network.

  2. Transmission performance of a 400 Gbit s−1 all-optical orthogonal frequency division multiplexing system

    International Nuclear Information System (INIS)

    Tang, Jing; Xia, Min; Li, Wei; Yang, Kecheng; Liu, Deming; Huang, Benxiong

    2013-01-01

    The performance of a 400 Gbit s −1 all-optical orthogonal frequency division multiplexing (AO-OFDM) transmission system is researched with the effects of chromatic dispersion, fiber nonlinearities and amplified spontaneous emission (ASE) noise. The numerical simulation results show that the AO-OFDM system can provide a higher spectral efficiency (SE) and a better sensitivity than a dense wavelength division multiplexing (DWDM) system. The accumulated dispersion tolerance of the system reaches 330 ps nm −1 . When transmitted over single-span 80 km single-mode fiber (SMF), AO-OFDM signals have a 1.5 dB power penalty at BER=10 −3 due to the fiber Kerr nonlinearities, and the receiver sensitivity of the AO-OFDM system is obviously degraded with increasing incident optical power. In multispan transmission, the interaction of the fiber Kerr nonlinearity with the ASE noise is analyzed. A 1320 km maximum transmission distance is realized at 0 dBm incident optical power. The transmission discount due to the ASE noise and fiber nonlinearities in the AO-OFDM system is calculated. Fiber Kerr nonlinearities impose a greater limitation on the performance of the AO-OFDM system for long-distance transmission. All results clearly indicate the feasibility of AO-OFDM technology for next generation 400 Gbit s −1 fiber communication and multiservice networks. (paper)

  3. Advanced spectral processing of broadband light using acousto-optic devices with arbitrary transmission functions.

    Science.gov (United States)

    Molchanov, Vladimir Ya; Yushkov, Konstantin B

    2014-06-30

    In the paper, we developed a dispersive method for transmission function synthesis of collinear and quasi-collinear acousto-optic tunable filters. General theoretical consideration was performed, and modelling was made for broadband and narrowband signals. Experimental results on spectral shaping of femtosecond laser emission were obtained. Binary spectral encoding of broadband emission was demonstrated.

  4. Optical modeling of fiber organic photovoltaic structures using a transmission line method.

    Science.gov (United States)

    Moshonas, N; Stathopoulos, N A; O'Connor, B T; Bedeloglu, A Celik; Savaidis, S P; Vasiliadis, S

    2017-12-01

    An optical model has been developed and evaluated for the calculation of the external quantum efficiency of cylindrical fiber photovoltaic structures. The model is based on the transmission line theory and has been applied on single and bulk heterojunction fiber-photovoltaic cells. Using this model, optimum design characteristics have been proposed for both configurations, and comparison with experimental results has been assessed.

  5. 1.28 Tbaud Nyquist Signal Transmission using Time-Domain Optical Fourier Transformation based Receiver

    DEFF Research Database (Denmark)

    Hu, Hao; Kong, Deming; Palushani, Evarist

    2013-01-01

    We demonstrate transmission of a 1.28-Tbaud Nyquist-OTDM signal over a record distance of 100 km with detection by time-domain optical Fourier transformation followed by FEC decoding, resulting in error-free performance for all tributaries....

  6. Modeling optical transmissivity of graphene grate in on-chip silicon photonic device

    Directory of Open Access Journals (Sweden)

    Iraj S. Amiri

    2018-06-01

    Full Text Available A three-dimensional (3-D finite-difference-time-domain (FDTD analysis was used to simulate a silicon photonic waveguide. We have calculated power and transmission of the graphene used as single or multilayers to study the light transmission behavior. A new technique has been developed to define the straight silicon waveguide integrated with grate graphene layer. The waveguide has a variable grate spacing to be filled by the graphene layer. The number of graphene atomic layers varies between 100 and 1000 (or 380 nm and 3800 nm, the transmitted power obtained varies as ∼30% and ∼80%. The ∼99%, blocking of the light was occurred in 10,000 (or 38,000 nm atomic layers of the graphene grate. Keywords: Optical waveguide, Silicon waveguide, Grate, Graphene, Optical transmissivity

  7. Coherent optical DFT-spread OFDM transmission using orthogonal band multiplexing.

    Science.gov (United States)

    Yang, Qi; He, Zhixue; Yang, Zhu; Yu, Shaohua; Yi, Xingwen; Shieh, William

    2012-01-30

    Coherent optical OFDM (CO-OFDM) combined with orthogonal band multiplexing provides a scalable and flexible solution for achieving ultra high-speed rate. Among many CO-OFDM implementations, digital Fourier transform spread (DFT-S) CO-OFDM is proposed to mitigate fiber nonlinearity in long-haul transmission. In this paper, we first illustrate the principle of DFT-S OFDM. We then experimentally evaluate the performance of coherent optical DFT-S OFDM in a band-multiplexed transmission system. Compared with conventional clipping methods, DFT-S OFDM can reduce the OFDM peak-to-average power ratio (PAPR) value without suffering from the interference of the neighboring bands. With the benefit of much reduced PAPR, we successfully demonstrate 1.45 Tb/s DFT-S OFDM over 480 km SSMF transmission.

  8. Unidirectional transmission in 1D nonlinear photonic crystal based on topological phase reversal by optical nonlinearity

    Directory of Open Access Journals (Sweden)

    Chong Li

    2017-02-01

    Full Text Available We propose a scheme of unidirectional transmission in a 1D nonlinear topological photonic crystal based on the topological edge state and three order optical nonlinearity. The 1D photonic crystals consists of a nonlinear photonic crystal L and a linear photonic crystal R. In the backward direction, light is totally reflected for the photons transmission prohibited by the bandgap. While in the forward direction, light interacts with the nonlinear photonic crystal L by optical Kerr effect, bringing a topological phase reversal and results the topological edge mode arising at the interface which could transmit photons through the bandgaps both of the photonic crystal L and R. When the signal power intensity larger than a moderate low threshold value of 10.0 MW/cm2, the transmission contrast ratio could remain at 30 steadily.

  9. Design of free-space optical transmission system in computer tomography equipment

    Science.gov (United States)

    Liu, Min; Fu, Weiwei; Zhang, Tao

    2018-04-01

    Traditional computer tomography (CT) based on capacitive coupling cannot satisfy the high data rate transmission requirement. We design and experimentally demonstrate a free-space optical transmission system for CT equipment at a data rate of 10 Gb / s. Two interchangeable sections of 12 pieces of fiber with equal length is fabricated and tested by our designed laser phase distance measurement system. By locating the 12 collimators in the edge of the circle wheel evenly, the optical propagation characteristics for the 12 wired and wireless paths are similar, which can satisfy the requirement of high-speed CT transmission system. After bit error rate (BER) measurement in several conditions, the BER performances are below the value of 10 - 11, which has the potential in the future application scenario of CT equipment.

  10. 47 CFR 32.7600 - Extraordinary items.

    Science.gov (United States)

    2010-10-01

    ... FOR TELECOMMUNICATIONS COMPANIES Instructions For Other Income Accounts § 32.7600 Extraordinary items... extraordinary. Extraordinary events and transactions are distinguished by both their unusual nature and by the infrequency of their occurrence, taking into account the environment in which the company operates. This...

  11. Simulation and Noise Analysis of Multimedia Transmission in Optical CDMA Computer Networks

    Directory of Open Access Journals (Sweden)

    Nasaruddin Nasaruddin

    2013-09-01

    Full Text Available This paper simulates and analyzes noise of multimedia transmission in a flexible optical code division multiple access (OCDMA computer network with different quality of service (QoS requirements. To achieve multimedia transmission in OCDMA, we have proposed strict variable-weight optical orthogonal codes (VW-OOCs, which can guarantee the smallest correlation value of one by the optimal design. In developing multimedia transmission for computer network, a simulation tool is essential in analyzing the effectiveness of various transmissions of services. In this paper, implementation models are proposed to analyze the multimedia transmission in the representative of OCDMA computer networks by using MATLAB simulink tools. Simulation results of the models are discussed including spectrums outputs of transmitted signals, superimposed signals, received signals, and eye diagrams with and without noise. Using the proposed models, multimedia OCDMA computer network using the strict VW-OOC is practically evaluated. Furthermore, system performance is also evaluated by considering avalanche photodiode (APD noise and thermal noise. The results show that the system performance depends on code weight, received laser power, APD noise, and thermal noise which should be considered as important parameters to design and implement multimedia transmission in OCDMA computer networks.

  12. Simulation and Noise Analysis of Multimedia Transmission in Optical CDMA Computer Networks

    Directory of Open Access Journals (Sweden)

    Nasaruddin

    2009-11-01

    Full Text Available This paper simulates and analyzes noise of multimedia transmission in a flexible optical code division multiple access (OCDMA computer network with different quality of service (QoS requirements. To achieve multimedia transmission in OCDMA, we have proposed strict variable-weight optical orthogonal codes (VW-OOCs, which can guarantee the smallest correlation value of one by the optimal design. In developing multimedia transmission for computer network, a simulation tool is essential in analyzing the effectiveness of various transmissions of services. In this paper, implementation models are proposed to analyze the multimedia transmission in the representative of OCDMA computer networks by using MATLAB simulink tools. Simulation results of the models are discussed including spectrums outputs of transmitted signals, superimposed signals, received signals, and eye diagrams with and without noise. Using the proposed models, multimedia OCDMA computer network using the strict VW-OOC is practically evaluated. Furthermore, system performance is also evaluated by considering avalanche photodiode (APD noise and thermal noise. The results show that the system performance depends on code weight, received laser power, APD noise, and thermal noise which should be considered as important parameters to design and implement multimedia transmission in OCDMA computer networks.

  13. Data transmission optical link for LLRF TESLA project part I: hardware structure of OPT0 module

    Science.gov (United States)

    Pozniak, Krzysztof T.; Romaniuk, Ryszard S.; Jalmuzna, Wojciech; Olowski, Krzysztof; Perkuszewski, Karol; Zielinski, Jerzy; Kierzkowski, Krzysztof

    2006-03-01

    It may be predicted now, even assuming a very conservative approach, that the next generation of the Low Level RF control systems for future accelerators will use extensively such technologies like: very fast programmable circuits equipped with DSP, embedded PC and optical communication I/O functionalities, as well as multi-gigabit optical transmission of measurement data and control signals. The paper presents the idea and realization of a gigabit synchronous data distributor designed to work in the LLRF control system of TESLA technology based X-ray FEL. The design bases on a relatively simple and cheap FPGA chip Cyclone. Commercially available SERDES (serializer/deserializer) and optical transceiver chips were applied. The optoelectronic module is embedded on the main LLRF BMB (backbone mother board). The MB provides communication with the outside computer control system, programmable chip configuration, integration with other functional modules and power supply. The hardware implementation is here described and the used software for BER (bit-error-rate) testing of the multi-gigabit optical link. The measurement results are presented. The appendix contains a comparison between the available protocols of serial data transmission for FPGA technology. This paper is a partial contribution to the next version of the SIMCON system which is expected to be released this year. The SIMCON, ver 3.0 will contain 8 channels and multi-gigabit optical transmission capability. It will be a fully modular construction.

  14. An Exploration of Professional Culture Differentials and Their Potential Impact on the Information Assurance Component of Optical Transmission Networks Design

    Science.gov (United States)

    Cuthrell, Michael Gerard

    2011-01-01

    Optical transmission networks are an integral component of the critical infrastructures for many nations. Many people believe that optical transmission networks are impenetrable. In actuality, these networks possess weaknesses that can be exploited to bring about harm. An emerging Information Assurance (IA) industry has as its goals: to…

  15. Optical frequency upconversion technique for transmission of wireless MIMO-type signals over optical fiber.

    Science.gov (United States)

    Shaddad, R Q; Mohammad, A B; Al-Gailani, S A; Al-Hetar, A M

    2014-01-01

    The optical fiber is well adapted to pass multiple wireless signals having different carrier frequencies by using radio-over-fiber (ROF) technique. However, multiple wireless signals which have the same carrier frequency cannot propagate over a single optical fiber, such as wireless multi-input multi-output (MIMO) signals feeding multiple antennas in the fiber wireless (FiWi) system. A novel optical frequency upconversion (OFU) technique is proposed to solve this problem. In this paper, the novel OFU approach is used to transmit three wireless MIMO signals over a 20 km standard single mode fiber (SMF). The OFU technique exploits one optical source to produce multiple wavelengths by delivering it to a LiNbO3 external optical modulator. The wireless MIMO signals are then modulated by LiNbO3 optical intensity modulators separately using the generated optical carriers from the OFU process. These modulators use the optical single-sideband with carrier (OSSB+C) modulation scheme to optimize the system performance against the fiber dispersion effect. Each wireless MIMO signal is with a 2.4 GHz or 5 GHz carrier frequency, 1 Gb/s data rate, and 16-quadrature amplitude modulation (QAM). The crosstalk between the wireless MIMO signals is highly suppressed, since each wireless MIMO signal is carried on a specific optical wavelength.

  16. Optimisation of optical receiver for 10 Gbit/s optical duobinary transmission system

    DEFF Research Database (Denmark)

    Zheng, Xueyan; Liu, Fenghai; Jeppesen, Palle

    2001-01-01

    Optimisation of a receiver for an optical duobinary signal is studied numerically. It is shown that a conventional receiver is not optimum neither when a DCF is used before the receiver nor without a DCF being used. The optimum receiver for an optical duobinary system is identified.......Optimisation of a receiver for an optical duobinary signal is studied numerically. It is shown that a conventional receiver is not optimum neither when a DCF is used before the receiver nor without a DCF being used. The optimum receiver for an optical duobinary system is identified....

  17. Image transmission in mid-IR using a solid state laser pumped optical parametric oscillator

    Science.gov (United States)

    Prasad, Narasimha S.; Kratovil, Pat; Magee, James R.

    2002-04-01

    In this paper, image transmission using a mid-wave IR (MWIR) optical transceiver based free-space data link under low visibility conditions is presented. The all-solid-state MWIR transceiver primarily consisted of a passively Q-switched, short-pulsed Nd:YAG laser pumping a periodically poled lithium niobate (PPLN) based optical parametric oscillator and a Dember effect detector. The MILES transceiver generates pulse position waveforms. The optical data link consisting of transmitter drive electronics, pulse conditioning electronics and a computer generating pulses compatible with the 2400-baud rate RS232 receiver was utilized. Data formatting and RS232 transmission and reception were achieved using a computer. Data formatting transformed an arbitrary image file format compatible with the basic operation of pump laser. Images were transmitted at a date rate of 2400 kbits/sec with 16 bits/pixel. Test images consisting of 50X40 pixels and 100X80 pixels were transmitted through free-space filled with light fog up to 120 ft. Besides optical parametric oscillators, the proposed concept can be extended to optical parametric amplifiers, Raman lasers and other nonlinear optical devices to achieve multi-functionality.

  18. Analysis of Optical CDMA Signal Transmission: Capacity Limits and Simulation Results

    Directory of Open Access Journals (Sweden)

    Lawrence R. Chen

    2005-06-01

    Full Text Available We present performance limits of the optical code-division multiple-access (OCDMA networks. In particular, we evaluate the information-theoretical capacity of the OCDMA transmission when single-user detection (SUD is used by the receiver. First, we model the OCDMA transmission as a discrete memoryless channel, evaluate its capacity when binary modulation is used in the interference-limited (noiseless case, and extend this analysis to the case when additive white Gaussian noise (AWGN is corrupting the received signals. Next, we analyze the benefits of using nonbinary signaling for increasing the throughput of optical CDMA transmission. It turns out that up to a fourfold increase in the network throughput can be achieved with practical numbers of modulation levels in comparison to the traditionally considered binary case. Finally, we present BER simulation results for channel coded binary and M-ary OCDMA transmission systems. In particular, we apply turbo codes concatenated with Reed-Solomon codes so that up to several hundred concurrent optical CDMA users can be supported at low target bit error rates. We observe that unlike conventional OCDMA systems, turbo-empowered OCDMA can allow overloading (more active users than is the length of the spreading sequences with good bit error rate system performance.

  19. Analysis of Optical CDMA Signal Transmission: Capacity Limits and Simulation Results

    Science.gov (United States)

    Garba, Aminata A.; Yim, Raymond M. H.; Bajcsy, Jan; Chen, Lawrence R.

    2005-12-01

    We present performance limits of the optical code-division multiple-access (OCDMA) networks. In particular, we evaluate the information-theoretical capacity of the OCDMA transmission when single-user detection (SUD) is used by the receiver. First, we model the OCDMA transmission as a discrete memoryless channel, evaluate its capacity when binary modulation is used in the interference-limited (noiseless) case, and extend this analysis to the case when additive white Gaussian noise (AWGN) is corrupting the received signals. Next, we analyze the benefits of using nonbinary signaling for increasing the throughput of optical CDMA transmission. It turns out that up to a fourfold increase in the network throughput can be achieved with practical numbers of modulation levels in comparison to the traditionally considered binary case. Finally, we present BER simulation results for channel coded binary and[InlineEquation not available: see fulltext.]-ary OCDMA transmission systems. In particular, we apply turbo codes concatenated with Reed-Solomon codes so that up to several hundred concurrent optical CDMA users can be supported at low target bit error rates. We observe that unlike conventional OCDMA systems, turbo-empowered OCDMA can allow overloading (more active users than is the length of the spreading sequences) with good bit error rate system performance.

  20. On the optical stability of high-resolution transmission electron microscopes

    International Nuclear Information System (INIS)

    Barthel, J.; Thust, A.

    2013-01-01

    In the recent two decades the technique of high-resolution transmission electron microscopy experienced an unprecedented progress through the introduction of hardware aberration correctors and by the improvement of the achievable resolution to the sub-Ångström level. The important aspect that aberration correction at a given resolution requires also a well defined amount of optical stability has received little attention so far. Therefore we investigate the qualification of a variety of high-resolution electron microscopes to maintain an aberration corrected optical state in terms of an optical lifetime. We develop a comprehensive statistical framework for the estimation of the optical lifetime and find remarkably low values between tens of seconds and a couple of minutes. Probability curves are introduced, which inform the operator about the chance to work still in the fully aberration corrected state. - Highlights: • We investigate the temporal stability of optical aberrations in HRTEM. • We develop a statistical framework for the estimation of optical lifetimes. • We introduce plots showing the success probability for aberration-free work. • Optical lifetimes in sub-Ångström electron microscopy are surprisingly low. • The success of aberration correction depends strongly on the optical stability

  1. New Ideas: Ordinary is Extraordinary

    Directory of Open Access Journals (Sweden)

    Antonio Jose

    2004-06-01

    Full Text Available Abstract With the initial issue of this journal, a new challenge has been offered tothe world of sports nutrition: initiate "team oriented" research and clinical trials in order to make dynamic progress in terms of understandingand applying nutrition principals to the field of competitive sports. It is our further challenge that these teams think "outside the box" in terms of their approach to elucidating new concepts through which nutritional interventions might play a role in the regulation of muscle growth and repair, athletic performance and endurance, and mental acuity. What was once thought of as extraordinary might now be approached as ordinary, if the correct composition of "teams" were formed.

  2. Light propagation and transmission in hybrid-aligned nematic liquid crystal cells: Geometrical optics calculations

    Science.gov (United States)

    Mendoza, Carlos I.; Reyes, J. Adrian

    2006-08-01

    The authors present a geometrical approach to calculate the transmission of light in a hybrid-aligned nematic cell under the influence of an applied electric field. Using the framework of geometrical optics they present results for the ray tracing as well as the transmission of light as a function of the applied low frequency voltage. Dispersion effects are included through a wavelength dependent dielectric function. Their results for the transmittance as a function of the applied voltage show oscillations that are in good qualitative agreement with previously obtained experimental measurements.

  3. On the possibility of developing incoherent fibre-optic data transmission systems based on signal spectral coding with matched acousto-optical filters

    International Nuclear Information System (INIS)

    Proklov, Valerii V; Byshevski-Konopko, O A; Grigorievski, V I

    2013-01-01

    The scheme is suggested for developing the optical communication line based on the principle of code division of multiple access with matched acousto-optical filters and a 16-bit long Walsh sequence. Results of modelling show that such a line can operate if adjacent spectral lines are separated by at least double the Rayleigh criterion. (optical information transmission)

  4. 38.2-Gb/s Optical-Wireless Transmission in 75-110 GHz Based on Electrical OFDM with Optical Comb Expansion

    DEFF Research Database (Denmark)

    Deng, Lei; Pang, Xiaodan; Beltrán, Marta

    2012-01-01

    We demonstrate scalable optical comb- and heterodyning-based generation, optical and 1.3-m wireless transmission, and electrical heterodyne detection of multiband OFDM up to 38.2 Gb/s occupying 14.4-GHz RF bandwidth, for high-capacity optical-wireless links in 75-110 GHz....

  5. Experimental demonstration of a cognitive quality of transmission estimator for optical communication systems

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Aguado, Juan Carlos; Borkowski, Robert

    2012-01-01

    small and not optimized underlying knowledge base, it achieves between 79% and 98.7% successful classifications based on the error vector magnitude (EVM) parameter, and approximately 100% when the classification is based on the optical signal to noise ratio (OSNR).......The impact of physical layer impairments in optical network design and operation has received significant attention in the last years, thereby requiring estimation techniques to predict the quality of transmission (QoT) of optical connections before being established. In this paper, we report...... on the experimental demonstration of a case-based reasoning (CBR) technique to predict whether optical channels fulfill QoT requirements, thus supporting impairment-aware networking. The validation of the cognitive QoT estimator is performed in a WDM 80 Gb/s PDM-QPSK testbed, and we demonstrate that even with a very...

  6. APPLIED OPTICS. Overcoming Kerr-induced capacity limit in optical fiber transmission.

    Science.gov (United States)

    Temprana, E; Myslivets, E; Kuo, B P-P; Liu, L; Ataie, V; Alic, N; Radic, S

    2015-06-26

    Nonlinear optical response of silica imposes a fundamental limit on the information transfer capacity in optical fibers. Communication beyond this limit requires higher signal power and suppression of nonlinear distortions to prevent irreversible information loss. The nonlinear interaction in silica is a deterministic phenomenon that can, in principle, be completely reversed. However, attempts to remove the effects of nonlinear propagation have led to only modest improvements, and the precise physical mechanism preventing nonlinear cancellation remains unknown. We demonstrate that optical carrier stability plays a critical role in canceling Kerr-induced distortions and that nonlinear wave interaction in silica can be substantially reverted if optical carriers possess a sufficient degree of mutual coherence. These measurements indicate that fiber information capacity can be notably increased over previous estimates. Copyright © 2015, American Association for the Advancement of Science.

  7. Ultra high speed optical transmission using subcarrier-multiplexed four-dimensional LDPC-coded modulation.

    Science.gov (United States)

    Batshon, Hussam G; Djordjevic, Ivan; Schmidt, Ted

    2010-09-13

    We propose a subcarrier-multiplexed four-dimensional LDPC bit-interleaved coded modulation scheme that is capable of achieving beyond 480 Gb/s single-channel transmission rate over optical channels. Subcarrier-multiplexed four-dimensional LDPC coded modulation scheme outperforms the corresponding dual polarization schemes by up to 4.6 dB in OSNR at BER 10(-8).

  8. Full-field transmission-type angle-deviation optical microscope with reflectivity-height transformation.

    Science.gov (United States)

    Chiu, Ming-Hung; Tan, Chen-Tai; Tsai, Ming-Hung; Yang, Ya-Hsin

    2015-10-01

    This full-field transmission-type three-dimensional (3D) optical microscope is constructed based on the angle deviation method (ADM) and the algorithm of reflectivity-height transformation (RHT). The surface height is proportional to the deviation angle of light passing through the object. The angle deviation and surface height can be measured based on the reflectivity closed to the critical angle using a parallelogram prism and two CCDs.

  9. [Correction of light refraction and reflection in medical transmission optical tomography].

    Science.gov (United States)

    Tereshchenko, S A; Potapov, D A

    2002-01-01

    The effects of light refraction and reflection on the quality of image reconstruction in medical transmission optical tomography of high-scattering media are considered. It has been first noted that light refraction not only distorts the geometric scheme of measurements, but may lead to the appearance of object areas that cannot be scanned. Some ways of decreasing the effect of refraction on the reconstruction of spatial distribution of the extinction coefficient are stated.

  10. Self-error-rejecting photonic qubit transmission in polarization-spatial modes with linear optical elements

    Science.gov (United States)

    Jiang, YuXiao; Guo, PengLiang; Gao, ChengYan; Wang, HaiBo; Alzahrani, Faris; Hobiny, Aatef; Deng, FuGuo

    2017-12-01

    We present an original self-error-rejecting photonic qubit transmission scheme for both the polarization and spatial states of photon systems transmitted over collective noise channels. In our scheme, we use simple linear-optical elements, including half-wave plates, 50:50 beam splitters, and polarization beam splitters, to convert spatial-polarization modes into different time bins. By using postselection in different time bins, the success probability of obtaining the uncorrupted states approaches 1/4 for single-photon transmission, which is not influenced by the coefficients of noisy channels. Our self-error-rejecting transmission scheme can be generalized to hyperentangled n-photon systems and is useful in practical high-capacity quantum communications with photon systems in two degrees of freedom.

  11. Towards development of a fiber optic-based transmission monitoring system

    Science.gov (United States)

    Baldwin, Chris S.; Kiddy, Jason S.; Samuel, Paul D.

    2011-06-01

    There is interest in the rotorcraft community to develop health monitoring technologies. Among these technologies is the ability to monitor the transmission planetary gear system. The gearbox environment does not lend itself to traditional sensing technologies due to the harsh environment and crowed space. Traditional vibration-based diagnostics are based on the output from externally mounted sensors, usually accelerometers fixed to the gearbox exterior. This type of system relies on the ability of the vibration signal to travel from the gears through the gearbox housing. These sensors are also susceptible to other interference including electrical magnetic interference (EMI). For these reasons, the development of a fiber optic-based transmission monitoring system represents an appealing alternative to the accelerometer due to their resistance to EMI and other signal corrupting influences. Aither Engineering has been working on integrating the fiber optic sensors into the gearbox environment to measure strain on the ring gear of the planetary gear system. This application utilizes a serial array of wavelength division multiplexed fiber Bragg grating (FBG) sensors. Work in this area has been conducted at both the University of Maryland, College Park and more recently at the NASA Glenn Research Center (NGRC) OH-58 transmission test rig facility. This paper discusses some of the testing results collected from the fiber optic ring gear sensor array. Based on these results, recommendations for system requirements are addressed in terms of the capabilities of the FBG instrumentation.

  12. Frequency-addressed tunable transmission in optically thin metallic nanohole arrays with dual-frequency liquid crystals

    International Nuclear Information System (INIS)

    Hao Qingzhen; Zhao Yanhui; Juluri, Bala Krishna; Kiraly, Brian; Huang, Tony Jun; Liou, Justin; Khoo, Iam Choon

    2011-01-01

    Frequency-addressed tunable transmission is demonstrated in optically thin metallic nanohole arrays embedded in dual-frequency liquid crystals (DFLCs). The optical properties of the composite system are characterized by the transmission spectra of the nanoholes, and a prominent transmission peak is shown to originate from the resonance of localized surface plasmons at the edges of the nanoholes. An ∼17 nm shift in the transmission peak is observed between the two alignment configurations of the liquid crystals. This DFLC-based active plasmonic system demonstrates excellent frequency-dependent switching behavior and could be useful in future nanophotonic applications.

  13. All-optical delay technique for supporting multiple antennas in a hybrid optical - wireless transmission system

    DEFF Research Database (Denmark)

    Prince, Kamau; Chiuchiarelli, A; Presi, M

    2008-01-01

    We introduce a novel continuously-variable optical delay technique to support beam-forming wireless communications systems using antenna arrays. We demonstrate delay with 64-QAM modulated signals at a rate of 15 Msymbol/sec with 2.5 GHz carrier frequency.......We introduce a novel continuously-variable optical delay technique to support beam-forming wireless communications systems using antenna arrays. We demonstrate delay with 64-QAM modulated signals at a rate of 15 Msymbol/sec with 2.5 GHz carrier frequency....

  14. Analysis method of beam pointing stability based on optical transmission matrix

    Science.gov (United States)

    Wang, Chuanchuan; Huang, PingXian; Li, Xiaotong; Cen, Zhaofen

    2016-10-01

    Quite a lot of factors will make effects on beam pointing stability of an optical system, Among them, the element tolerance is one of the most important and common factors. In some large laser systems, it will make final micro beams spot on the image plane deviate obviously. So it is essential for us to achieve effective and accurate analysis theoretically on element tolerance. In order to make the analysis of beam pointing stability convenient and theoretical, we consider transmission of a single chief ray rather than beams approximately to stand for the whole spot deviation. According to optical matrix, we also simplify this complex process of light transmission to multiplication of many matrices. So that we can set up element tolerance model, namely having mathematical expression to illustrate spot deviation in an optical system with element tolerance. In this way, we can realize quantitative analysis of beam pointing stability theoretically. In second half of the paper, we design an experiment to get the spot deviation in a multipass optical system caused by element tolerance, then we adjust the tolerance step by step and compare the results with the datum got from tolerance model, finally prove the correction of tolerance model successfully.

  15. Development of laser surface cladding through energy transmission over optical fiber

    International Nuclear Information System (INIS)

    Hirano, Kenji; Morishige, Norio; Irisawa, Toshio

    1990-01-01

    Much attention has recently been paid to laser cladding techniques as an approach in controlling the composition and structure of the metal surface. If YAG laser is used as the cladding method, the flexibility of laser cladding process increases extremely because YAG laser beam is transmitted through an optical fiber, and enabling cladding on pipes installed in actual plants. So experiments on YAG laser cladding through energy transmission over an optical fiber were performed to prevent stress corrosion cracking in austenitic stainless steel pipes. In order to build a cladding layer, mixed metal powder were pre-placed on the inner surface of the pipe using organic binder and the pre-placed powder beds were melted with YAG laser beam transmitted using an optical fiber. This paper introduces the method of building a cladding layer on pipes in actual nuclear plants. (author)

  16. Optical depth sectioning in the aberration-corrected scanning transmission and scanning confocal electron microscope

    International Nuclear Information System (INIS)

    Behan, G; Nellist, P D

    2008-01-01

    The use of spherical aberration correctors in the scanning transmission electron microscope (STEM) has the effect of reducing the depth of field of the microscope, making three-dimensional imaging of a specimen possible by optical sectioning. Depth resolution can be improved further by placing aberration correctors and lenses pre and post specimen to achieve an imaging mode known as scanning confocal electron microscopy (SCEM). We present the calculated incoherent point spread functions (PSF) and optical transfer functions (OTF) of a STEM and SCEM. The OTF for a STEM is shown to have a missing cone region which results in severe blurring along the optic axis, which can be especially severe for extended objects. We also present strategies for reconstruction of experimental data, such as three-dimensional deconvolution of the point spread function.

  17. Biological Applications of Extraordinary Electroconductance and Photovoltaic Effects in Inverse Extraordinary Optoconductance

    Science.gov (United States)

    Tran, Lauren Christine

    The Extraordinary Electroconductance (EEC) sensor has been previously demonstrated to have an electric field sensitivity of 3.05V/cm in a mesoscopic-scale structure fabricated at the center of a parallel plate capacitor. In this thesis, we demonstrate the first successful application of EEC sensors as electrochemical detectors of protein binding and biological molecule concentration. Using the avidin derivative, captavidin, in complex with the vitamin biotin, the change in four-point measured resistance with fluid protein concentration of bare EEC sensors was shown to increase by a factor of four in the presence of biomolecular binding as compared to baseline. Calculations for approximate field strengths introduced by a bound captavidin molecule are also presented. The development of Inverse-Extraordinary Optoconductance (I-EOC), an effect which occurs in nanoscale sensors, is also discussed. In the I-EOC effect, electron transport transitions from ballistic to diffusive with increasing light intensity. In these novel, room temperature optical detectors, the resistance is low at low light intensity and resistance increases by 9462% in a 250nm device mesa upon full illumination with a 5 mW HeNe laser. This is the inverse of bulk and mesoscopic device behavior, in which resistance decreases with increasing photon density.

  18. Extraordinary mode absorption at the electron cyclotron harmonic frequencies as a Tokamak plasma diagnostic

    International Nuclear Information System (INIS)

    Pachtman, A.

    1986-09-01

    Measurements of Extraordinary mode absorption at the electron cyclotron harmonic frequencies are of unique value in high temperature, high density Tokamak plasma diagnostic applications. An experimental study of Extraordinary mode absorption at the semi-opaque second and third harmonics has been performed on the ALCATOR C Tokamak. A narrow beam of submillimeter laser radiation was used to illuminate the plasma in a horizontal plane, providing a continuous measurement of the one-pass, quasi-perpendicular transmission

  19. Fiber-optic transmission system information for the testing of active phased antenna arrays in an anechoic chamber.

    Science.gov (United States)

    Saveleiv, I. K.; Sharova, N. V.; Tarasenko, M. Yu; Yalunina, T. R.; Davydov, V. V.; Rud', V. Yu

    2017-11-01

    The results of the research of the developed fiber-optic transmission systems for analog high frequency signal are represented. On its basis, a new method to identify various structural defects in the active phased antenna arrays is elaborated.

  20. Layered ACO-OFDM for intensity-modulated direct-detection optical wireless transmission.

    Science.gov (United States)

    Wang, Qi; Qian, Chen; Guo, Xuhan; Wang, Zhaocheng; Cunningham, David G; White, Ian H

    2015-05-04

    Layered asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) with high spectral efficiency is proposed in this paper for optical wireless transmission employing intensity modulation with direct detection. In contrast to the conventional ACO-OFDM, which only utilizes odd subcarriers for modulation, leading to an obvious spectral efficiency loss, in layered ACO-OFDM, the subcarriers are divided into different layers and modulated by different kinds of ACO-OFDM, which are combined for simultaneous transmission. In this way, more subcarriers are used for data transmission and the spectral efficiency is improved. An iterative receiver is also proposed for layered ACO-OFDM, where the negative clipping distortion of each layer is subtracted once it is detected so that the signals from different layers can be recovered. Theoretical analysis shows that the proposed scheme can improve the spectral efficiency by up to 2 times compared with conventional ACO-OFDM approaches with the same modulation order. Meanwhile, simulation results confirm a considerable signal-to-noise ratio gain over ACO-OFDM at the same spectral efficiency.

  1. The effect of scattering on single photon transmission of optical angular momentum

    International Nuclear Information System (INIS)

    Andrews, D L

    2011-01-01

    Schemes for the communication and registration of optical angular momentum depend on the fidelity of transmission between optical system components. It is known that electron spin can be faithfully relayed between exciton states in quantum dots; it has also been shown by several theoretical and experimental studies that the use of beams conveying orbital angular momentum can significantly extend the density and efficiency of such information transfer. However, it remains unclear to what extent the operation of such a concept at the single photon level is practicable—especially where this involves optical propagation through a material system, in which forward scattering events can intervene. The possibility of transmitting and decoding angular momentum over nanoscale distances itself raises other important issues associated with near-field interrogation. This paper provides a framework to address these and related issues. A quantum electrodynamical representation is constructed and used to pursue the consequences of individual photons, from a Laguerre–Gaussian beam, undergoing single and multiple scattering events in the course of propagation. In this context, issues concerning orbital angular momentum conservation, and its possible compromise, are tackled by identifying the relevant components of the electromagnetic scattering and coupling tensors, using an irreducible Cartesian basis. The physical interpretation broadly supports the fidelity of quantum information transmission, but it also identifies potential limitations of principle

  2. The effect of scattering on single photon transmission of optical angular momentum

    Science.gov (United States)

    Andrews, D. L.

    2011-06-01

    Schemes for the communication and registration of optical angular momentum depend on the fidelity of transmission between optical system components. It is known that electron spin can be faithfully relayed between exciton states in quantum dots; it has also been shown by several theoretical and experimental studies that the use of beams conveying orbital angular momentum can significantly extend the density and efficiency of such information transfer. However, it remains unclear to what extent the operation of such a concept at the single photon level is practicable—especially where this involves optical propagation through a material system, in which forward scattering events can intervene. The possibility of transmitting and decoding angular momentum over nanoscale distances itself raises other important issues associated with near-field interrogation. This paper provides a framework to address these and related issues. A quantum electrodynamical representation is constructed and used to pursue the consequences of individual photons, from a Laguerre-Gaussian beam, undergoing single and multiple scattering events in the course of propagation. In this context, issues concerning orbital angular momentum conservation, and its possible compromise, are tackled by identifying the relevant components of the electromagnetic scattering and coupling tensors, using an irreducible Cartesian basis. The physical interpretation broadly supports the fidelity of quantum information transmission, but it also identifies potential limitations of principle.

  3. Potential of optical spectral transmission measurements for joint inflammation measurements in rheumatoid arthritis patients

    Science.gov (United States)

    Meier, A. J. Louise; Rensen, Wouter H. J.; de Bokx, Pieter K.; de Nijs, Ron N. J.

    2012-08-01

    Frequent monitoring of rheumatoid arthritis (RA) patients enables timely treatment adjustments and improved outcomes. Currently this is not feasible due to a shortage of rheumatologists. An optical spectral transmission device is presented for objective assessment of joint inflammation in RA patients, while improving diagnostic accuracy and clinical workflow. A cross-sectional, nonrandomized observational study was performed with this device. In the study, 77 proximal interphalangeal (PIP) joints in 67 patients have been analyzed. Inflammation of these PIP joints was also assessed by a rheumatologist with a score varying from 1 (not inflamed) to 5 (severely inflamed). Out of 77 measurements, 27 were performed in moderate to strongly inflamed PIP joints. Comparison between the clinical assessment and an optical measurement showed a correlation coefficient r=0.63, p<0.001, 95% CI [0.47, 0.75], and a ROC curve (AUC=0.88) that shows a relative good specificity and sensitivity. Optical spectral transmission measurements in a single joint correlate with clinical assessment of joint inflammation, and therefore might be useful in monitoring joint inflammation in RA patients.

  4. Fifty years old, and still going strong: Transmission electron optical studies of materials

    International Nuclear Information System (INIS)

    Brown, L.M.

    2008-01-01

    Highlights in the history of transmission electron microscopy and scanning transmission electron microscopy include the introduction of diffraction contrast, resolution of periodic lattices by phase contrast and incoherent imaging via the high-angle annular dark-field detector. Convergent-beam electron diffraction and analytical electron microscopy, especially the application of energy-dispersive X-ray and electron energy-loss spectrometry, have provided structural and chemical information in addition to strain contrast from lattice defects. From the outset, novel specimen stages and improvements to aid the operator enhanced the electron-optical engineering provided by the instrument makers. The spatial resolution achieved was mainly determined by the way the instrument was used, and not by the basic resolution limit set by the electron optics. However, the application of computer controlled correction of spherical (and higher order) aberration has resulted in a new generation of instruments capable of sub-Angstrom point-to-point resolution. This improved performance, combined with electron energy-loss spectrometry, promises genuine three-dimensional determination of atomic and electronic structure: an indispensable weapon in the battle to fabricate and control useful nanostructures. The uncertainty principle now fundamentally restricts some of the observations one can make, but much more technical development over the next decades must occur before one can say that the techniques of electron-optical imaging of material structure have reached their fundamental limitations. One can expect remarkable progress over the next few years

  5. A ground-based optical transmission spectrum of WASP-6b

    International Nuclear Information System (INIS)

    Jordán, Andrés; Espinoza, Néstor; Rabus, Markus; Eyheramendy, Susana; Sing, David K.; Désert, Jean-Michel; Bakos, Gáspár Á.; Fortney, Jonathan J.; López-Morales, Mercedes; Szentgyorgyi, Andrew; Maxted, Pierre F. L.; Triaud, Amaury H. M. J.

    2013-01-01

    We present a ground-based optical transmission spectrum of the inflated sub-Jupiter-mass planet WASP-6b. The spectrum was measured in 20 spectral channels from 480 nm to 860 nm using a series of 91 spectra over a complete transit event. The observations were carried out using multi-object differential spectrophotometry with the Inamori-Magellan Areal Camera and Spectrograph on the Baade Telescope at Las Campanas Observatory. We model systematic effects on the observed light curves using principal component analysis on the comparison stars and allow for the presence of short and long memory correlation structure in our Monte Carlo Markov Chain analysis of the transit light curves for WASP-6. The measured transmission spectrum presents a general trend of decreasing apparent planetary size with wavelength and lacks evidence for broad spectral features of Na and K predicted by clear atmosphere models. The spectrum is consistent with that expected for scattering that is more efficient in the blue, as could be caused by hazes or condensates in the atmosphere of WASP-6b. WASP-6b therefore appears to be yet another massive exoplanet with evidence for a mostly featureless transmission spectrum, underscoring the importance that hazes and condensates can have in determining the transmission spectra of exoplanets.

  6. Two-step frequency conversion for connecting distant quantum memories by transmission through an optical fiber

    Science.gov (United States)

    Tamura, Shuhei; Ikeda, Kohei; Okamura, Kotaro; Yoshii, Kazumichi; Hong, Feng-Lei; Horikiri, Tomoyuki; Kosaka, Hideo

    2018-06-01

    Long-distance quantum communication requires entanglement between distant quantum memories. For this purpose, photon transmission is necessary to connect the distant memories. Here, for the first time, we develop a two-step frequency conversion process (from a visible wavelength to a telecommunication wavelength and back) involving the use of independent two-frequency conversion media where the target quantum memories are nitrogen-vacancy centers in diamonds (with an emission/absorption wavelength of 637.2 nm), and experimentally characterize the performance of this process acting on light from an attenuated CW laser. A total conversion efficiency of approximately 7% is achieved. The noise generated in the frequency conversion processes is measured, and the signal-to-noise ratio is estimated for a single photon signal emitted by a nitrogen-vacancy (NV) center. The developed frequency conversion system has future applications via transmission through a long optical fiber channel at a telecommunication wavelength for a quantum repeater network.

  7. A new optical transmission spectrum of WASP-43b from ACCESS

    Science.gov (United States)

    Weaver, Ian; University of Arizona, Católica, Carnegie

    2018-01-01

    We present a new ground-based optical transmission spectrum of the Hot Jupiter WASP--43b obtained with the Inamori-Magellan Areal Camera and Spectrograph (IMACS) on the Baade Telescope at Las Campanas Observatory. These observations were made as part of the Arizona-CfA-Catolica+Carnegie Exoplanet Spectroscopy Survey (ACCESS), which aims at providing a uniform, large sample of visible transmission spectra of gaseous exoplanets that will become key in the era of JWST and comparative exoplanetology. Using multi-object differential spectrophotometry, we produce a high precision spectrum of this planet between 400 and 900 nm, combining three different transit epochs. In this analysis, we search for signals of Na I, H-alpha, and K I, as well as for the presence of hazes/clouds.

  8. Comparison of single-/few-/multi-mode 850 nm VCSELs for optical OFDM transmission.

    Science.gov (United States)

    Kao, Hsuan-Yun; Tsai, Cheng-Ting; Leong, Shan-Fong; Peng, Chun-Yen; Chi, Yu-Chieh; Huang, Jian Jang; Kuo, Hao-Chung; Shih, Tien-Tsorng; Jou, Jau-Ji; Cheng, Wood-Hi; Wu, Chao-Hsin; Lin, Gong-Ru

    2017-07-10

    For high-speed optical OFDM transmission applications, a comprehensive comparison of the homemade multi-/few-/single-transverse mode (MM/FM/SM) vertical cavity surface emitting laser (VCSEL) chips is performed. With microwave probe, the direct encoding of pre-leveled 16-QAM OFDM data and transmission over 100-m-long OM4 multi-mode-fiber (MMF) are demonstrated for intra-datacenter applications. The MM VCSEL chip with the largest emission aperture of 11 μm reveals the highest differential quantum efficiency which provides the highest optical power of 8.67 mW but exhibits the lowest encodable bandwidth of 21 GHz. In contrast, the SM VCSEL chip fabricated with the smallest emission aperture of only 3 μm provides the highest 3-dB encoding bandwidth up to 23 GHz at a cost of slight heat accumulation. After optimization, with the trade-off set between the receiving signal-to-noise ratio (SNR) and bandwidth, the FM VCSEL chip guarantees the highest optical OFDM transmission bit rate of 96 Gbit/s under back-to-back case with its strongest throughput. Among three VCSEL chips, the SM VCSEL chip with nearly modal-dispersion free feature is treated as the best candidate for carrying the pre-leveled 16-QAM OFDM data over 100-m OM4-MMF with same material structure but exhibits different oxide-layer confined gain cross-sections with one another at 80-Gbit/s with the smallest receiving power penalty of 1.77 dB.

  9. 4.7 Gbit/s transmission over 50m long 1mm diameter multi-core plastic optical fiber

    NARCIS (Netherlands)

    Yang, H.; Tangdiongga, E.; Lee, S.C.J.; Okonkwo, C.M.; Boom, van den H.P.A.; Randel, S.; Koonen, A.M.J.

    2010-01-01

    We report, for the first time, 4.7 Gbit/s transmission over 50 m long 1 mm diameter multi-core step-index plastic optical fiber, employing discrete multitone techniques and low-cost optical transceiver. A spectral efficiency of 13 bit/s/Hz is demonstrated.

  10. Optical LDPC decoders for beyond 100 Gbits/s optical transmission.

    Science.gov (United States)

    Djordjevic, Ivan B; Xu, Lei; Wang, Ting

    2009-05-01

    We present an optical low-density parity-check (LDPC) decoder suitable for implementation above 100 Gbits/s, which provides large coding gains when based on large-girth LDPC codes. We show that a basic building block, the probabilities multiplier circuit, can be implemented using a Mach-Zehnder interferometer, and we propose corresponding probabilistic-domain sum-product algorithm (SPA). We perform simulations of a fully parallel implementation employing girth-10 LDPC codes and proposed SPA. The girth-10 LDPC(24015,19212) code of the rate of 0.8 outperforms the BCH(128,113)xBCH(256,239) turbo-product code of the rate of 0.82 by 0.91 dB (for binary phase-shift keying at 100 Gbits/s and a bit error rate of 10(-9)), and provides a net effective coding gain of 10.09 dB.

  11. Analog signals transmission of up to 100 khz though optical fiber

    International Nuclear Information System (INIS)

    Cremy, C.

    1996-12-01

    Around TJ-II device, potential problems may arise as a consequence of an adverse electromagnetic environment, presence of strong DC and AC currents, motors, coils, power supplies, magnetic fields and so on. Consequently, signal transmission towards monitoring or data acquisition systems may be affected due to induced noise, ground loops and other undesirable effects. Trying to avoid such problems, signals may be translated in a proper way in order to be routed through optical fiber. The present report shows a method to solve the difficulty, by means of a galvanic isolation between the signal source and the measurement circuit. (Author)

  12. Optical transmission control in graphene oxide and its organic composites with ultrashort laser pulses

    International Nuclear Information System (INIS)

    Bala Murali Krishna, M; Narayana Rao, D; Venkatramaiah, N

    2014-01-01

    Nonlinear optical transmission of graphene oxide–(Cu, Zn, Sn, H 2 ) porphyrin composites was investigated using the Z-scan technique at 532 nm with picosecond (ps) and 800 nm with femtosecond laser pulses. Pure porphyrins show saturable absorption (SA) in reverse saturable absorption (RSA) behaviour and graphene oxide shows complete RSA behaviour, observed in an open aperture Z-scan curve. Interestingly, composites have shown a switch-over from reverse RSA to SA and back to RSA behaviour, observed with variation of intensity towards the focus, due to strong two-photon absorption as well as excited state absorption in the ps regime. This switching behaviour was interpreted as due to long lifetimes and saturation of the excited states. This may find application in optical switching. (paper)

  13. Experimental study of non-binary LDPC coding for long-haul coherent optical QPSK transmissions.

    Science.gov (United States)

    Zhang, Shaoliang; Arabaci, Murat; Yaman, Fatih; Djordjevic, Ivan B; Xu, Lei; Wang, Ting; Inada, Yoshihisa; Ogata, Takaaki; Aoki, Yasuhiro

    2011-09-26

    The performance of rate-0.8 4-ary LDPC code has been studied in a 50 GHz-spaced 40 Gb/s DWDM system with PDM-QPSK modulation. The net effective coding gain of 10 dB is obtained at BER of 10(-6). With the aid of time-interleaving polarization multiplexing and MAP detection, 10,560 km transmission over legacy dispersion managed fiber is achieved without any countable errors. The proposed nonbinary quasi-cyclic LDPC code achieves an uncoded BER threshold at 4×10(-2). Potential issues like phase ambiguity and coding length are also discussed when implementing LDPC in current coherent optical systems. © 2011 Optical Society of America

  14. Development of a visible light transmission (VLT) measurement system using an open-path optical method

    Science.gov (United States)

    Nurulain, S.; Manap, H.

    2017-09-01

    This paper describes about a visible light transmission (VLT) measurement system using an optical method. VLT rate plays an important role in order to determine the visibility of a medium. Current instrument to measure visibility has a gigantic set up, costly and mostly fails to function at low light condition environment. This research focuses on the development of a VLT measurement system using a simple experimental set-up and at a low cost. An open path optical technique is used to measure a few series of known-VLT thin film that act as sample of different visibilities. This measurement system is able to measure the light intensity of these thin films within the visible light region (535-540 nm) and the response time is less than 1s.

  15. Optical transmission and laser ablation of pathologically changed eye lens capsule

    Energy Technology Data Exchange (ETDEWEB)

    Gamidov, A A; Bolshunov, A V [Research Institute of Eye Diseases, Russian Academy of Medical Sciences, Moscow (Russian Federation); Yuzhakov, A V; Shcherbakov, E M; Baum, O I; Sobol, E N [Institute on Laser and Information Technologies, Russian Academy of Sciences, Shatura, Moscow Region (Russian Federation)

    2015-02-28

    Optical transmission and ablation mechanisms in the secondary cataract films under the impact of 1.06-mm laser radiation are studied. The comparison of incident and transmitted (paraxial) radiation power at different values of the power density is carried out for two types of the eye lens capsule tissue (hard and soft) possessing different optical and mechanical properties. It is found that the effective attenuation coefficient for soft films is almost five times as large as that for the hard ones. The obtained measurement data on the transparency variation in the process of laser action allow the temperature evaluation and the determination of dominant mechanism of laser ablation, as well as the development of recommendations, providing the prevention or reduction of possible side effects. The obtained results can be used to optimise the regimes of laser impact in the process of the opacified lens capsule removal.

  16. Data transmission with twisted light through a free-space to fiber optical communication link

    International Nuclear Information System (INIS)

    Brüning, Robert; Duparré, Michael; Ndagano, Bienvenu; McLaren, Melanie; Forbes, Andrew; Schröter, Siegmund; Kobelke, Jens

    2016-01-01

    Mode division multiplexing (MDM), where information is transmitted in the spatial modes of light, is mooted as a future technology with which to transmit large bits of information. However, one of the key issues in optical communication lies in connecting free-space to optical fiber networks, otherwise known as the ‘last mile’ problem. This is particularly problematic for MDM as the eigenmodes of free-space and fibers are in general not the same. Here we demonstrate a data transmission scheme across a free-space and fiber link using twisted light in the form of Laguerre–Gaussian (LG) azimuthal modes. As a proof-of-principle we design and implement a custom fiber where the supported LG modes can be grouped into five non-degenerate sets, and successfully transmit a gray-scale image across the composite link using one mode from each group, thereby ensuring minimal crosstalk. (letter)

  17. Manipulating Acoustic Wavefront by Inhomogeneous Impedance and Steerable Extraordinary Reflection

    Science.gov (United States)

    Zhao, Jiajun; Li, Baowen; Chen, Zhining; Qiu, Cheng-Wei

    2013-08-01

    We unveil the connection between the acoustic impedance along a flat surface and the reflected acoustic wavefront, in order to empower a wide wariety of novel applications in acoustic community. Our designed flat surface can generate double reflections: the ordinary reflection and the extraordinary one whose wavefront is manipulated by the proposed impedance-governed generalized Snell's law of reflection (IGSL). IGSL is based on Green's function and integral equation, instead of Fermat's principle for optical wavefront manipulation. Remarkably, via the adjustment of the designed specific acoustic impedance, extraordinary reflection can be steered for unprecedented acoustic wavefront while that ordinary reflection can be surprisingly switched on or off. The realization of the complex discontinuity of the impedance surface has been proposed using Helmholtz resonators.

  18. Radiation-hard ASICS for sLHC optical data transmission

    International Nuclear Information System (INIS)

    Gan, K.K.

    2009-01-01

    High-speed data transmission in a high radiation environment poses an immense challenge in the detector design. We investigate the feasibility of using optical links for the silicon trackers of the ATLAS experiment for the planned upgrade of the LHC. The planned upgrade with ten times higher collision rate will produce a similar increase in the radiation. One possibility for the optical transmission is to use VCSEL arrays operating at 850 nm to transmit optical signals while using PIN arrays to convert the optical signals into electrical signals. We have designed a prototype chip containing building blocks for future SLHC optical links using a 130 nm CMOS 8RF process. The chip contains four main blocks; a VCSEL driver optimized for operation at 640 Mb/s, a VCSEL driver optimized for 3.2 Gb/s, a PIN receiver with a clock/data recovery circuit for operation at 40, 160, and 320 Mb/s, and two clock multipliers designed to operate at 640 Mb/s. The clock multiplier is designed to produce the high speed clock to serialize the data for transmission. All circuitry was designed following test results and guidelines from CERN on radiation tolerant design for the process. We have irradiated the chips with 24 GeV protons at CERN. For the VDC, the duty cycle of the output signal and the current consumption of the LVDS receiver remained constant during the irradiation. However, we observed significant decreases in the current consumption of the VCSEL driver circuit and the output drive current. This indicated that the think oxide layout used in the VCSEL driver portion of the chip might not be as radiation-hard and the circuit had been redesigned to minimize this sensitivity. For the PIN receiver, we found that the radiation produced no significant degradation, including the single event upset rate. The upset rate decreased with larger PIN current and was higher for a chip coupled to a PIN diode as expected. For the clock multipliers, we observed that the clocks of some chips

  19. Design of an optical temporal integrator based on a phase-shifted fiber Bragg grating in transmission.

    Science.gov (United States)

    Quoc Ngo, Nam

    2007-10-15

    We present a theoretical study of a new application of a simple pi-phase-shifted fiber Bragg grating (PSFBG) in transmission mode as a high-speed optical temporal integrator. The PSFBG consists of two concatenated identical uniform FBGs with a pi phase shift between them. When the reflectivities of the FBGs are extremely close to 100%, the transmissive PSFBG can perform the time integral of the complex envelope of an arbitrary input optical signal with high accuracy. As an example, the integrator is numerically shown to be able to convert an input Gaussian pulse into an optical step signal.

  20. FURTHER CONSTRAINTS ON THE OPTICAL TRANSMISSION SPECTRUM OF HAT-P-1b

    International Nuclear Information System (INIS)

    Montalto, M.; Santos, N. C.; Martins, J. H. C.; Figueira, P.; Alonso, R.; Iro, N.; Desidera, S.

    2015-01-01

    We report on novel observations of HAT-P-1 aimed at constraining the optical transmission spectrum of the atmosphere of its transiting hot-Jupiter exoplanet. Ground-based differential spectrophotometry was performed over two transit windows using the DOLORES spectrograph at the Telescopio Nazionale Galileo. Our measurements imply an average planet to star radius ratio equal to R p /R * = (0.1159 ± 0.0005). This result is consistent with the value obtained from recent near-infrared measurements of this object, but differs from previously reported optical measurements, being lower by around 4.4 exoplanet scale heights. Analyzing the data over five different spectral bins of ∼600 Å wide, we observed a single peaked spectrum (3.7 σ level) with a blue cutoff corresponding to the blue edge of the broad absorption wing of sodium and an increased absorption in the region in-between 6180 and 7400 Å. We also infer that the width of the broad absorption wings due to alkali metals is likely narrower than the one implied by solar abundance clear atmospheric models. We interpret the result as evidence that HAT-P-1b has a partially clear atmosphere at optical wavelengths with a more modest contribution from an optical absorber than previously reported

  1. FURTHER CONSTRAINTS ON THE OPTICAL TRANSMISSION SPECTRUM OF HAT-P-1b

    Energy Technology Data Exchange (ETDEWEB)

    Montalto, M.; Santos, N. C.; Martins, J. H. C.; Figueira, P.; Alonso, R. [Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto (Portugal); Iro, N. [Theoretical Meteorology Group Klimacampus, University of Hamburg Grindelberg 5, D-20144, Hamburg (Germany); Desidera, S., E-mail: Marco.Montalto@astro.up.pt [INAF—Osservatorio Astronomico di Padova, Vicolo dellOsservatorio 5, Padova, I-35122 (Italy)

    2015-09-20

    We report on novel observations of HAT-P-1 aimed at constraining the optical transmission spectrum of the atmosphere of its transiting hot-Jupiter exoplanet. Ground-based differential spectrophotometry was performed over two transit windows using the DOLORES spectrograph at the Telescopio Nazionale Galileo. Our measurements imply an average planet to star radius ratio equal to R{sub p}/R{sub *} = (0.1159 ± 0.0005). This result is consistent with the value obtained from recent near-infrared measurements of this object, but differs from previously reported optical measurements, being lower by around 4.4 exoplanet scale heights. Analyzing the data over five different spectral bins of ∼600 Å wide, we observed a single peaked spectrum (3.7 σ level) with a blue cutoff corresponding to the blue edge of the broad absorption wing of sodium and an increased absorption in the region in-between 6180 and 7400 Å. We also infer that the width of the broad absorption wings due to alkali metals is likely narrower than the one implied by solar abundance clear atmospheric models. We interpret the result as evidence that HAT-P-1b has a partially clear atmosphere at optical wavelengths with a more modest contribution from an optical absorber than previously reported.

  2. Optical and Optoelectronic Property Analysis of Nanomaterials inside Transmission Electron Microscope.

    Science.gov (United States)

    Fernando, Joseph F S; Zhang, Chao; Firestein, Konstantin L; Golberg, Dmitri

    2017-12-01

    In situ transmission electron microscopy (TEM) allows one to investigate nanostructures at high spatial resolution in response to external stimuli, such as heat, electrical current, mechanical force and light. This review exclusively focuses on the optical, optoelectronic and photocatalytic studies inside TEM. With the development of TEMs and specialized TEM holders that include in situ illumination and light collection optics, it is possible to perform optical spectroscopies and diverse optoelectronic experiments inside TEM with simultaneous high resolution imaging of nanostructures. Optical TEM holders combining the capability of a scanning tunneling microscopy probe have enabled nanomaterial bending/stretching and electrical measurements in tandem with illumination. Hence, deep insights into the optoelectronic property versus true structure and its dynamics could be established at the nanometer-range precision thus evaluating the suitability of a nanostructure for advanced light driven technologies. This report highlights systems for in situ illumination of TEM samples and recent research work based on the relevant methods, including nanomaterial cathodoluminescence, photoluminescence, photocatalysis, photodeposition, photoconductivity and piezophototronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. High speed optical wireless data transmission system for particle sensors in high energy physics

    Science.gov (United States)

    Ali, W.; Corsini, R.; Ciaramella, E.; Dell'Orso, R.; Messineo, A.; Palla, F.

    2015-08-01

    High speed optical fiber or copper wire communication systems are frequently deployed for readout data links used in particle physics detectors. Future detector upgrades will need more bandwidth for data transfer, but routing requirements for new cables or optical fiber will be challenging due to space limitations. Optical wireless communication (OWC) can provide high bandwidth connectivity with an advantage of reduced material budget and complexity of cable installation and management. In a collaborative effort, Scuola Superiore Sant'Anna and INFN Pisa are pursuing the development of a free-space optical link that could be installed in a future particle physics detector or upgrade. We describe initial studies of an OWC link using the inner tracker of the Compact Muon Solenoid (CMS) detector as a reference architecture. The results of two experiments are described: the first to verify that the laser source transmission wavelength of 1550 nm will not introduce fake signals in silicon strip sensors while the second was to study the source beam diameter and its tolerance to misalignment. For data rates of 2.5 Gb/s and 10 Gb/s over a 10 cm working distance it was observed that a tolerance limit of ±0.25 mm to ±0.8 mm can be obtained for misaligned systems with source beam diameters of 0.38 mm to 3.5 mm, respectively.

  4. Impairment mitigation in noncoherent optical transmission enabled with machine learning for intra-datacenter networks

    Science.gov (United States)

    Ito, Keisuke; Niwa, Masaki; Ueda, Koh; Mori, Yojiro; Hasegawa, Hiroshi; Sato, Ken-ichi

    2017-01-01

    Ever-increasing intra-datacenter traffic will spur the introduction of high-baud rates and high-order modulation formats. Increasing symbol rates and modulation levels decreases tolerance against transmission impairment that includes chromatic dispersion. Transmission distance in warehouse-scale datacenters can be several kilometers, and then management of chromatic dispersion is necessary. Dispersion-compensating fibers are widely deployed in backbone networks, however, applying them in datacenters is not cost-effective since wavelength channels are coarsely multiplexed. In digital coherent systems, signal distortion due to chromatic dispersion can be resolved in digital domain; however, it will take long time before coherent systems can be introduced in datacenter networks because of their high cost. In this paper, we propose a novel impairment mitigation method employing machine learning. The proposed method is effective even after non-coherent detection and hence it can be applied to cost-sensitive intra-datacenter networks. The machine learns optimum symbol-decision criteria from a sequence of dispersed training signals, and it discriminates payload signals in accordance with the established decision criteria. With the scheme, the received signals can be demodulated in the presence of large chromatic dispersion. The transmission distance thus can be extended without relying on costly optical dispersion compensation. Since information of transmission links is not a priori required, the proposed scheme can easily be applied to any datacenter network. We conduct transmission experiments using 400-Gbps channels each of which comprises 8-subcarrier 28-Gbaud 4-ary pulse-amplitude-modulation (PAM-4) signals, and confirm the effectiveness of the proposed scheme.

  5. Analysis of optical transmission by 400-500 nm visible light into aesthetic dental biomaterials.

    Science.gov (United States)

    Watts, D C; Cash, A J

    1994-04-01

    The penetration of visible light into dental biomaterials is an essential factor in photoinitiation of setting reactions and in the optical aspects of dental aesthetics. Light of visible blue wavelengths, 400-500 nm, has been applied at normal angles to 0.2-5.0 mm sections of human dentine and representative ceramic, polymerceramic composites and hybrid glass-polyalkenoate materials. The integrated optical transmission has been determined for each material section. The data have been converted to absorbance values and analysed to check for mathematical conformity to the Beer-Lambert Law. It is found that conformity (typically, P ratio. This factor ranges from 30% to 90% in the materials investigated. It follows that there is a high degree of inefficiency in the transmission of visible light into and through aesthetic biomaterials for the purposes of photoactivation using existing technology. Means by which this limitation and inefficiency may be reduced are discussed. While the reflectivity of aesthetic biomaterials has been perceived by dental practitioners, the magnitude of this effect and its implications in connection with light-cured materials have not been analysed and emphasized hitherto.

  6. Secure Communications in High Speed Fiber Optical Networks Using Code Division Multiple Access (CDMA) Transmission

    Energy Technology Data Exchange (ETDEWEB)

    Han, I; Bond, S; Welty, R; Du, Y; Yoo, S; Reinhardt, C; Behymer, E; Sperry, V; Kobayashi, N

    2004-02-12

    This project is focused on the development of advanced components and system technologies for secure data transmission on high-speed fiber optic data systems. This work capitalizes on (1) a strong relationship with outstanding faculty at the University of California-Davis who are experts in high speed fiber-optic networks, (2) the realization that code division multiple access (CDMA) is emerging as a bandwidth enhancing technique for fiber optic networks, (3) the realization that CDMA of sufficient complexity forms the basis for almost unbreakable one-time key transmissions, (4) our concepts for superior components for implementing CDMA, (5) our expertise in semiconductor device processing and (6) our Center for Nano and Microtechnology, which is where the majority of the experimental work was done. Here we present a novel device concept, which will push the limits of current technology, and will simultaneously solve system implementation issues by investigating new state-of-the-art fiber technologies. This will enable the development of secure communication systems for the transmission and reception of messages on deployed commercial fiber optic networks, through the CDMA phase encoding of broad bandwidth pulses. CDMA technology has been developed as a multiplexing technology, much like wavelength division multiplexing (WDM) or time division multiplexing (TDM), to increase the potential number of users on a given communication link. A novel application of the techniques created for CDMA is to generate secure communication through physical layer encoding. Physical layer encoding devices are developed which utilize semiconductor waveguides with fast carrier response times to phase encode spectral components of a secure signal. Current commercial technology, most commonly a spatial light modulator, allows phase codes to be changed at rates of only 10's of Hertz ({approx}25ms response). The use of fast (picosecond to nanosecond) carrier dynamics of semiconductors

  7. Golay sequences coded coherent optical OFDM for long-haul transmission

    Science.gov (United States)

    Qin, Cui; Ma, Xiangrong; Hua, Tao; Zhao, Jing; Yu, Huilong; Zhang, Jian

    2017-09-01

    We propose to use binary Golay sequences in coherent optical orthogonal frequency division multiplexing (CO-OFDM) to improve the long-haul transmission performance. The Golay sequences are generated by binary Reed-Muller codes, which have low peak-to-average power ratio and certain error correction capability. A low-complexity decoding algorithm for the Golay sequences is then proposed to recover the signal. Under same spectral efficiency, the QPSK modulated OFDM with binary Golay sequences coding with and without discrete Fourier transform (DFT) spreading (DFTS-QPSK-GOFDM and QPSK-GOFDM) are compared with the normal BPSK modulated OFDM with and without DFT spreading (DFTS-BPSK-OFDM and BPSK-OFDM) after long-haul transmission. At a 7% forward error correction code threshold (Q2 factor of 8.5 dB), it is shown that DFTS-QPSK-GOFDM outperforms DFTS-BPSK-OFDM by extending the transmission distance by 29% and 18%, in non-dispersion managed and dispersion managed links, respectively.

  8. Study of lineal and non-lineal transmission of an optical fiber Sagnac interferometer as a bidirectional device

    International Nuclear Information System (INIS)

    Ramos-Beltran, J; Beltran-Perez, G; Castillo-Mixcoatl, J; Munoz-Aguirre, S; Zaca-Moran, P; Felipe, C

    2011-01-01

    The optical fiber Sagnac interferometer is a versatile system that has been investigated for a variety of applications such as optical switchers, filters, demultiplexers and passive mode-locked laser. In many cases, this arrangement is designed using a symmetrical coupler with two of their ports connected making a loop and generally the analysis have been focused in the transmission of the signal propagated in only one direction. Therefore in the present work a complementary study of the system considering the analysis for the lineal and non-lineal transmission as a bidirectional device has been performed. The experimental setup consists of different optical fiber lengths inside the cavity loop (between 100 and 500 m) with highly twisted singlemode fiber, a quarter wave retarder placed asymmetrically in one arm and a 50/50 coupler. The results have shown that for low optical powers, it is possible to adjust the system transmission in both propagation directions with the rotation of the retarder wave. On the other hand, in high optical power levels, this arrangement showed that the transmission increases slowly for the case when both the input and the output beams have the same polarization. This behavior can be used for pedestal suppression in a light pulse. Furthermore, for the case when the output signal polarization is orthogonal respect to the input one, the transmission changes quite fast. This effect can be used for applications such as the passive mode-locking.

  9. Yelavarthy Nayudamma: Scientist, Leader, and Mentor Extraordinary

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 10. Yelavarthy Nayudamma: Scientist, Leader, and Mentor Extraordinary. J Raghava Rao T Ramasami. General Article Volume 19 Issue 10 October 2014 pp 887-899 ...

  10. Optical fiber sources and transmission controls for multi-Tb/s systems

    Science.gov (United States)

    Nowak, George Adelbert

    The accelerating demand for bandwidth capacity in backbone links of terrestrial communications systems is projected to exceed 1Tb/s by 2002. Lightwave carrier frequencies and fused-silica optical fibers provide the natural combination of high passband frequencies and low- loss medium to satisfy this evolving demand for bandwidth capacity. This thesis addresses three key technologies for enabling multi-Tb/s optical fiber communication systems. The first technology is a broadband source based on supercontinuum generation in optical fiber. Using a single modelocked laser with output pulsewidths of 0.5psec pulses, we generate in ~2m of dispersion-shifted fiber more that 200nm of spectral continuum in the vicinity of 1550nm that is flat to better than +/- 0.5 dB over more than 60nm. The short fiber length prevents degradation of timing jitter of the seed pulses and preserves coherence of the continuum by inhibiting environmental perturbations and mapping of random noise from the vicinity of the input pulse across the continuum. Through experiments and simulations, we find that the continuum characteristics result from 3rd order dispersion effects on higher-order soliton compression. We determine optimal fiber properties to provide desired continuum broadness and flatness for given input pulsewidth and energy conditions. The second technology is a novel delay-shifted nonlinear optical loop mirror (DS-NOLM) that performs a transmission control function by serving as an intensity filter and frequency compensator for 4ps soliton transmission over 75km of standard dispersion fiber, with 25km spacing between amplifiers, by filtering the dispersive waves and compensating for Raman-induced soliton self-frequency shift. The third technology is all-fiber wavelength conversion employing induced modulational instability. We obtain wavelength conversion over 40nm with a peak conversion efficiency of 28dB using 600mW pump pulses in 720m of high-nonlinearity optical fiber. We show

  11. Transmission Grating and Optics Technology Development for the Arcus Explorer Mission

    Science.gov (United States)

    Heilmann, Ralf; Arcus Team

    2018-01-01

    Arcus is a high-resolution x-ray spectroscopy MIDEX mission selected for a Phase A concept study. It is designed to explore structure formation through measurements of hot baryon distributions, feedback from black holes, and the formation and evolution of stars, disks, and exoplanet atmospheres. The design provides unprecedented sensitivity in the 1.2-5 nm wavelength band with effective area above 450 sqcm and spectral resolution R > 2500. The Arcus technology is based on 12 m-focal length silicon pore optics (SPO) developed for the European Athena mission, and critical-angle transmission (CAT) x-ray diffraction gratings and x-ray CCDs developed at MIT. The modular design consists of four parallel channels, each channel holding an optics petal, followed by a grating petal. CAT gratings are lightweight, alignment insensitive, high-efficiency x-ray transmission gratings that blaze into high diffraction orders, leading to high spectral resolution. Each optics petal represents an azimuthal sub-aperture of a full Wolter optic. The sub-aperturing effect increases spectral resolving power further. Two CCD readout strips receive photons from each channel, including higher-energy photons in 0th order. Each optics petal holds 34 SPO modules. Each grating petal holds 34 grating windows, and each window holds 4-6 grating facets. A grating facet consists of a silicon grating membrane, bonded to a flexure frame that interfaces with the grating window. We report on a sequence of tests with increasing complexity that systematically increase the Technology Readiness Level (TRL) for the combination of CAT gratings and SPOs towards TLR 6. CAT gratings have been evaluated in x rays for diffraction efficiency (> 30% at 2.5 nm) and for resolving power (R> 10,000). A CAT grating/SPO combination was measured at R ~ 3100 at blaze angles smaller than design values, exceeding Arcus requirements. Efficiency and resolving power were not impacted by vibration and thermal testing of gratings. A

  12. Biomimetic hairy surfaces as superhydrophobic highly transmissive films for optical applications (Conference Presentation)

    Science.gov (United States)

    Vuellers, Felix; Gomard, Guillaume; Preinfalk, Jan B.; Klampaftis, Efthymios; Worgull, Matthias; Richards, Bryce S.; Hölscher, Hendrik; Kavalenka, Maryna N.

    2017-02-01

    Combining high optical transmission, water-repellency and self-cleaning is of great interest for optoelectronic devices operating in outdoor conditions, such as photovoltaics where shading can significantly reduce the power output. The surface of water plant Pistia stratiotes combines these functionalities through a dense layer of transparent microhairs. It renders the surface superhydrophobic without affecting absorption of sunlight necessary for photosynthesis. Inspired by this surface, we fabricated a superhydrophobic flexible thin nanofur film made from optical grade polycarbonate using a scalable combination of hot embossing and hot pulling techniques. During fabrication, heated sandblasted steel plates locally elongate softened polymer, thus covering its surface in microcavities surrounded by high aspect ratio micro- and nanohairs. The superhydrophobic nanofur exhibits contact angles of (166+/-6°), low sliding angles (drops below 4% when coated on a polymeric substrate, which can enhance light extraction in organic light emitting diodes (OLEDs). We report an increase of more than 10% in luminous efficacy for a nanofur coated OLED compared to a bare device. Finally, the nanofur film can be used for enhancing the incoupling of light to solar cells, while additionally providing self-cleaning properties. Optical coupling of the nanofur to a multi-crystalline silicon solar cell results in a 5.8% gain in photocurrent compared to a bare device under normal incidence.

  13. Comb-like optical transmission spectrum resulting from a four-cornered two-waveguide-connected network

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiangbo, E-mail: xbyang@scnu.edu.cn [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631 (China); School of Physical Education and Sports Science, South China Normal University, Guangzhou 510006 (China); Song, Huanhuan [MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631 (China); Liu, Timon Chengyi [School of Physical Education and Sports Science, South China Normal University, Guangzhou 510006 (China)

    2013-12-06

    In this Letter a four-cornered two-waveguide-connected network (FCTWCN) is proposed to generate comb-like optical transmission spectrum, where nearest-neighbor nodes are connected by two segments of one-dimensional waveguides. We investigate the band structure and transmission spectrum of electromagnetic waves propagating through FCTWCNs and find that the transmission through a FCTWCN exhibits periodic comb-like characteristic and the range, number and width of continuous equidistant frequency bands can be controlled by adjusting the lengths of the two types of segments. The comb-like frequency bands may be useful for the designing of optical switches, optical narrowband filters, high capacity telecommunications, and multichannel filters, etc.

  14. Modulations of anisotropic optical transmission on alumina-doped zinc oxide surface by femtosecond laser induced ripples

    Science.gov (United States)

    Lu, Yanhui; Jiang, Lan; Sun, Jingya; Cao, Qiang; Wang, Qingsong; Han, Weina; Lu, Yongfeng

    2018-04-01

    This study demonstrated that femtosecond-laser-induced ripples on an alumina-doped zinc oxide (AZO) film with space intervals of approximately 340 and 660 nm exhibit modulations of anisotropic optical transmission. At low laser fluence, ripples can not affect the original absorption peak of AZO film, but at higher laser fluence, the absorption peak of AZO film is disappeared due to the modulation by femtosecond laser induced ripples. Moreover, the relationship between the anisotropic optical transmission and the features of nanostructures is discussed. Ripples with a space interval of approximately 660 nm have a higher ability to block light than nanostructures with a space interval of approximately 340 nm. These observations indicate that anisotropic optical transmission has potential applications in the field of optoelectronics.

  15. Performance Enhancement of Optical CDMA by Differential-Phase Method for Radio-over-Fiber Transmissions

    Directory of Open Access Journals (Sweden)

    Hsu-Chih Cheng

    2013-01-01

    Full Text Available The study proposes the differential-phase optical code-division multiple-access (OCDMA network for radio-over-fiber (RoF transmissions, and the characteristics are numerically analyzed. The network coder/decoders (codecs are structured on the basis of arrayed-waveguide-grating (AWG routers with complementary Walsh-Hadamard (CWH signature codes. In the proposed system, the network requires only two AWG routers to accomplish spectral encoding of radio base station (RBS and decoding of control station for the complementary keying, thus resulting in a simpler and low cost system. Performance analyses are evaluated with the dominant noise of phase-induced intensity noise (PIIN in spectral code OCDMA network. By the proposed AWG-based OCDMA with the differential-phase scheme, it is possible to establish interference-free and low crosstalk beat noise RoF systems.

  16. Optical data transmission ASICs for the high-luminosity LHC (HL-LHC) experiments

    International Nuclear Information System (INIS)

    Li, X; Huang, G; Sun, X; Liu, G; Deng, B; Gong, D; Guo, D; Liu, C; Liu, T; Xiang, A C; Ye, J; Zhao, X; Chen, J; You, Y; He, M; Hou, S; Teng, P-K; Jin, G; Liang, H; Liang, F

    2014-01-01

    We present the design and test results of two optical data transmission ASICs for the High-Luminosity LHC (HL-LHC) experiments. These ASICs include a two-channel serializer (LOCs2) and a single-channel Vertical Cavity Surface Emitting Laser (VCSEL) driver (LOCld1V2). Both ASICs are fabricated in a commercial 0.25-μm Silicon-on-Sapphire (SoS) CMOS technology and operate at a data rate up to 8 Gbps per channel. The power consumption of LOCs2 and LOCld1V2 are 1.25 W and 0.27 W at 8-Gbps data rate, respectively. LOCld1V2 has been verified meeting the radiation-tolerance requirements for HL-LHC experiments

  17. Mechanism of optical unidirectional transmission in subwavelength dual-metal gratings

    Science.gov (United States)

    Gao, H.; Zheng, Z. Y.; Hao, H. Y.; Dong, A. G.; Fan, Z. J.; Liu, D. H.

    2014-03-01

    The mechanism of optical unidirectional (OUD) transmission in parallel subwavelength dual-metal gratings was investigated. It was found that this kind of OUD phenomenon originates from the coupling of the surface plasmon polaritons (SPPs) between the front grating and a layer of metal film which replaces the rear grating. The higher the intensity of the coupled SPPs at the entrances of the rear grating, the higher the transmittance can be achieved. Basing on this property, an effective OUD example was achieved by exploring the intensity difference at the entrances of the rear gratings between the two incidences of opposite directions. In this kind of OUD, the positive transmittance can exceed 80 % and the difference between the transmittances of the two opposite directions can be as large as 63 %. The detailed design process was also presented.

  18. Chiral metamaterials: from optical activity and negative refractive index to asymmetric transmission

    International Nuclear Information System (INIS)

    Li, Zhaofeng; Mutlu, Mehmet; Ozbay, Ekmel

    2013-01-01

    We summarize the progress in the development and application of chiral metamaterials. After a brief review of the salient features of chiral metamaterials, such as giant optical activity, circular dichroism, and negative refractive index, the common method for the retrieval of effective parameters for chiral metamaterials is surveyed. Then, we introduce some typical chiral structures, e.g., chiral metamaterial consisting of split ring resonators, complementary chiral metamaterial, and composite chiral metamaterial, on the basis of the studies of the authors’ group. The coupling effect during the construction of bulk chiral metamaterials is mentioned and discussed. We introduce the application of bianisotropic chiral structures in the field of asymmetric transmission. Finally, we mention a few directions for future research on chiral metamaterials. (review article)

  19. Design and optical performance of a nonimaging Fresnel transmissive concentrator for building integration applications

    Energy Technology Data Exchange (ETDEWEB)

    Chemisana, Daniel, E-mail: daniel.chemisana@macs.udl.cat [Applied Physics Section of the Polytechnic School (EPS), University of Lleida, 25001 Lleida (Spain); Ignasi Rosell, Joan [Applied Physics Section of the Polytechnic School (EPS), University of Lleida, 25001 Lleida (Spain)

    2011-09-15

    Highlights: {yields} The designed concentrator has an important potential for building integration. {yields} The device concentrates radiation toward a static receiver. {yields} Tracking performed by a single driver, representing an important mechanical advantage. {yields} The system reaches a global optical efficiency value of 56.38%. - Abstract: A transmissive Fresnel reflector is designed to match the needs of building integration for concentrating photovoltaic (PV), thermal (T) or hybrid photovoltaic/thermal (PVT) generation. The device concentrates radiation toward a static receiver by means of an array of reflectors which rotate collectively. All rotation axes are coplanar and parallel. A deep analytical ray tracing study has been made of the design characteristics and concentrator performance, thus determining the configuration which optimises efficiency. Numerous ray tracing numerical simulations have been performed which contrast and support the analytical results.

  20. Design and optical performance of a nonimaging Fresnel transmissive concentrator for building integration applications

    International Nuclear Information System (INIS)

    Chemisana, Daniel; Ignasi Rosell, Joan

    2011-01-01

    Highlights: → The designed concentrator has an important potential for building integration. → The device concentrates radiation toward a static receiver. → Tracking performed by a single driver, representing an important mechanical advantage. → The system reaches a global optical efficiency value of 56.38%. - Abstract: A transmissive Fresnel reflector is designed to match the needs of building integration for concentrating photovoltaic (PV), thermal (T) or hybrid photovoltaic/thermal (PVT) generation. The device concentrates radiation toward a static receiver by means of an array of reflectors which rotate collectively. All rotation axes are coplanar and parallel. A deep analytical ray tracing study has been made of the design characteristics and concentrator performance, thus determining the configuration which optimises efficiency. Numerous ray tracing numerical simulations have been performed which contrast and support the analytical results.

  1. Gigabit Ethernet signal transmission using asynchronous optical code division multiple access.

    Science.gov (United States)

    Ma, Philip Y; Fok, Mable P; Shastri, Bhavin J; Wu, Ben; Prucnal, Paul R

    2015-12-15

    We propose and experimentally demonstrate a novel architecture for interfacing and transmitting a Gigabit Ethernet (GbE) signal using asynchronous incoherent optical code division multiple access (OCDMA). This is the first such asynchronous incoherent OCDMA system carrying GbE data being demonstrated to be working among multi-users where each user is operating with an independent clock/data rate and is granted random access to the network. Three major components, the GbE interface, the OCDMA transmitter, and the OCDMA receiver are discussed in detail. The performance of the system is studied and characterized through measuring eye diagrams, bit-error rate and packet loss rate in real-time file transfer. Our Letter also addresses the near-far problem and realizes asynchronous transmission and detection of signal.

  2. Doubling transmission capacity in optical wireless system by antenna horizontal- and vertical-polarization multiplexing.

    Science.gov (United States)

    Li, Xinying; Yu, Jianjun; Zhang, Junwen; Dong, Ze; Chi, Nan

    2013-06-15

    We experimentally demonstrate 2×56 Gb/s two-channel polarization-division-multiplexing quadrature-phase-shift-keying signal delivery over 80 km single-mode fiber-28 and 2 m Q-band (33-50 GHz) wireless link, adopting antenna horizontal- (H-) and vertical-polarization (V-polarization) multiplexing. At the wireless receiver, classic constant-modulus-algorithm equalization based on digital signal processing can realize polarization demultiplexing and remove the crosstalk at the same antenna polarization. By adopting antenna polarization multiplexing, the signal baud rate and performance requirements for optical and wireless devices can be reduced but at the cost of double antennas and devices, while wireless transmission capacity can also be increased but at the cost of stricter requirements for V-polarization. The isolation is only about 19 dB when V-polarization deviation approaches 10°, which will affect high-speed (>50 Gb/s) wireless delivery.

  3. On the reduced-complexity of LDPC decoders for ultra-high-speed optical transmission.

    Science.gov (United States)

    Djordjevic, Ivan B; Xu, Lei; Wang, Ting

    2010-10-25

    We propose two reduced-complexity (RC) LDPC decoders, which can be used in combination with large-girth LDPC codes to enable ultra-high-speed serial optical transmission. We show that optimally attenuated RC min-sum sum algorithm performs only 0.46 dB (at BER of 10(-9)) worse than conventional sum-product algorithm, while having lower storage memory requirements and much lower latency. We further study the use of RC LDPC decoding algorithms in multilevel coded modulation with coherent detection and show that with RC decoding algorithms we can achieve the net coding gain larger than 11 dB at BERs below 10(-9).

  4. Fiber-optic dipping liquid analyzer: theoretical and experimental study of light transmission

    International Nuclear Information System (INIS)

    Zhou Ai; Liu Zhihai; Yuan Libo

    2009-01-01

    A fiber-optic dipping liquid analyzer (FDLA) is developed for measuring liquid properties such as concentration, refractive index, surface tension, and viscosity. An important feature of the FDLA is that a liquid drop is introduced on the end face of a fiber probe, and the drop can be regarded as a planar-convex lens. The light transmitting path and receiving power are affected by the refractive index of the liquid drop. We present a theoretical and experimental analysis of the light transmission. A mathematical model of receiving power is established based on paraxial refraction imaging and fiber reflective intensity modulation methods. Sucrose-water solutions were tested with the FDLA. The experimental results agree well with the theoretical analysis.

  5. Full-field optical thickness profilometry of semitransparent thin films with transmission densitometry

    International Nuclear Information System (INIS)

    Johnson, Jay; Harris, Tequila

    2010-01-01

    A novel bidirectional thickness profilometer based on transmission densitometry was designed to measure the localized thickness of semitransparent films on a dynamic manufacturing line. The densitometer model shows that, for materials with extinction coefficients between 0.3 and 2.9 D/mm, 100-500 μm measurements can be recorded with less than ±5% error at more than 10,000 locations in real time. As a demonstration application, the thickness profiles of 75 mmx100 mm regions of polymer electrolyte membrane (PEM) were determined by converting the optical density of the sample to thickness with the Beer-Lambert law. The PEM extinction coefficient was determined to be 1.4 D/mm, with an average thickness error of 4.7%.

  6. Study of Transitions between Wetting States on Microcavity Arrays by Optical Transmission Microscopy

    DEFF Research Database (Denmark)

    Søgaard, Emil; Andersen, Nis Korsgaard; Smistrup, Kristian

    2014-01-01

    In this article, we present a simple and fast optical method based on transmission microscopy to study the stochastic wetting transitions on micro- and nanostructured polymer surfaces immersed in water. We analyze the influence of immersion time and the liquid pressure on the degree of water......-Laplace equation for the water menisci in the cavities and the diffusion of dissolved gas molecules in the water. In addition, the wetting transitions had a stochastic nature, which resulted from the short diffusion distance for dissolved gas molecules in the water between neighboring cavities. Furthermore, we...... compared the contact angle properties of two polymeric materials (COC and PP) with moderate hydrophobicity. We attributed the difference in the water repellency of the two materials to a difference in the wetting of their nanostructures. Our experimental observations thus indicate that both the diffusion...

  7. Experimental and simulation analysis of the W-band SC-FDMA hybrid optical-wireless transmission

    DEFF Research Database (Denmark)

    Dogadaev, Anton Konstantinovich; Pang, Xiaodan; Deng, Lei

    2014-01-01

    We report on the experimental demonstration of the W-band hybrid optical-wireless SC-FDMA with 1.49 Gbit/s transmission over up to 2.3 m of air propagation. Provided simulation performance analysis proves a potential to reach 12.1 Gbit/s.......We report on the experimental demonstration of the W-band hybrid optical-wireless SC-FDMA with 1.49 Gbit/s transmission over up to 2.3 m of air propagation. Provided simulation performance analysis proves a potential to reach 12.1 Gbit/s....

  8. ImNet: a fiber optic network with multistar topology for high-speed data transmission

    Science.gov (United States)

    Vossebuerger, F.; Keizers, Andreas; Soederman, N.; Meyer-Ebrecht, Dietrich

    1993-10-01

    ImNet is a fiber-optic local area network, which has been developed for high speed image communication in Picture Archiving and Communication Systems (PACS). A comprehensive analysis of image communication requirements in hospitals led to the conclusion that there is a need for networks which are optimized for the transmission of large datafiles. ImNet is optimized for this application in contrast to current-state LANs. ImNet consists of two elements: a link module and a switch module. The point-to-point link module can be up to 4 km by using fiber optic cable. For short distances up to 100 m a cheaper module using shielded twisted pair cable is available. The link module works bi-directionally and handles all protocols up to OSI-Level 3. The data rate per link is up to 140 MBit/s (clock rate 175 MHz). The switch module consists of the control unit and the cross-point-switch array. The array has up to fourteen interfaces for link modules. Up to fourteen data transfers each with a maximal transfer rate of 400 MBit/s can be handled at the same time. Thereby the maximal throughput of a switch module is 5.6 GBit/s. Out of these modules a multi-star network can be built i.e., an arbitrary tree structure of stars. This topology allows multiple transmissions at the same time as long as they do not require identical links. Therefore the overall throughput of ImNet can be a multiple of the datarate per link.

  9. An HST/STIS Optical Transmission Spectrum of Warm Neptune GJ 436b

    Science.gov (United States)

    Lothringer, Joshua D.; Benneke, Björn; Crossfield, Ian J. M.; Henry, Gregory W.; Morley, Caroline; Dragomir, Diana; Barman, Travis; Knutson, Heather; Kempton, Eliza; Fortney, Jonathan; McCullough, Peter; Howard, Andrew W.

    2018-02-01

    GJ 436b is a prime target for understanding warm Neptune exoplanet atmospheres and a target for multiple James Webb Space Telescope (JWST) Guaranteed Time Observation programs. Here, we report the first space-based optical transmission spectrum of the planet using two Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) transit observations from 0.53 to 1.03 μm. We find no evidence for alkali absorption features, nor evidence of a scattering slope longward of 0.53 μm. The spectrum is indicative of moderate to high metallicity (∼100–1000× solar), while moderate-metallicity scenarios (∼100× solar) require aerosol opacity. The optical spectrum also rules out some highly scattering haze models. We find an increase in transit depth around 0.8 μm in the transmission spectra of three different sub-Jovian exoplanets (GJ 436b, HAT-P-26b, and GJ 1214b). While most of the data come from STIS, data from three other instruments may indicate this is not an instrumental effect. Only the transit spectrum of GJ 1214b is well fit by a model with stellar plages on the photosphere of the host star. Our photometric monitoring of the host star reveals a stellar rotation rate of 44.1 days and an activity cycle of 7.4 years. Intriguingly, GJ 436 does not become redder as it gets dimmer, which is expected if star spots were dominating the variability. These insights into the nature of the GJ 436 system help refine our expectations for future observations in the era of JWST, whose higher precision and broader wavelength coverage will shed light on the composition and structure of GJ 436b’s atmosphere.

  10. Possibilities and limitations of optical fibers for the transmission of excimer laser radiation

    International Nuclear Information System (INIS)

    Klein, K.F.; Hillrichs, G.; Karlitschek, P.; Mann, K.

    1997-01-01

    For fiber-delivery systems with UV-lasers the candidates are mainly optical fibers with an undoped high-OH silica core and a F-doped silica cladding. However, there are three important limits to UV-applications: surface damage, two-photon-absorption and defect-generation during operation. In the last two years, UV-improved fibers with significantly reduced defects have been developed. This improvement is most pronounced at 248 and 193 nm, because at these critical wavelengths the induced losses are strongly influenced by the main broadband UV-defects with absorption maxima at 165 nm and 215 nm. We will summarize the results including the influence of the main parameters. In addition, the transmission capacity for the 308 nm wavelength is of interest due to medical and industrial applications. At this wavelength the influence of the nonlinearities is much lower; however, the induced losses in standard fibers are still an important factor. To show the advantages of the UV-improved fibers, the transmission characteristics at 308 nm wavelength will be described in more detail, for the first time

  11. Advanced Design of the First Quasi-optical Transmission Line for ECRH at TJ-II

    International Nuclear Information System (INIS)

    Fernandez, A.; Likin, K.; Martin, R.

    1999-01-01

    TJ-II plasma start-up and heating are made by electron cyclotron resonance waves at the second harmonic of the electron cyclotron frequency. The microwave power of the gyrotrons is transmitted by two quasi-optical transmission lines. The first line launches the microwave power under fixed injection geometry, i. e. there is no a possibility to change the launching angle the wave polarization. Due to the long distance between the last focusing mirror and the center TJ-II vessel the beam is quite wide at plasma border. The second line has a moveable mirror installed inside the TJ-II vessel. To get high absorption efficiency and a narrow energy deposition profile the internal mirror focuses the wave beam at plasma center. The beam width is about 2 cm. To get more flexibility in experiments on heating and current drive the first transmission line needs to be upgraded. The designs is presented in this report. It includes and internal mirror to focus the beam and to change the injection angle. A polarizer consisting in two corrugated mirrors will be incorporated to get any wave polarization. Two mirrors with an array of coupling holes and calorimetric measurements of the energy absorbed in the barrier window will permit the estimation of the microwave power launched the TJ-II. (Author) 13 refs

  12. Optical transmission of silica glass during swift-heavy-ion implantation

    International Nuclear Information System (INIS)

    Plaksin, Oleg; Okubo, Nariaki; Takeda, Yoshihiko; Amekura, Hiroshi; Kono, Kenichiro; Kishimoto, Naoki

    2004-01-01

    Metal nanoparticles fabricated by heavy-ion implantation of insulators are promising for non-linear optical applications. Spectra of optical transmission of silica glass in the visible region were measured during and after implantation of 3 MeV Cu 2+ ions. Three absorption bands contribute to the spectra: transient absorption (TA) at 2.34 eV, a surface plasmon resonance (SPR) peak at 2.21 eV and a tail of residual absorption (RA), which increases when the photon energy is increased from 2.2 to 2.6 eV. The TA and a change of the SPR peak strongly contribute to the total transient absorption obtained as the difference in absorption during and after irradiation. The effect of RA shows up as a decrease of absorption after switching on the ion beam. The TA provides a means for selective electronic excitation by a laser during implantation of silica glass. The precipitation of Cu atoms and the growth of Cu nanoparticles are well distinguishable stages of nanoparticle formation. The SPR peak appears at a fluence of 3.3 x 10 16 ions/cm 2 , corresponding to the onset of precipitation. At fluences higher than 3.4 x 10 16 ions/cm 2 , when the growth of nanoparticles predominates, the fluence dependence of the SPR peak is linear

  13. Graphene as transmissive electrodes and aligning layers for liquid-crystal-based electro-optic devices.

    Science.gov (United States)

    Basu, Rajratan; Shalov, Samuel A

    2017-07-01

    In a conventional liquid crystal (LC) cell, polyimide layers are used to align the LC homogeneously in the cell, and transmissive indium tin oxide (ITO) electrodes are used to apply the electric field to reorient the LC along the field. It is experimentally presented here that monolayer graphene films on the two glass substrates can function concurrently as the LC aligning layers and the transparent electrodes to fabricate an LC cell, without using the conventional polyimide and ITO substrates. This replacement can effectively decrease the thickness of all the alignment layers and electrodes from about 100 nm to less than 1 nm. The interaction between LC and graphene through π-π electron stacking imposes a planar alignment on the LC in the graphene-based cell-which is verified using a crossed polarized microscope. The graphene-based LC cell exhibits an excellent nematic director reorientation process from planar to homeotropic configuration through the application of an electric field-which is probed by dielectric and electro-optic measurements. Finally, it is shown that the electro-optic switching is significantly faster in the graphene-based LC cell than in a conventional ITO-polyimide LC cell.

  14. Optical transmission of low-level signals with high dynamic range using the optically-coupled current-mirror architecture

    Energy Technology Data Exchange (ETDEWEB)

    Camin, Daniel V. [Dipartimento di Fisica dell' Universita degli Studi di Milano and INFN, Milan (Italy)]. E-mail: Daniel.Victor.Camin@mi.infn.it; Grassi, Valerio [Dipartimento di Fisica dell' Universita degli Studi di Milano and INFN, Milan (Italy); De Donato, Cinzia [Dipartimento di Fisica dell' Universita degli Studi di Milano and INFN, Milan (Italy)

    2007-03-01

    In this paper we illustrate the application of a novel circuit architecture, the Optically-Coupled Current-Mirror (OCCM), conceived for the linear transmission of analogue signals via fibre optics. We installed 880 OCCMs in the PMTs of the first two telescopes of the cosmic-ray experiment Pierre Auger. The Pierre Auger Observatory (PAO) has been designed to increase the statistics of cosmic-rays with energies above 10{sup 18}eV. Two different techniques have been adopted: the Surface Detector (SD) modules that comprise 1600 tanks spaced each other by 1.5km within an area of 3000km{sup 2}. On the other side there are four buildings, the Optical Stations (OS), in which six telescopes are installed in each one of the four OS, at the periphery of the site, looking inwards. The telescopes are sensitive to the UV light created at the moment a high-energy shower develops in the atmosphere and is within the field-of-view (FOV) of the telescopes. The PAO is located in the Northern Patagonia, not far from the Cordillera de Los Andes, in Argentina. Both detector types, FD telescopes and SD modules, are sensitive to the UV light resulting from the interaction of high-energy particles and the nitrogen molecules in the atmosphere. The UV-sensitive telescopes operate only at night when the sky is completely dark. Otherwise, the light collected by the telescopes may give origin to severe damage in particular if those telescopes point at twilight or to artificial light sources. The duty cycle of the telescope's operation is therefore limited to about 10% or slightly more than that, if data are taken also when there is a partial presence of the Moon. The SD modules establish, independently of the telescopes, the geometry of the event. At the same time a shower reconstruction is performed using the telescope's data, independently of the SD modules. Use of both sets of data, taken by the FD telescopes and by the SD modules, allows the hybrid reconstruction that significantly

  15. Optical transmission of low-level signals with high dynamic range using the optically-coupled current-mirror architecture

    International Nuclear Information System (INIS)

    Camin, Daniel V.; Grassi, Valerio; De Donato, Cinzia

    2007-01-01

    In this paper we illustrate the application of a novel circuit architecture, the Optically-Coupled Current-Mirror (OCCM), conceived for the linear transmission of analogue signals via fibre optics. We installed 880 OCCMs in the PMTs of the first two telescopes of the cosmic-ray experiment Pierre Auger. The Pierre Auger Observatory (PAO) has been designed to increase the statistics of cosmic-rays with energies above 10 18 eV. Two different techniques have been adopted: the Surface Detector (SD) modules that comprise 1600 tanks spaced each other by 1.5km within an area of 3000km 2 . On the other side there are four buildings, the Optical Stations (OS), in which six telescopes are installed in each one of the four OS, at the periphery of the site, looking inwards. The telescopes are sensitive to the UV light created at the moment a high-energy shower develops in the atmosphere and is within the field-of-view (FOV) of the telescopes. The PAO is located in the Northern Patagonia, not far from the Cordillera de Los Andes, in Argentina. Both detector types, FD telescopes and SD modules, are sensitive to the UV light resulting from the interaction of high-energy particles and the nitrogen molecules in the atmosphere. The UV-sensitive telescopes operate only at night when the sky is completely dark. Otherwise, the light collected by the telescopes may give origin to severe damage in particular if those telescopes point at twilight or to artificial light sources. The duty cycle of the telescope's operation is therefore limited to about 10% or slightly more than that, if data are taken also when there is a partial presence of the Moon. The SD modules establish, independently of the telescopes, the geometry of the event. At the same time a shower reconstruction is performed using the telescope's data, independently of the SD modules. Use of both sets of data, taken by the FD telescopes and by the SD modules, allows the hybrid reconstruction that significantly improves the data

  16. Some fundamental problems relating to optical fibres. II. The ultimate bandwidth performance of optical fibre transmission lines

    International Nuclear Information System (INIS)

    Gambling, W.A.

    1977-01-01

    Optical fibre transmission lines can be divided broadly into two types, namely single mode and multimode. The bandwidth of the former is limited by the variation in group velocity with frequency caused by mode dispersion and material dispersion, with predicted values of tens of gigahertz over tens of kilometres for a monochromatic carrier, falling to approximately l GHz over 1km for a typical injection laser. Multimode fibres have the additional limitation of group delay between the various propagating modes. Several schemes have been suggested for reducing this effect, such as: (a) exciting only a few modes (ideally one) in a fibre exhibiting no mode conversion, (b) inducing coupling between bound modes but not into radiating modes, and (c) equalizing the mode velocities by means of a suitable refractive index profile. Most effort is presently being devoted to (c) and it has been shown that the optimum profile is affected by leaky modes and material dispersion. By operating at a wavelength in the region of 1.25μm the effect of material dispersion can be greatly reduced and bandwidths in excess of 1 GHz over 1km might be expected, even with sources of large linewidth. (author)

  17. Optical properties of Lactuca and Taraxacum seed and fruit coats: Their role as light filters [phytochrome, photoblasty, fiber optics, transmission, spectra

    International Nuclear Information System (INIS)

    Widell, K.-O.; Vogelmann, T.C.

    1985-01-01

    The optical properties of seed and fruit coats were examined from several varieties of light-sensitive achenes. Taraxacum vulgare L. and Lactuca sativa L. cv. Grand Rapids achenes with dark fruit coats and L. sativa cvs Huvudsallat and Issallat with white fruit coats were examined. Transmission spectra varied among the different achenes: white fruit coats of Lactuca acted as neutral density filters between 450 and 780 nm, whereas Taraxacum transmitted 2–36% in this region. The ribbed fruit coat structure greatly affected transmission so that at different locations in the same coat, transmission varied between 20 to 80% at 660 and 730 nm. Fruit coats of Grand Rapids lettuce and Taraxacum transmitted more far-red than red light with T 660 /T 730 ratios of 0.8 and 0.4, respectively. The relationship between the optical properties of fruit coats and light-stimulated germination is discussed. (author)

  18. 40-Gb/s transmission over 100m graded-index plastic optical fiber based on discrete multitone modulation

    NARCIS (Netherlands)

    Yang, H.; Lee, S.C.J.; Tangdiongga, E.; Breyer, F.; Randel, S.; Koonen, A.M.J.

    2009-01-01

    Spectral-efficient 40-Gb/s discrete multitone transmission over 100m of graded-index plastic optical fiber is experimentally demonstrated by intensity-modulation of a 10-GHz DFB-laser (1302nm) and direct-detection with a 25-µm large diameter photodetector.

  19. Demonstration of Cascaded In-Line Single-Pump Fiber Optical Parametric Amplifiers in Recirculating Loop Transmission

    DEFF Research Database (Denmark)

    Lali-Dastjerdi, Zohreh; Ozolins, Oskars; An, Yi

    2012-01-01

    The performance of cascaded single-pump fiber optical parametric amplifiers (FOPAs) is experimentally studied for the first time using recirculating loop transmission with 80-km dispersion managed spans. Error-free performance has been achieved over 320 km for 40-Gbit/s CSRZ-OOK and CSRZ...

  20. A Novel Noise Free Transmission Technique for Designing 100Gb/s Future Generation Optical Communication System

    DEFF Research Database (Denmark)

    Das, Bhagwan; Abdullah, M.F.L.; Pandey, Bishwajeet

    2017-01-01

    Differential Phase Shift Keying (DPSK) techniques are widely used in designing the high-speed communication systems. However, these techniques still need improvement for long haul communication system design. In this paper, high-speed optical signal transmission and reception system is achieved f...

  1. Low cost Polymer Optical Fibre based transmission system for feeding integrated broadband wireless in-house LANs

    NARCIS (Netherlands)

    Ng'Oma, A.; Koonen, A.M.J.; Tafur Monroy, I.; Boom, van den H.P.A.; Smulders, P.F.M.; Khoe, G.D.; Visser, D. Taco; Lenstra, Daan; Schouten, F. Hugo

    2002-01-01

    A bi-directional transmission system using low cost Polymer Optical Fibre (POF) to feed the required large number of radio access points in next-generation integrated broadband wireless in-house LANs is proposed. Results from simulations and experiments show that, by tuning system parameters, a

  2. Experimental Investigation of transmission properties of all-optical label swapping of orthogonal IM/FSK labeled signals

    DEFF Research Database (Denmark)

    Holm-Nielsen, Pablo Villanueva; Chi, Nan; Zhang, Jianfeng

    2003-01-01

    Optically labeled IM/FSK signal saretran smitte dover 50km of SMF under different compensation schemes.All-opticallabel swapping based on MZ-SOA and EAM is presented. Transmission followed by label swapping shows a 2dB overall power penalty....

  3. An RGB approach to extraordinary spectra

    Science.gov (United States)

    Grusche, Sascha; Theilmann, Florian

    2015-09-01

    After Newton had explained a series of ordinary spectra and Goethe had pointed out its complementary counterpart, Nussbaumer discovered a series of extraordinary spectra which are geometrically identical and colourwise analogous to Newton’s and Goethe’s spectra. To understand the geometry and colours of extraordinary spectra, the wavelength composition is explored with filters and spectroscopic setups. Visualized in a dispersion diagram, the wavelength composition is interpreted in terms of additive colour mixing. Finally, all spectra are simulated as the superposition of red, green, and blue images that are shifted apart. This RGB approach makes it easy to understand the complex relationship between wavelengths and colours.

  4. Optical transmission of nematic liquid crystal 5CB doped by single-walled and multi-walled carbon nanotubes.

    Science.gov (United States)

    Lisetski, L N; Fedoryako, A P; Samoilov, A N; Minenko, S S; Soskin, M S; Lebovka, N I

    2014-08-01

    Comparative studies of optical transmission of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), dispersed in nematic liquid crystal matrix 5CB, were carried out. The data evidence violations of Beer-Lambert-Bouguer (BLB) law both in cell thickness and concentration dependencies. The most striking is the fact that optical transmission dependencies for SWCNTs and MWCNTs were quite different in the nematic phase, but they were practically indistinguishable in the isotropic phase. Monte Carlo simulations of the impact of aggregation on direct transmission and violation of BLB law were also done. The results were discussed accounting for the tortuous shape of CNTs, their physical properties and aggregation, as well as strong impact of perturbations of the nematic 5CB structure inside coils and in the vicinity of CNT aggregates.

  5. Deeply-etched micromirror with vertical slit and metallic coating enabling transmission-type optical MEMS filters

    Science.gov (United States)

    Othman, Muhammad A.; Sabry, Yasser M.; Sadek, Mohamed; Nassar, Ismail M.; Khalil, Diaa A.

    2016-03-01

    In this work we report a novel optical MEMS deeply-etched mirror with metallic coating and vertical slot, where the later allows reflection and transmission by the micromirror. The micromirror as well as fiber grooves are fabricated using deep reactive ion etching technology, where the optical axis is in-plane and the components are self-aligned. The etching depth is 150 μm chosen to improve the micromirror optical throughput. The vertical optical structure is Al metal coated using the shadow mask technique. A fiber-coupled Fabry-Pérot filter is successfully realized using the fabricated structure. Experimental measurements were obtained based on a dielectric-coated optical fiber inserted into a fiber groove facing the slotted micromirror. A versatile performance in terms of the free spectral range and 3-dB bandwidth is achieved.

  6. On the reduced-complexity of LDPC decoders for beyond 400 Gb/s serial optical transmission

    Science.gov (United States)

    Djordjevic, Ivan B.; Xu, Lei; Wang, Ting

    2010-12-01

    Two reduced-complexity (RC) LDPC decoders are proposed, which can be used in combination with large-girth LDPC codes to enable beyond 400 Gb/s serial optical transmission. We show that optimally attenuated RC min-sum sum algorithm performs only 0.45 dB worse than conventional sum-product algorithm, while having lower storage memory requirements and much lower latency. We further evaluate the proposed algorithms for use in beyond 400 Gb/s serial optical transmission in combination with PolMUX 32-IPQ-based signal constellation and show that low BERs can be achieved for medium optical SNRs, while achieving the net coding gain above 11.4 dB.

  7. Extraordinary Readers: The Story of a Documentary

    Directory of Open Access Journals (Sweden)

    İsmail Arayıcı

    2013-11-01

    Full Text Available This article discusses the story behind the making of a documentary about the extraordinary patrons of public libraries located throughout Turkey. The documentary explored in this article was the result of collaboration between the Libraries of the Ministry of Culture and Tourism, the General Directorate of Libraries and Publications, and the Turkish Librarians' Association.

  8. Developing Concepts of Ordinary and Extraordinary Communication

    Science.gov (United States)

    Lane, Jonathan D.; Evans, E. Margaret; Brink, Kimberly A.; Wellman, Henry M.

    2016-01-01

    We examine how understandings of ordinary and extraordinary communication develop. Three- to 10-year-old children and adults (N = 183) were given scenarios in which a protagonist wanted help from a human (their parent) or from God. Scenarios varied in whether protagonists expressed their desires aloud (by asking) or silently (by hoping), whether…

  9. Nakula's Extraordinary Talent Mathematics From the Mahabharatha

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 1. Nakula's Extraordinary Talent Mathematics From the Mahabharatha. C Musili. General Article Volume 2 Issue 1 January 1997 pp 44-52. Fulltext. Click here to view fulltext PDF. Permanent link:

  10. Descriptive parameters of the erythrocyte aggregation phenomenon using a laser transmission optical chip

    Science.gov (United States)

    Toderi, Martín A.; Castellini, Horacio V.; Riquelme, Bibiana D.

    2017-01-01

    The study of red blood cell (RBC) aggregation is of great interest because of its implications for human health. Altered RBC aggregation can lead to microcirculatory problems as in vascular pathologies, such as hypertension and diabetes, due to a decrease in the erythrocyte surface electric charge and an increase in the ligands present in plasma. The process of erythrocyte aggregation was studied in stasis situation (free shear stresses), using an optical chip based on the laser transmission technique. Kinetic curves of erythrocyte aggregation under different conditions were obtained, allowing evaluation and characterization of this process. Two main characteristics of blood that influence erythrocyte aggregation were analyzed: the erythrocyte surface anionic charge (EAC) after digestion with the enzyme trypsin and plasmatic protein concentration in suspension medium using plasma dissolutions in physiological saline with human albumin. A theoretical approach was evaluated to obtain aggregation and disaggregation ratios by syllectograms data fitting. Sensible parameters (Amp100, t) regarding a reduced erythrocyte EAC were determined, and other parameters (AI, M-Index) resulted that are representative of a variation in the plasmatic protein content of the suspension medium. These results are very useful for further applications in biomedicine.

  11. A linear laser-driver array for optical transmission in the LHC experiments

    CERN Document Server

    Cervelli, G; Moreira, P; Vasey, F

    2000-01-01

    A 4-way linear laser driver has been designed and implemented in a commercial 0.25 mu m CMOS technology. The full-custom IC is intended for analogue and digital data transmission as part of the 50 000 optical fibre links of the CMS particle tracking system. Intrinsic radiation tolerance and specific design methodologies enable the device to operate over 10 years in the harsh radiation environment of the innermost LHC detectors. Although optimised for analogue operation the driver is compatible with LVDS digital signalling. A combination of linearization methods achieves good analogue performance (8-bit equivalent dynamic range with a bandwidth of 100 MHz), while maintaining wide input common-mode range (+or-350 mV) and limited power dissipation. The linearly amplified signal is added to a DC current, which can be set over a wide range (-60 mA to +60 mA). The latter capability allows tracking of changes in laser threshold due to ageing or radiation damage. The driver gain and bias current are set via a serial ...

  12. Infrared optical constants of liquid palm oil and palm oil biodiesel determined by the combined ellipsometry-transmission method.

    Science.gov (United States)

    Wang, C C; Tan, J Y; Ma, Y Q; Liu, L H

    2017-06-20

    The optical constants of vegetable oils and biodiesels are the basic input parameters in the study of the thermal radiation transfer and monitoring the productivity of vegetable oils converting to biodiesels. In this work, a combined ellipsometry-transmission method is presented to obtain the optical constants of palm oil and palm oil biodiesel between 20°C and 150°C in the spectral range 600-4100  cm -1 and to study the temperature effect on the optical constants. In the combined method, a modified ellipsometry method is used to measure the optical constants of palm oil and palm oil biodiesel for the whole researched wave bands. For the weak absorption regions in which the ellipsometry method cannot give precise absorption indices, the transmission method is conducted to get the absorption indices using the refractive indices obtained by the proposed ellipsometry method. Deionized water and methanol are taken as examples to verify the combined ellipsometry-transmission method. It is shown that the combined method can overcome the deficiencies of the traditional ellipsometry and transmission method, which can be used for the measurements of both strong and weak absorption wave bands. The experimental analyses indicate that temperature exerts a noticeable influence on the infrared optical constants of palm oil and palm oil biodiesel. With the increase of temperature, the refractive indices at certain wavenumbers decrease nearly linearly, and the amplitudes of dominant absorption peaks show a decreasing trend. The absorption peaks located around 3550  cm -1 show blueshift trends as temperature increases. Comparing these two kinds of oils, palm oil presents larger values in refractive indices and dominant absorption peaks.

  13. Ab initio analytical model of light transmission through a cylindrical subwavelength hole in an optically thick film

    DEFF Research Database (Denmark)

    Bordo, Vladimir

    2011-01-01

    The rigorous analytical theory of light transmission through a cylindrical hole of arbitrary diameter in an optically thick film is developed. The approach is based on the introduction of fictitious surface currents at both hole openings and both film surfaces. The solution of Maxwell’s equations...... the film thickness considerably exceeds the hole diameter. It is emphasized that a specific pole corresponding to excitation of surface plasmon polaritons does not appear in the analysis. The theory is illustrated by the calculation of light transmission through a subwavelength hole in an Ag film....

  14. Nanoimprint-defined, large-area meta-surfaces for unidirectional optical transmission with superior extinction in the visible-to-infrared range.

    Science.gov (United States)

    Yao, Yuhan; Liu, He; Wang, Yifei; Li, Yuanrui; Song, Boxiang; Wang, Richard P; Povinelli, Michelle L; Wu, Wei

    2016-07-11

    Optical devices with asymmetric transmission have important applications in optical systems, but optical isolators with the modal asymmetry can only be built using magneto-optical or nonlinear materials, as dictated by the Lorentz reciprocity theorem. However, optical devices with the power asymmetry can be achieved by linear materials such as metals and dielectrics. In this paper, we report a large-area, nanoimprint-defined meta-surface (stacked subwavelength gratings) with high-contrast asymmetric transmittance in the visible-to-infrared wavelength range for TM-polarized light. The physical origin of asymmetric transmission through the meta-surface is studied by analyzing the scattering matrix.

  15. Compensation of nonlinearity in a fiber-optic transmission system using frequency-degenerate phase conjugation through counter-propagating dual pump FWM in a semiconductor optical amplifier

    Science.gov (United States)

    Anchal, Abhishek; K, Pradeep Kumar; O'Duill, Sean; Anandarajah, Prince M.; Landais, Pascal

    2018-04-01

    We present a scheme of frequency-degenerate mid-span spectral inversion (MSSI) for nonlinearity compensation in fiber-optic transmission systems. The spectral inversion is obtained by using counter-propagating dual pump four-wave mixing in a semiconductor optical amplifier (SOA). Frequency-degeneracy between signal and conjugate is achieved by keeping two pump frequencies symmetrical about the signal frequency. We simulate the performance of MSSI for nonlinearity compensation by scrutinizing the improvement of the Q-factor of a 200 Gbps QPSK signal transmitted over a standard single mode fiber, as a function of launch power for different span lengths and number of spans. We demonstrate a 7.5 dB improvement in the input power dynamic range and an almost 83% increase in the transmission length for optimum MSSI parameters of -2 dBm pump power and 400 mA SOA current.

  16. Fiber-FSO/wireless convergent systems based on dual-polarization and one optical sideband transmission schemes

    Science.gov (United States)

    Huang, Xu-Hong; Lu, Hai-Han; Li, Chung-Yi; Wang, Yun-Chieh; Chang, Jen-Chieh; Jheng, Yu-Bo; Tsai, Wen-Shing

    2018-06-01

    A bidirectional fiber-free-space optical (FSO)/wireless convergent system that uses dual-polarization and one optical sideband transmission schemes for hybrid vestigial sideband (VSB)–four-level pulse amplitude modulation (PAM4)/millimeter-wave signal transmission is proposed and demonstrated. Using a dual-polarization scheme, one optical sideband that is modulated by a 56 Gb s‑1 VSB–PAM4 signal (x-polarization) and another optical sideband that is modulated by a 10 Gbps data stream (y-polarization) are separated and polarized orthogonally. One optical sideband modulated by a 10 Gbps data stream (y-polarization) is delivered to efficaciously suppress the dispersion-induced limitation due to a span of 40 km single-mode fiber (SMF) and the distortion due to the beating among multiple sidebands. The proposed bidirectional fiber-FSO/wireless convergent system is a prominent one for providing broadband integrated services, such as the Internet, telecommunication, and 5G mobile networks.

  17. Issues arising with the application of optical fiber transmission in class 1E systems in nuclear power plants

    International Nuclear Information System (INIS)

    Korsah, K.; Antonescu, C.

    1993-01-01

    The application of fiber optic links and networks in safety-critical systems in the next generation of nuclear power plants, as well as in some digital upgrades in present-day plants, will mean that these links must be highly reliable and able to withstand the effect of environmental stressors present at the installation location. This paper discusses the failure modes and age-related mechanisms of fiber optic transmission components and identifies environmental stressors that could adversely affect their reliability over the long term. Some of the standards that could be used in their qualification for safety-critical applications are also discussed briefly

  18. Demonstration of intradyne BPSK optical free-space transmission in representative atmospheric turbulence conditions for geostationary uplink channel.

    Science.gov (United States)

    Surof, Janis; Poliak, Juraj; Calvo, Ramon Mata

    2017-06-01

    Binary phase-shift keying optical transmission in the C-band with coherent intradyne reception is demonstrated over a long-range (10.45 km) link through the atmosphere. The link emulates representative channel conditions for geostationary optical feeder uplinks in satellite communications. The digital signal processing used in recovering the transmitted data and the performed measurements are described. Finally, the bit error rate results for 10 Gbit/s, 20 Gbit/s, and 30 Gbit/s of the outdoor experiments are presented and compared with back-to-back measurements and theory.

  19. Measurements of Effective Schottky Barrier in Inverse Extraordinary Optoconductance Structures

    Science.gov (United States)

    Tran, L. C.; Werner, F. M.; Solin, S. A.; Gilbertson, Adam; Cohen, L. F.

    2013-03-01

    Individually addressable optical sensors with dimensions as low as 250nm, fabricated from metal semiconductor hybrid structures (MSH) of AuTi-GaAs Schottky interfaces, display a transition from resistance decreasing with intensity in micron-scale sensors (Extraordinary Optoconductance, EOC) to resistance increasing with intensity in nano-scale sensors (Inverse Extraordinary Optoconductance I-EOC). I-EOC is attributed to a ballistic to diffusive crossover with the introduction of photo-induced carriers and gives rise to resistance changes of up to 9462% in 250nm devices. We characterize the photo-dependence of the effective Schottky barrier in EOC/I-EOC structures by the open circuit voltage and reverse bias resistance. Under illumination by a 5 mW, 632.8 nm HeNe laser, the barrier is negligible and the Ti-GaAs interface becomes Ohmic. Comparing the behavior of two devices, one with leads exposed, another with leads covered by an opaque epoxy, the variation in Voc with the position of the laser can be attributed to a photovoltaic effect of the lead metal and bulk GaAs. The resistance is unaffected by the photovoltaic offset of the leads, as indicated by the radial symmetry of 2-D resistance maps obtained by rastering a laser across EOC/IEOC devices. SAS has a financial interest in PixelEXX, a start-up company whose mission is to market imaging arrays.

  20. Effect of Er doping on optical transmission and EL spectra of (Zn, Cd)S:Cu phosphors

    International Nuclear Information System (INIS)

    Patil, P.K.; Nandgave, J.K.; Lawangar Pawar, R.D.

    1991-01-01

    Powder phosphors((Znsub(0.4)Cdsub(0.6))S)doped with Cu and Er have been prepared under the inert atmosphere of argon. The optical transmission spectra of Cu doped phosphors have been investigated and explained on the basis of copper associated defect states. The improvement of optical transmission of the phosphors due to Er doping has been reported and explained. The EL emission spectrum of (Znsub(0.4)Cdsub(0.6))S:Cu:Er phosphors exhibits two broad bands characteristic of Cu. The absence of characteristic Er bands has been explained as an effect of thermal quenching of Er donor levels. (author). 9 refs., 2 figs

  1. Transmission electron and optical microscopy of the domain structure of Ni3B7O13Br ferroic boracite

    International Nuclear Information System (INIS)

    Castellanos-Guzman, A.G.; Trujillo-Torrez, M.; Czank, M.

    2005-01-01

    The study investigated the domain structure of nickel bromine boracite single crystals, by means of polarised-light in conjunction with transmission electron microscopy. Single crystals of Ni 3 B 7 O 13 Br were grown by chemical transport reactions in closed quartz ampoules, in the temperature range of 1130 K and were examined by polarising optical microscopy (PLM), and transmission electron microscopy (TEM). PLM was also used in order to study the behaviour of birefringence as a function of temperature. For TEM the single crystals were crushed and mounted on holey carbon films. Comparative electron microscope images were useful for revealing the domain structure of this fully ferroelectric/fully ferroelastic material previously observed between the crossed polars of an optical microscope. X-ray diffraction analysis of the crystal under study was performed at room temperature

  2. Simultaneous transmission of the IEEE 802.11 radio signal and optical Gbit Ethernet over the multimode fiber link

    Science.gov (United States)

    Maksymiuk, L.; Podziewski, A.

    2015-09-01

    In the paper we present a successful joint transmission of the IEEE 802.11 signal and an optical Gbit Ethernet over a multimode fiber based link. Most importantly, the multiplexation of both signals was performed in the optical domain. Due to the utilization of the multimode fiber the OBI noise was avoided and both channels were able to operate at the same wavelength. We prove that potential RoF link for IEEE 802.11 signal distribution may be used to additionally transmit other signals as Gbit Ethernet and therefore utilize the fiber infrastructure installed more effectively. The qualities of both the IEEE 802.11 and Ethernet transmissions fulfilled the requirements imposed by appropriate standards.

  3. Ultra-precise measurement of optical aberrations for sub-Aangstroem transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Barthel, J.

    2008-06-15

    Quantitative investigations of material structures on an atomic scale by means of highresolution transmission electron microscopy (HRTEM) impose not only extreme demands on the mechanic and electromagnetic stability of the applied instruments but require also their precise electron-optical adjustment. Today a physical resolution well below one Aangstroem can be achieved with commercially available microscopes on a daily basis. However, the achieved resolution can often not be reliably exploited for the interpretation of the resulting microscopical data due to the presence of so-called higher-order lens aberrations. At the starting time of this work, a sufficiently accurate procedure to measure higher-order aberrations was urgently missing. Since aberration measurement is a mandatory prerequisite for any technique of aberration control enabling quantitative high-resolution microscopy, the goal of this work is to develop such a measurement procedure for the Sub-Aangstroem regime. The measurement procedures developed in the course of this work are based on the numerical evaluation of a series of images taken from an amorphous object under electron-beam illumination with varying tilt. New techniques have been developed for the evaluation of single images as well as for the optimised evaluation of the whole series. These procedures allow microscope users to perform quantitative HRTEM even at a resolution of 0.5 Aangstroem. The precision reached with the newly developed measurement procedures is unprecedented and surpasses existing solutions by at least one order of magnitude in any respect. All the concepts and procedures for aberration measurement developed in this work have been implemented in a software package which satisfies professional demands with respect to robustness, precision, speed and user-friendliness. The new automatic aberrationmeasurement procedures are suitable to establish HRTEM as a quantitative technique for material science investigations in the

  4. Ultra-precise measurement of optical aberrations for sub-Aangstroem transmission electron microscopy

    International Nuclear Information System (INIS)

    Barthel, J.

    2008-06-01

    Quantitative investigations of material structures on an atomic scale by means of highresolution transmission electron microscopy (HRTEM) impose not only extreme demands on the mechanic and electromagnetic stability of the applied instruments but require also their precise electron-optical adjustment. Today a physical resolution well below one Aangstroem can be achieved with commercially available microscopes on a daily basis. However, the achieved resolution can often not be reliably exploited for the interpretation of the resulting microscopical data due to the presence of so-called higher-order lens aberrations. At the starting time of this work, a sufficiently accurate procedure to measure higher-order aberrations was urgently missing. Since aberration measurement is a mandatory prerequisite for any technique of aberration control enabling quantitative high-resolution microscopy, the goal of this work is to develop such a measurement procedure for the Sub-Aangstroem regime. The measurement procedures developed in the course of this work are based on the numerical evaluation of a series of images taken from an amorphous object under electron-beam illumination with varying tilt. New techniques have been developed for the evaluation of single images as well as for the optimised evaluation of the whole series. These procedures allow microscope users to perform quantitative HRTEM even at a resolution of 0.5 Aangstroem. The precision reached with the newly developed measurement procedures is unprecedented and surpasses existing solutions by at least one order of magnitude in any respect. All the concepts and procedures for aberration measurement developed in this work have been implemented in a software package which satisfies professional demands with respect to robustness, precision, speed and user-friendliness. The new automatic aberrationmeasurement procedures are suitable to establish HRTEM as a quantitative technique for material science investigations in the

  5. Provisioning Strategies for Transparent Optical Networks Considering Transmission Quality, Security, and Energy Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Jirattigalachote, Amornrat

    2012-07-01

    The continuous growth of traffic demand driven by the brisk increase in number of Internet users and emerging online services creates new challenges for communication networks. The latest advances in Wavelength Division Multiplexing (WDM) technology make it possible to build Transparent Optical Networks (TONs) which are expected to be able to satisfy this rapidly growing capacity demand. The work in this thesis addresses three important aspects. In particular, this thesis focuses on routing and wavelength assignment (RWA) strategies specifically devised to target: (i) the lightpath transmission quality, (ii) the network security (i.e., in terms of vulnerability to physical-layer attacks), and (iii) the reduction of the network energy consumption. Our contributions are summarized below. A number of Impairment Constraint Based Routing (ICBR) algorithms have been proposed in the literature to consider physical-layer impairments during the connection provisioning phase. Their objective is to prevent the selection of optical connections (referred to as lightpaths) with poor signal quality. These ICBR approaches always assign each connection request the least impaired lightpath and support only a single threshold of transmission quality, used for all connection requests. However, next generation networks are expected to support a variety of services with disparate requirements for transmission quality. To address this issue, in this thesis we propose an ICBR algorithm supporting differentiation of services at the Bit Error Rate (BER) level, referred to as ICBR-Diff. Our approach takes into account the effect of physical-layer impairments during the connection provisioning phase where various BER thresholds are considered for accepting/blocking connection requests, depending on the signal quality requirements of the connection requests. We tested the proposed ICBR-Diff approach in different network scenarios, including also a fiber heterogeneity. It is shown that it can

  6. Transmission properties of a single metallic slit: from the subwavelength regime to the geometrical-optics limit.

    Science.gov (United States)

    Bravo-Abad, J; Martín-Moreno, L; García-Vidal, F J

    2004-02-01

    In this work we explore the transmission properties of a single slit in a metallic screen. We analyze the dependence of these properties on both slit width and angle of incident radiation. We study in detail the crossover between the subwavelength regime and the geometrical-optics limit. In the subwavelength regime, resonant transmission linked to the excitation of waveguide resonances is analyzed. Linewidth of these resonances and their associated electric-field intensities are controlled by just the width of the slit. More complex transmission spectra appear when the wavelength of light is comparable to the slit width. Rapid oscillations associated with the emergence of different propagating modes inside the slit are the main features appearing in this regime.

  7. Developing concepts of ordinary and extraordinary communication.

    Science.gov (United States)

    Lane, Jonathan D; Evans, E Margaret; Brink, Kimberly A; Wellman, Henry M

    2016-01-01

    We examine how understandings of ordinary and extraordinary communication develop. Three- to 10-year-old children and adults (N = 183) were given scenarios in which a protagonist wanted help from a human (their parent) or from God. Scenarios varied in whether protagonists expressed their desires aloud (by asking) or silently (by hoping), whether (for human scenarios) parents were nearby or far away, and whether (for God scenarios) protagonists expressed desires through ordinary means (asking or hoping) or more extraordinary means (praying). Following each scenario, participants were asked whether the recipient (either the parent or God) was aware of the protagonist's desire. Children as young as 3 to 4 years old understood that both loudness and distance limit the effectiveness of human communication, reporting that humans would most likely be aware of desires when they were expressed both aloud and nearby. As well, by this age children reported that God would more often be aware of desires than would humans, but children of all ages often reported that God (like humans) would be more aware of desires expressed aloud (rather than silently). These concepts of ordinary and extraordinary communication continued to be refined through middle childhood. Children's performance on standard theory-of-mind tasks and participants' religious background predicted whether they attributed awareness to God. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  8. Monolithically integrated quantum dot optical gain modulator with semiconductor optical amplifier for 10-Gb/s photonic transmission

    Science.gov (United States)

    Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Kawanishi, Tetsuya

    2015-03-01

    Short-range interconnection and/or data center networks require high capacity and a large number of channels in order to support numerous connections. Solutions employed to meet these requirements involve the use of alternative wavebands to increase the usable optical frequency range. We recently proposed the use of the T- and O-bands (Thousand band: 1000-1260 nm, Original band: 1260-1360 nm) as alternative wavebands because large optical frequency resources (>60 THz) can be easily employed. In addition, a simple and compact Gb/s-order high-speed optical modulator is a critical photonic device for short-range communications. Therefore, to develop an optical modulator that acts as a highfunctional photonic device, we focused on the use of self-assembled quantum dots (QDs) as a three-dimensional (3D) confined structure because QD structures are highly suitable for realizing broadband optical gain media in the T+O bands. In this study, we use the high-quality broadband QD optical gain to develop a monolithically integrated QD optical gain modulator (QD-OGM) device that has a semiconductor optical amplifier (QD-SOA) for Gb/s-order highspeed optical data generation in the 1.3-μm waveband. The insertion loss of the device can be compensated through the SOA, and we obtained an optical gain change of up to ~7 dB in the OGM section. Further, we successfully demonstrate a 10-Gb/s clear eye opening using the QD-OGM/SOA device with a clock-data recovery sequence at the receiver end. These results suggest that the monolithic QD-EOM/SOA is suitable for increasing the number of wavelength channels for smart short-range communications.

  9. One-way optical transmission in silicon photonic crystal heterojunction with circular and square scatterers

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dan, E-mail: liudanhu725@126.com [School of Physics and Mechanical & Electrical Engineering, Hubei University of Education, Wuhan, 430205 (China); Hu, Sen [School of Physics and Mechanical & Electrical Engineering, Hubei University of Education, Wuhan, 430205 (China); Gao, Yihua [Wuhan National Laboratory for Optoelectronics (WNLO), School of Physics, Huazhong University of Science and Technology (HUST), Wuhan, 430074 (China)

    2017-07-12

    A 2D orthogonal square-lattice photonic crystal (PC) heterojunction consisting of circular and square air holes in silicon is presented. Band structures are calculated using the plane wave expansion method, and the transmission properties are investigated by the finite-different time-domain simulations. Thanks to the higher diffraction orders excited when the circular and square holes are interlaced along the interface, one-way transmission phenomena can exist within wide frequency regions. The higher order diffraction is further enhanced through two different interface optimization designs proposed by modifying the PC structure of the hetero-interface. An orthogonal PC heterojunction for wide-band and efficient one-way transmission is constructed, and the maximum transmissivity is up to 78%. - Highlights: • Photonic crystal heterojunction with circular and square scatterers is first studied. • One-way transmission efficiency is closely related to the hetero-interface. • Wide-band and efficient one-way transmission is realized.

  10. Normal mode splitting and ground state cooling in a Fabry—Perot optical cavity and transmission line resonator

    International Nuclear Information System (INIS)

    Chen Hua-Jun; Mi Xian-Wu

    2011-01-01

    Optomechanical dynamics in two systems which are a transmission line resonator and Fabrya—Perot optical cavity via radiation—pressure are investigated by linearized quantum Langevin equation. We work in the resolved sideband regime where the oscillator resonance frequency exceeds the cavity linewidth. Normal mode splittings of the mechanical resonator as a pure result of the coupling interaction in the two optomechanical systems is studied, and we make a comparison of normal mode splitting of mechanical resonator between the two systems. In the optical cavity, the normal mode splitting of the movable mirror approaches the latest experiment very well. In addition, an approximation scheme is introduced to demonstrate the ground state cooling, and we make a comparison of cooling between the two systems dominated by two key factors, which are the initial bath temperature and the mechanical quality factor. Since both the normal mode splitting and cooling require working in the resolved sideband regime, whether the normal mode splitting influences the cooling of the mirror is considered. Considering the size of the mechanical resonator and precooling the system, the mechanical resonator in the transmission line resonator system is easier to achieve the ground state cooling than in optical cavity. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  11. Directional optical transmission through a sand layer: a preliminary laboratory experiment

    Science.gov (United States)

    Tian, Jia; Philpot, William D.

    2017-10-01

    Given the importance of penetration of light in the soil for seed germination, soil warming, and the photolytic degradation of pesticides, directional transmission of thin sand samples are studied in this paper under both dry and saturated conditions. The detector views upward through a glass-bottom sample holder, filled to 3 or 4 mm with a coarse, translucent, quartz sand sample. Transmission through the samples was measured as the illumination zenith angle moved from 0 to 70° in 5° intervals. In the most cases, transmission decreased monotonically, but slowly with increasing illumination angle at all wavelengths. A peak in transmission only appeared at 0° illumination for the low bulk density, dry sample at 3 mm depth. The 0° peak disappeared when the sample was wetted, when the bulk density increased, or when the depth of the sample increased, which indicates that the radiation transmitting through a sand layer can be diffused thoroughly with a millimeters-thin sand layer. For the saturated samples, water influences light transmission in contrasting ways in shorter and longer wavelength. Transmission increased in the VNIR when saturated relative to dry, while transmission decreased sharply after 1300 nm, with spectral absorption features characteristic of water absorption. In VNIR region, water absorption is low and the low relative index of refraction enhanced transmission through sand sample. In contrast, water absorption became dominant at longer wavelengths region leading to the strongly reduced transmission.

  12. Effects of fourth-order dispersion in very high-speed optical time-division multiplexed transmission.

    Science.gov (United States)

    Capmany, J; Pastor, D; Sales, S; Ortega, B

    2002-06-01

    We present a closed-form expression for computation of the output pulse's rms time width in an optical fiber link with up to fourth-order dispersion (FOD) by use of an optical source with arbitrary linewidth and chirp parameters. We then specialize the expression to analyze the effect of FOD on the transmission of very high-speed linear optical time-division multiplexing systems. By suitable source chirping, FOD can be compensated for to an upper link-length limit above which other techniques must be employed. Finally, a design formula to estimate the maximum attainable bit rate limited by FOD as a function of the link length is also presented.

  13. Influence of transmission bit rate on performance of optical fibre communication systems with direct modulation of laser diodes

    International Nuclear Information System (INIS)

    Ahmed, Moustafa F

    2009-01-01

    This paper reports on the influence of the transmission bit rate on the performance of optical fibre communication systems employing laser diodes subjected to high-speed direct modulation. The performance is evaluated in terms of the bit error rate (BER) and power penalty associated with increasing the transmission bit rate while keeping the transmission distance. The study is based on numerical analysis of the stochastic rate equations of the laser diode and takes into account noise mechanisms in the receiver. Correlation between BER and the Q-parameter of the received signal is presented. The relative contributions of the transmitter noise and the circuit and shot noises of the receiver to BER are quantified as functions of the transmission bit rate. The results show that the power penalty at BER = 10 -9 required to keep the transmission distance increases moderately with the increase in the bit rate near 1 Gbps and at high bias currents. In this regime, the shot noise is the main contributor to BER. At higher bit rates and lower bias currents, the power penalty increases remarkably, which comes mainly from laser noise induced by the pseudorandom bit-pattern effect.

  14. Optical true-time-delay microwave beam-steering with 1 Gb/s wireless transmission for in-building networks

    NARCIS (Netherlands)

    Cao, Z.; Li, F.; Boom, van den H.P.A.; Tangdiongga, E.; Koonen, A.M.J.

    2013-01-01

    An optical true time delay based microwave beam-steering (OTTD-MBS) scheme integrated with a radio-over-fibre system is demonstrated. Properties of 1Gb/s data wireless transmission with OTTD-MBS are studied.

  15. Extraordinary lateral beaming of sound from a square-lattice phononic crystal

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Xiaoxue; Qiu, Chunyin; He, Hailong; Peng, Shasha; Ke, Manzhu [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Liu, Zhengyou, E-mail: zyliu@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Institute for Advanced Studies, Wuhan University, Wuhan 430072 (China)

    2017-03-03

    Highlights: • An extraordinary lateral beaming phenomenon is observed in a finite phononic crystal made of square lattice. • The phenomenon can be explained by the equivalence of the states located around the four corners of the first Brillouin zone. • The lateral beaming behavior enables a simple design of acoustic beam splitters. • In some sense, the phenomenon can be described by a near zero refractive index. - Abstract: This work revisits the sound transmission through a finite phononic crystal of square lattice. In addition to a direct, ordinary transmission through the sample, an extraordinary lateral beaming effect is also observed. The phenomenon stems from the equivalence of the states located around the four corners of the first Brillouin zone. The experimental result agrees well with the theoretical prediction. The lateral beaming behavior enables a simple design for realizing acoustic beam splitters.

  16. Simultaneous transmission of 256-QAM WIMAX at 5.7GHz and optically generated impulse radio UWB over fiber for indoor wireless multi-services

    DEFF Research Database (Denmark)

    Yu, Xianbin; Yin, Xiaoli; Gibbon, Timothy Braidwood

    2010-01-01

    Fiber transmission of simultaneous optically generated FCC compliant 625Mbps impulse radio UWB and 80Mbps 256-QAM IEEE 802.16 WIMAX signals is experimentally demonstrated by using a single directly modulated light source.......Fiber transmission of simultaneous optically generated FCC compliant 625Mbps impulse radio UWB and 80Mbps 256-QAM IEEE 802.16 WIMAX signals is experimentally demonstrated by using a single directly modulated light source....

  17. 12.5 Gb/s multi-channel broadcasting transmission for free-space optical communication based on the optical frequency comb module.

    Science.gov (United States)

    Tan, Jun; Zhao, Zeping; Wang, Yuehui; Zhang, Zhike; Liu, Jianguo; Zhu, Ninghua

    2018-01-22

    A wide-spectrum, ultra-stable optical frequency comb (OFC) module with 100 GHz frequency intervals based on a quantum dot mode locked (QDML) laser is fabricated by our lab, and a scheme with 12.5 Gb/s multi-channel broadcasting transmission for free-space optical (FSO) communication is proposed based on the OFC module. The output power of the OFC is very stable, with the specially designed circuit and the flatness of the frequency comb over the span of 6 nm, which can be limited to 1.5 dB. Four channel wavelengths are chosen to demonstrate one-to-many channels for FSO communication, like optical wireless broadcast. The outdoor experiment is established to test the bit error rate (BER) and eye diagrams with 12.5 Gb/s on-off keying (OOK). The indoor experiment is used to test the highest traffic rate, which is up to 21 Gb/s for one-hop FSO communication. To the best of our knowledge, this scheme is the first to propose the realization of one-to-many broadcasting transmission for FSO communication based on the OFC module. The advantages of integration, miniaturization, channelization, low power consumption, and unlimited bandwidth of one-to-many broadcasting communication scheme, shows promising results on constructing the future space-air-ground-ocean (SAGO) FSO communication networks.

  18. Data transmission techniques for short-range optical fiber and wireless communication links

    DEFF Research Database (Denmark)

    Pham, Tien Thang

    The research work described in this thesis is devoted to experimental investigation of techniques for cost-effective high-speed optical communications supporting both wired and wireless services. The main contributions of this thesis have expanded the state-of-the-art in two main areas: high......-speed optical/wireless integration and advanced modulation formats for intensity modulation with direct detection (IM/DD) optical systems. Regarding optical/wireless integration, this thesis focuses on integration of broadband ultra-wide band (UWB) and 60-GHz band wireless systems into optical fiber access...... networks to distribute wireless services in personal area networks (PANs). Photonic technologies to generate and distribute gigabit UWB and 60-GHz-band signals are proposed and demonstrated. Two novel methods are proposed and demonstrated to optically generate Federal Communications Commission (FCC...

  19. Seamless Translation of Optical Fiber PolMux-OFDM into a 2x2 MIMO Wireless Transmission Enabled by Digital Training-Based Fiber-Wireless Channel Estimation

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Zhao, Ying; Deng, Lei

    2011-01-01

    We propose and demonstrate a 2 × 2 multiple-input multiple-output (MIMO) wireless over fiber transmission system. Seamless translation of two orthogonal frequency division multiplexing (OFDM) signals on dual optical polarization states into wireless MIMO transmission at 795.5 Mbit/s net data rate...

  20. Development of tellurium oxide and lead-bismuth oxide glasses for mid-wave infra-red transmission optics

    Science.gov (United States)

    Zhou, Beiming; Rapp, Charles F.; Driver, John K.; Myers, Michael J.; Myers, John D.; Goldstein, Jonathan; Utano, Rich; Gupta, Shantanu

    2013-03-01

    Heavy metal oxide glasses exhibiting high transmission in the Mid-Wave Infra-Red (MWIR) spectrum are often difficult to manufacture in large sizes with optimized physical and optical properties. In this work, we researched and developed improved tellurium-zinc-barium and lead-bismuth-gallium heavy metal oxide glasses for use in the manufacture of fiber optics, optical components and laser gain materials. Two glass families were investigated, one based upon tellurium and another based on lead-bismuth. Glass compositions were optimized for stability and high transmission in the MWIR. Targeted glass specifications included low hydroxyl concentration, extended MWIR transmission window, and high resistance against devitrification upon heating. Work included the processing of high purity raw materials, melting under controlled dry Redox balanced atmosphere, finning, casting and annealing. Batch melts as large as 4 kilograms were sprue cast into aluminum and stainless steel molds or temperature controlled bronze tube with mechanical bait. Small (100g) test melts were typically processed in-situ in a 5%Au°/95%Pt° crucible. Our group manufactured and evaluated over 100 different experimental heavy metal glass compositions during a two year period. A wide range of glass melting, fining, casting techniques and experimental protocols were employed. MWIR glass applications include remote sensing, directional infrared counter measures, detection of explosives and chemical warfare agents, laser detection tracking and ranging, range gated imaging and spectroscopy. Enhanced long range mid-infrared sensor performance is optimized when operating in the atmospheric windows from ~ 2.0 to 2.4μm, ~ 3.5 to 4.3μm and ~ 4.5 to 5.0μm.

  1. Industrial fabrication of an optical security device for document protection using plasmon resonant transmission through a thin corrugated metallic film embedded on a plastic foil

    Science.gov (United States)

    Sauvage-Vincent, Jean; Jourlin, Yves; Tonchev, Svetlen; Veillas, Colette; Claude, Pedri; Parriaux, Olivier

    2012-06-01

    Known since a long time in polymer banknotes and presented in the few years in paper banknotes, the principle of windowed documents has been currently extended to ID documents. We present an innovative solution which combines resonant transmission and Zero Order Device technologies and which is dedicated to improve windows in terms of the overt security level. With this R&D program, Hologram Industries targeted to obtain an overt visual security device that should be readily checked in transmission in the same manner as the established paper watermark. The proposed solution is based on the propagation of resonant modes in a thin continuous corrugated metallic layer embedded (encapsulated) between two dielectric layers of near equal refractive index. The mode of most interest is the Long Range Plasmon Mode. The coupling condition to the Long Range Mode is principally related to the corrugation, the metal layer thickness and the index of the two dielectric layers. If the condition of the mode excitation through the grating is fulfilled, a predetermined wavelength will be coupled to the Long Range Plasmon Mode. This mode will propagate at each metal/dielectric interface with a low loss and will concentrate the electric field inside the metal layer. This effect of coupling enables the transmission of a peak at this wavelength through the metallic layer. It defines the so called "extraordinary resonant transmission".

  2. Experimental demonstration of 30 Gb/s direct-detection optical OFDM transmission with blind symbol synchronisation using virtual subcarriers.

    Science.gov (United States)

    Bouziane, R; Milder, P A; Erkılınç, S; Galdino, L; Kilmurray, S; Thomsen, B C; Bayvel, P; Killey, R I

    2014-02-24

    The paper investigates the performance of a blind symbol synchronisation technique for optical OFDM systems based on virtual subcarriers. The test-bed includes a real-time 16-QAM OFDM transmitter operating at a net data rate of 30.65 Gb/s using a single OFDM band with a single FPGA-DAC subsystem and demonstrates transmission over 23.3 km SSMF with direct detection at a BER of 10(-3). By comparing the performance of the proposed synchronisation scheme with that of the Schmidl and Cox algorithm, it was found that the two approaches achieve similar performance for large numbers of averaging symbols, but the performance of the proposed scheme degrades as the number of averaging symbols is reduced. The proposed technique has lower complexity and bandwidth overhead as it does not rely on training sequences. Consequently, it is suitable for implementation in high speed optical OFDM transceivers.

  3. Four-dimensional optical multiband-OFDM for beyond 1.4 Tb/s serial optical transmission.

    Science.gov (United States)

    Djordjevic, Ivan; Batshon, Hussam G; Xu, Lei; Wang, Ting

    2011-01-17

    We propose a four-dimensional (4D) coded multiband-OFDM scheme suitable for beyond 1.4 Tb/s serial optical transport. The proposed scheme organizes the N-dimensional (ND) signal constellation points in the form of signal matrix; employs 2D-inverse FFT and 2D-FFT to perform modulation and demodulation, respectively; and exploits both orthogonal polarizations. This scheme can fully exploit advantages of OFDM to deal with chromatic dispersion, PMD and PDL effects; and multidimensional signal constellations to improve OSNR sensitivity of conventional optical OFDM. The improvement of 4D-OFDM over corresponding polarization-multiplexed QAM (with the same number of constellation points) ranges from 1.79 dB for 16 signal constellation point-four-dimensional-OFDM (16-4D-OFDM) up to 4.53 dB for 128-4D-OFDM.

  4. Nonlinearity effect of electro-optical modulator response in double spread CDMA radio-over-fiber transmissions

    Science.gov (United States)

    Huang, Jen-Fa; Yen, Chih-Ta; Li, Tzung-Yen

    2008-07-01

    This study presents a double-spread code-division multiple-access (CDMA) scheme for radio-over-fiber (RoF) transmissions. The network coder/decoders (codecs) are implemented using arrayed-waveguide grating (AWG) routers coded with maximal-length sequence ( M-sequence) codes. The effects of phase-induced intensity noise (PIIN) and multiple-access interference (MAI) on the system performance are evaluated numerically for different values of the optical modulation index (OMI) during the nonlinear electro-optical modulator (EOM) response. At low OMI optical device noise is dominant, but at high OMI nonlinear effect becomes significant. Numerical result shows that the system performance is highly sensitive to the OMI. Therefore, specifying an appropriate value of the OMI is essential in optimizing the system performance. The influence of the degree of polarization (DOP) in the system is also discussed. By employing the scrambler in front of the balanced photo-detector, the system performance can be enhanced. The high-performance, low-cost characteristics of the double-spread CDMA render the scheme an ideal solution for radio-CDMA wireless system cascaded with optical CDMA network.

  5. 26 Tbit s-1 line-rate super-channel transmission utilizing all-optical fast Fourier transform processing

    Science.gov (United States)

    Hillerkuss, D.; Schmogrow, R.; Schellinger, T.; Jordan, M.; Winter, M.; Huber, G.; Vallaitis, T.; Bonk, R.; Kleinow, P.; Frey, F.; Roeger, M.; Koenig, S.; Ludwig, A.; Marculescu, A.; Li, J.; Hoh, M.; Dreschmann, M.; Meyer, J.; Ben Ezra, S.; Narkiss, N.; Nebendahl, B.; Parmigiani, F.; Petropoulos, P.; Resan, B.; Oehler, A.; Weingarten, K.; Ellermeyer, T.; Lutz, J.; Moeller, M.; Huebner, M.; Becker, J.; Koos, C.; Freude, W.; Leuthold, J.

    2011-06-01

    Optical transmission systems with terabit per second (Tbit s-1) single-channel line rates no longer seem to be too far-fetched. New services such as cloud computing, three-dimensional high-definition television and virtual-reality applications require unprecedented optical channel bandwidths. These high-capacity optical channels, however, are fed from lower-bitrate signals. The question then is whether the lower-bitrate tributary information can viably, energy-efficiently and effortlessly be encoded to and extracted from terabit per second data streams. We demonstrate an optical fast Fourier transform scheme that provides the necessary computing power to encode lower-bitrate tributaries into 10.8 and 26.0 Tbit s-1 line-rate orthogonal frequency-division multiplexing (OFDM) data streams and to decode them from fibre-transmitted OFDM data streams. Experiments show the feasibility and ease of handling terabit per second data with low energy consumption. To the best of our knowledge, this is the largest line rate ever encoded onto a single light source.

  6. Counteracting 16-QAM Optical Fiber Transmission Impairments With Iterative Turbo Equalization

    DEFF Research Database (Denmark)

    Arlunno, Valeria; Caballero Jambrina, Antonio; Borkowski, Robert

    2013-01-01

    A turbo equalization (TE) scheme based on convolutional code and normalized least mean square equalizer for coherent optical communication links is proposed and experimentally demonstrated. The proposed iterative TE technique is proved effective for counteracting polarization-division-multiplexin......A turbo equalization (TE) scheme based on convolutional code and normalized least mean square equalizer for coherent optical communication links is proposed and experimentally demonstrated. The proposed iterative TE technique is proved effective for counteracting polarization...

  7. Construction tolerances for low loss, dielectric coated, metallic waveguide for transmission optical radiation

    International Nuclear Information System (INIS)

    Sandweiss, J.

    1984-08-01

    The transmission of radiation, in a specific mode of interest for the IFELA, past a symmetric step in dielectric coating thickness has been calculated. The result shows that the transmission loss depends on the quantity (s/D) 2 and vanishes to first order in the ratio of the step s to the guide aperture D. With the reasonable assumption that this feature holds for all forms of surface imperfections, the attenuation length due to imperfections has been estimated. It is found that rms surface roughness of approx. 0.1 μ m leads to attenuation lengths of 25 km or greater

  8. Taking the Extra out of the Extraordinary

    DEFF Research Database (Denmark)

    Jerslev, Anne; Mortensen, Mette

    2014-01-01

    people engaged in insignificant everyday activities hold by far the largest share of today’s insatiable digital, globalized and commercialized market for news pictures of celebrities off-duty. Re-examining the well-known theorization of the tension between the ordinary and extraordinary in celebrity......Paparazzi photography presently constitutes the largest genre of visual celebrity news on the internet along with red carpet photography. With the emergence of digital media, this genre has moved towards the centre of mainstream news and entertainment culture, and the content has undergone...... culture studies, this article thus investigates the following research question: How is the ordinary represented in paparazzi photographs as a genre of visual celebrity news in the current, digital media landscape?...

  9. Nonlinear extraordinary wave in dense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Krasovitskiy, V. B., E-mail: krasovit@mail.ru [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Turikov, V. A. [Russian University of Peoples’ Friendship (Russian Federation)

    2013-10-15

    Conditions for the propagation of a slow extraordinary wave in dense magnetized plasma are found. A solution to the set of relativistic hydrodynamic equations and Maxwell’s equations under the plasma resonance conditions, when the phase velocity of the nonlinear wave is equal to the speed of light, is obtained. The deviation of the wave frequency from the resonance frequency is accompanied by nonlinear longitudinal-transverse oscillations. It is shown that, in this case, the solution to the set of self-consistent equations obtained by averaging the initial equations over the period of high-frequency oscillations has the form of an envelope soliton. The possibility of excitation of a nonlinear wave in plasma by an external electromagnetic pulse is confirmed by numerical simulations.

  10. Modeling the planar configuration of extraordinary magnetoresistance

    International Nuclear Information System (INIS)

    El-Ahmar, S; Pozniak, A A

    2015-01-01

    Recently the planar version of the extraordinary magnetoresistance (EMR) magnetic field sensor has been constructed and verified in practice. Planar configuration of the EMR device gives many technological advantages, it is simpler than the classic and allows one to build the sensor using electric materials of the new type (such as graphene or topological insulators) much easier. In this work the planar configuration of the EMR sensor is investigated by performing computational simulations using the finite element method (FEM). The computational comparison of the planar and classic configurations of EMR is presented using three-dimensional models. Various variants of the geometry of EMR sensor components are pondered and compared in the planar and classic version. Size of the metal overlap is considered for sensor optimization as well as various semiconductor-metal contact resistance dependences of the EMR signal. Based on computational simulations, a method for optimal placement of electric terminals in a planar EMR device is proposed. (paper)

  11. The making of extraordinary psychological phenomena.

    Science.gov (United States)

    Lamont, Peter

    2012-01-01

    This article considers the extraordinary phenomena that have been central to unorthodox areas of psychological knowledge. It shows how even the agreed facts relating to mesmerism, spiritualism, psychical research, and parapsychology have been framed as evidence both for and against the reality of the phenomena. It argues that these disputes can be seen as a means through which beliefs have been formulated and maintained in the face of potentially challenging evidence. It also shows how these disputes appealed to different forms of expertise, and that both sides appealed to belief in various ways as part of the ongoing dispute about both the facts and expertise. Finally, it shows how, when a formal Psychology of paranormal belief emerged in the twentieth century, it took two different forms, each reflecting one side of the ongoing dispute about the reality of the phenomena. © 2012 Wiley Periodicals, Inc.

  12. A novel construction scheme of QC-LDPC codes based on the RU algorithm for optical transmission systems

    Science.gov (United States)

    Yuan, Jian-guo; Liang, Meng-qi; Wang, Yong; Lin, Jin-zhao; Pang, Yu

    2016-03-01

    A novel lower-complexity construction scheme of quasi-cyclic low-density parity-check (QC-LDPC) codes for optical transmission systems is proposed based on the structure of the parity-check matrix for the Richardson-Urbanke (RU) algorithm. Furthermore, a novel irregular QC-LDPC(4 288, 4 020) code with high code-rate of 0.937 is constructed by this novel construction scheme. The simulation analyses show that the net coding gain ( NCG) of the novel irregular QC-LDPC(4 288,4 020) code is respectively 2.08 dB, 1.25 dB and 0.29 dB more than those of the classic RS(255, 239) code, the LDPC(32 640, 30 592) code and the irregular QC-LDPC(3 843, 3 603) code at the bit error rate ( BER) of 10-6. The irregular QC-LDPC(4 288, 4 020) code has the lower encoding/decoding complexity compared with the LDPC(32 640, 30 592) code and the irregular QC-LDPC(3 843, 3 603) code. The proposed novel QC-LDPC(4 288, 4 020) code can be more suitable for the increasing development requirements of high-speed optical transmission systems.

  13. The infrared transmission through gold films on ordered two-dimensional non-close-packed colloidal crystals

    International Nuclear Information System (INIS)

    Ju Jing; Zhou Yuqin; Dong Gangqiang

    2014-01-01

    We studied the infrared transmission properties of gold films on ordered two-dimensional non-close-packed polystyrene (PS) colloidal crystal. The gold films consist of gold half-shells on the PS spheres and gold film with 2D arrays of holes on the glass substrate. An extraordinary optical transmission phenomenon could be found in such a structure. Simulations with the finite-difference time-domain method were also employed to get the transmission spectra and electric field distribution. The transmission response of the samples can be adjusted by controlling the thickness of the gold films. Angle-resolved measurements were performed using polarized light to obtain more information about the surface plasmon polariton resonances of the gold films. As the angle changes, the transmission spectra change a lot. The transmission spectra of p-polarized light have quite different properties compared to those of s-polarized light. (semiconductor physics)

  14. Modelling optical fibers acquisition and transmission systems for their use in nuclear environments

    International Nuclear Information System (INIS)

    Van-Uffelen, Marco

    2001-01-01

    In order to introduce connections based on optical fibres in the field of civil nuclear activities, it is important to have a good knowledge of their behaviour under irradiation. The objective of this research thesis is thus to develop a tool to predict the lifetime of such an optical connection which would allow a predictive maintenance. The adopted methodology relies on a modular approach and consists in the characterization of the behaviour of individual components under test conditions which are representative of addressed applications. Transfer functions are then chained to obtain the connection predictive model. Various components have been studied: mono- and multi-mode optical fibres, light-emitting diodes, vertical-cavity surface-emitting laser diodes (VCSEL), as well as Si and InGaAs sensors. These components have been submitted to a range of dose rates and cumulated dose under temperatures reaching 85 C. Based on on-line measurements, a pragmatic approach has been assessed to predict the evolution of optical losses induced in optical fibres during several months. The difference between measurements and predictions ranges between 10 and 20 per cent depending on the fibre type and on the wavelength. VCSELs display a high tolerance to gamma radiation and a steady operation at high temperatures, whereas sensors appear to be the weakest link [fr

  15. Fiber Optic Cables for Transmission of High-Power Laser Pulses in Spaceflight Applications

    Science.gov (United States)

    Thomes, W. J., Jr.; Ott, M. N.; Chuska, R. F.; Switzer, R. C.; Blair, D. E.

    2010-01-01

    Lasers with high peak power pulses are commonly used in spaceflight missions for a wide range of applications, from LIDAR systems to optical communications. Due to the high optical power needed, the laser has to be located on the exterior of the satellite or coupled through a series of free space optics. This presents challenges for thermal management, radiation resistance, and mechanical design. Future applications will require multiple lasers located close together, which further complicates the design. Coupling the laser energy into a fiber optic cable allows the laser to be relocated to a more favorable position on the spacecraft. Typical fiber optic termination procedures are not sufficient for injection of these high-power laser pulses without catastrophic damage to the fiber endface. In the current study, we will review the causes of fiber damage during high-power injection and discuss our new manufacturing procedures that overcome these issues to permit fiber use with high reliability in these applications. We will also discuss the proper methods for launching the laser pulses into the fiber to avoid damage and how this is being implemented for current spaceflight missions.

  16. Fiber optic cables for transmission of high-power laser pulses in spaceflight applications

    Science.gov (United States)

    Thomes, W. J.; Ott, M. N.; Chuska, R. F.; Switzer, R. C.; Blair, D. E.

    2017-11-01

    Lasers with high peak power pulses are commonly used in spaceflight missions for a wide range of applications, from LIDAR systems to optical communications. Due to the high optical power needed, the laser has to be located on the exterior of the satellite or coupled through a series of free space optics. This presents challenges for thermal management, radiation resistance, and mechanical design. Future applications will require multiple lasers located close together, which further complicates the design. Coupling the laser energy into a fiber optic cable allows the laser to be relocated to a more favorable position on the spacecraft. Typical fiber optic termination procedures are not sufficient for injection of these high-power laser pulses without catastrophic damage to the fiber endface. In the current study, we will review the causes of fiber damage during high-power injection and discuss our new manufacturing procedures that overcome these issues to permit fiber use with high reliability in these applications. We will also discuss the proper methods for launching the laser pulses into the fiber to avoid damage and how this is being implemented for current spaceflight missions.

  17. Linear and Nonlinear Impairment Compensation in Coherent Optical Transmission with Digital Signal Processing

    DEFF Research Database (Denmark)

    Porto da Silva, Edson

    Digital signal processing (DSP) has become one of the main enabling technologies for the physical layer of coherent optical communication networks. The DSP subsystems are used to implement several functionalities in the digital domain, from synchronization to channel equalization. Flexibility...... nonlinearity compensation, (II) spectral shaping, and (III) adaptive equalization. For (I), original contributions are presented to the study of the nonlinearity compensation (NLC) with digital backpropagation (DBP). Numerical and experimental performance investigations are shown for different application...... scenarios. Concerning (II), it is demonstrated how optical and electrical (digital) pulse shaping can be allied to improve the spectral confinement of a particular class of optical time-division multiplexing (OTDM) signals that can be used as a building block for fast signaling single-carrier transceivers...

  18. Towards attosecond synchronization of remote mode-locked lasers using stabilized transmission of optical comb frequencies

    Science.gov (United States)

    Wilcox, R. B.; Byrd, J. M.; Doolittle, L. R.; Holzwarth, R.; Huang, G.

    2011-09-01

    We propose a method of synchronizing mode-locked lasers separated by hundreds of meters with the possibility of achieving sub-fs performance by locking the phases of corresponding lines in the optical comb spectrum. The optical phase from one comb line is transmitted to the remote laser over an interferometrically stabilized link by locking a single frequency laser to a comb line with high phase stability. We describe how these elements are integrated into a complete system and estimate the potential performance.

  19. Modeling optical transmissivity of graphene grate in on-chip silicon photonic device

    Science.gov (United States)

    Amiri, Iraj S.; Ariannejad, M. M.; Jalil, M. A.; Ali, J.; Yupapin, P.

    2018-06-01

    A three-dimensional (3-D) finite-difference-time-domain (FDTD) analysis was used to simulate a silicon photonic waveguide. We have calculated power and transmission of the graphene used as single or multilayers to study the light transmission behavior. A new technique has been developed to define the straight silicon waveguide integrated with grate graphene layer. The waveguide has a variable grate spacing to be filled by the graphene layer. The number of graphene atomic layers varies between 100 and 1000 (or 380 nm and 3800 nm), the transmitted power obtained varies as ∼30% and ∼80%. The ∼99%, blocking of the light was occurred in 10,000 (or 38,000 nm) atomic layers of the graphene grate.

  20. Full-color, large area, transmissive holograms enabled by multi-level diffractive optics.

    Science.gov (United States)

    Mohammad, Nabil; Meem, Monjurul; Wan, Xiaowen; Menon, Rajesh

    2017-07-19

    We show that multi-level diffractive microstructures can enable broadband, on-axis transmissive holograms that can project complex full-color images, which are invariant to viewing angle. Compared to alternatives like metaholograms, diffractive holograms utilize much larger minimum features (>10 µm), much smaller aspect ratios (30 mm ×30 mm). We designed, fabricated and characterized holograms that encode various full-color images. Our devices demonstrate absolute transmission efficiencies of >86% across the visible spectrum from 405 nm to 633 nm (peak value of about 92%), and excellent color fidelity. Furthermore, these devices do not exhibit polarization dependence. Finally, we emphasize that our devices exhibit negligible absorption and are phase-only holograms with high diffraction efficiency.

  1. Dynamic optical fiber delivery of Ka-band packet transmissions for wireless access networks

    DEFF Research Database (Denmark)

    Rodríguez Páez, Juan Sebastián; Madsen, Peter; Tafur Monroy, Idelfonso

    2017-01-01

    A Reconfigurable Radio Access Unit is presented and experimentally demonstrated. In the unit, an optical switching system is set to dynamically deliver different packets to different points in the network. The packets are transmitted wirelesslty on the Ka-band (26–40 GHz), achieving BER values...

  2. Low-crosstalk full-duplex all-optical indoor wireless transmission with carrier recovery

    NARCIS (Netherlands)

    Oh, C.W.; Cao, Z.; Mekonnen, K.A.; Tangdiongga, E.; Koonen, A.M.J.

    2017-01-01

    We propose and demonstrate a novel bi-directional free-space (FS) optical wireless communication system for indoor wireless networks. A 2-D infrared beam-steered system supporting full-duplex communication of at least 10 Gb/s capacity per wireless terminal with simple NRZ-OOK modulation format is

  3. Quantum coherent optical phase modulation in an ultrafast transmission electron microscope.

    Science.gov (United States)

    Feist, Armin; Echternkamp, Katharina E; Schauss, Jakob; Yalunin, Sergey V; Schäfer, Sascha; Ropers, Claus

    2015-05-14

    Coherent manipulation of quantum systems with light is expected to be a cornerstone of future information and communication technology, including quantum computation and cryptography. The transfer of an optical phase onto a quantum wavefunction is a defining aspect of coherent interactions and forms the basis of quantum state preparation, synchronization and metrology. Light-phase-modulated electron states near atoms and molecules are essential for the techniques of attosecond science, including the generation of extreme-ultraviolet pulses and orbital tomography. In contrast, the quantum-coherent phase-modulation of energetic free-electron beams has not been demonstrated, although it promises direct access to ultrafast imaging and spectroscopy with tailored electron pulses on the attosecond scale. Here we demonstrate the coherent quantum state manipulation of free-electron populations in an electron microscope beam. We employ the interaction of ultrashort electron pulses with optical near-fields to induce Rabi oscillations in the populations of electron momentum states, observed as a function of the optical driving field. Excellent agreement with the scaling of an equal-Rabi multilevel quantum ladder is obtained, representing the observation of a light-driven 'quantum walk' coherently reshaping electron density in momentum space. We note that, after the interaction, the optically generated superposition of momentum states evolves into a train of attosecond electron pulses. Our results reveal the potential of quantum control for the precision structuring of electron densities, with possible applications ranging from ultrafast electron spectroscopy and microscopy to accelerator science and free-electron lasers.

  4. Frequency Domain Training-Aided Channel Estimation and Equalization in Time-Varying Optical Transmission Systems

    DEFF Research Database (Denmark)

    Pittalà, Fabio; Msallem, Majdi; Hauske, Fabian N.

    2012-01-01

    We propose a non-weighted feed-forward equalization method with filter update by averaging channel estimations based on short CAZAC sequences. Three averaging methods are presented and tested by simulations in a time-varying 2×2 MIMO optical system....

  5. InP microdisks for optical signal processing and data transmission

    NARCIS (Netherlands)

    Hofrichter, J.

    2013-01-01

    The performance increase in telecommunication and computing systems demands an ever increasing input-output (IO) bandwidth and IO density, which can be met by integrated photonics. Using photonic integration, much higher densities of optical components can be achieved allowing for short-range

  6. Transmission enhancement by deployment of interferometric wavelength converters within all-optical cross connects

    DEFF Research Database (Denmark)

    Poulsen, Henrik Nørskov; Mikkelsen, Benny; Stubkjær, Kristian

    1997-01-01

    Wavelength-division multiplexing (WDM) networks are expected to utilize all-optical cross connects (OXCN) for signal routing. Because a signal path is likely to contain a number of OXCNs, their cascadability is essential. Furthermore, because wavelength converters in the OXCNs improve traffic...

  7. Nonlinear Optics in Spatially Negatively Dispersive Metamaterials: Extraordinary and Counterintuitive

    Science.gov (United States)

    2014-11-17

    aerogel disk samples...They  are  designed  to  cover  most  of  the   aircraft  surface  to  sense  and  manipulate   the  electromagnetic...illness.  In  defense,  the  surface  of   ships  and   aircrafts  is  painted  with  electromagnetic  absorbing

  8. 22 CFR 41.55 - Aliens with extraordinary ability.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Aliens with extraordinary ability. 41.55... IMMIGRATION AND NATIONALITY ACT, AS AMENDED Business and Media Visas § 41.55 Aliens with extraordinary ability. (a) Requirements for O classification. An alien shall be classifiable under the provisions of INA 101...

  9. Nonlinear propagation of the extraordinary mode in a hot magnetoplasma

    International Nuclear Information System (INIS)

    Khiet, Tu; Furutani, Y.; Ichikawa, Y.H.

    1978-07-01

    Kinetic theory for a nonlinear propagation of quasi-monochromatic extraordinary waves is presented. It reveals that propagation of an envelope of the extraordinary carriers is described by the nonlinear Schroedinger equation. In a cold plasma limit, a detailed analysis is carried out on a behaviour of the envelope of the upper- and the lower-hybrid waves at respective resonant frequency ranges. (author)

  10. 7 CFR 1773.41 - Extraordinary retirement losses.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Extraordinary retirement losses. 1773.41 Section 1773... Documentation § 1773.41 Extraordinary retirement losses. The CPA's workpapers must contain an analysis of retirement losses, including any required approval by a regulatory commission with jurisdiction in the matter...

  11. Interference-Assisted Techniques for Transmission and Multiple Access in Optical Communications

    Science.gov (United States)

    Guan, Xun

    Optical communications can be in wired or wireless form. Fiber optics communication (FOC) connects transmitters and receivers with optical fiber. Benefiting from its high bandwidth, low cost per volume and stability, it gains a significant market share in long-haul networks, access networks and data centers. Meanwhile, optical wireless communication (OWC) is also emerging as a crucial player in the communication market. In OWC, free-space optical communication (FSO) and visible light communication (VLC) are being studied and commercially deployed extensively. Interference is a common phenomenon in multi-user communication systems. In both FOC and OWC, interference has long been treated as a detrimental effect. However, it could also be beneficial to system applications. The effort of harnessing interference has spurred numerous innovations. Interesting examples are physical-layer network coding (PNC) and non-orthogonal multiple access (NOMA). The first part of this thesis in on the topic of PNC. PNC was firstly proposed in wireless communication to improve the throughput of a two-way relay network (TWRN). As a variation of network coding (NC), PNC turns the common channel interference (CCI) as a natural network coding operation. In this thesis, PNC is introduced into optical communication. Three schemes are proposed in different scenarios. Firstly, PNC is applied to a coherent optical orthogonal frequency division multiplexing (CO-OFDM) system so as to improve the throughput of the multicast network. The optical signal to noise ratio (OSNR) penalty is quite low. Secondly, we investigate the application of PNC in an OFDM passive optical network (OFDM-PON) supporting heterogeneous services. It is found that only minor receiver power penalties are observed to realize PNC-based virtual private networks (VPN), both in the wired service part and the wireless service part in an OFDM-PON with heterogeneous services. Thirdly, we innovate relay-based visible light

  12. Extraordinary Rendition and U.S. Counterterrorism Policy

    Directory of Open Access Journals (Sweden)

    Mark J. Murray

    2011-01-01

    Full Text Available This article examines the United States Government policy of extraordinary rendition as a response to terrorism. The paper provides a working definition of the term, outlines why it has become controversial, and uses case studies to examine success and failures of extraordinary rendition in practice. The paper concludes with lessons learned—more specifically, policy amendments—that are necessary to keep extraordinary rendition as a viable tool for the Obama Administration and mitigate political fallout against the United States from both its allies and enemies. This paper argues that extraordinary rendition provides flexibility to policymakers to detain terrorists in cases where an attack may be forthcoming and when other approved legal processes are slow to react. Therefore, instead of ending extraordinary renditions altogether, the United States should reevaluate how it implements the policy on a tactical, operational, and strategic level and amend it based on the recommendations put forward in this article.

  13. Optical fiber link for transmission of 1-nJ femtosecond laser pulses at 1550 nm

    DEFF Research Database (Denmark)

    Eichhorn, Finn; Olsson, Rasmus Kjelsmark; Buron, Jonas Christian Due

    2010-01-01

    We report on numerical and experimental characterization of the performance of a fiber link optimized for the delivery of sub-100-fs laser pulses at 1550 nm over several meters of fiber. We investigate the power handling capacity of the link, and demonstrate all-fiber delivery of 1-nJ pulses over...... a distance of 5.3 m. The fiber link consists of dispersion-compensating fiber (DCF) and standard single-mode fiber. The optical pulses at different positions in the fiber link are measured using frequency-resolved optical gating (FROG). The results are compared with numerical simulations of the pulse...... propagation based on the generalized nonlinear Schrödinger equation. The high input power capacity of the fiber link allows the splitting and distribution of femtosecond pulses to an array of fibers with applications in multi-channel fiber-coupled terahertz time-domain spectroscopy and imaging systems. We...

  14. Adaptive elimination of optical fiber transmission noise in fiber ocean bottom seismic system

    Science.gov (United States)

    Zhong, Qiuwen; Hu, Zhengliang; Cao, Chunyan; Dong, Hongsheng

    2017-10-01

    In this paper, a pressure and acceleration insensitive reference Interferometer is used to obtain laser and public noise introduced by transmission fiber and laser. By using direct subtraction and adaptive filtering, this paper attempts to eliminate and estimation the transmission noise of sensing probe. This paper compares the noise suppression effect of four methods, including the direct subtraction (DS), the least mean square error adaptive elimination (LMS), the normalized least mean square error adaptive elimination (NLMS) and the least square (RLS) adaptive filtering. The experimental results show that the noise reduction effect of RLS and NLMS are almost the same, better than LMS and DS, which can reach 8dB (@100Hz). But considering the workload, RLS is not conducive to the real-time operating system. When it comes to the same treatment effect, the practicability of NLMS is higher than RLS. The noise reduction effect of LMS is slightly worse than that of RLS and NLMS, about 6dB (@100Hz), but its computational complexity is small, which is beneficial to the real time system implementation. It can also be seen that the DS method has the least amount of computational complexity, but the noise suppression effect is worse than that of the adaptive filter due to the difference of the noise amplitude between the RI and the SI, only 4dB (@100Hz) can be reached. The adaptive filter can basically eliminate the influence of the transmission noise, and the simulation signal of the sensor is kept intact.

  15. Channel modelling for free-space optical inter-HAP links using adaptive ARQ transmission

    Science.gov (United States)

    Parthasarathy, S.; Giggenbach, D.; Kirstädter, A.

    2014-10-01

    Free-space optical (FSO) communication systems have seen significant developments in recent years due to growing need for very high data rates and tap-proof communication. The operation of an FSO link is suited to diverse variety of applications such as satellites, High Altitude Platforms (HAPs), Unmanned Aerial Vehicles (UAVs), aircrafts, ground stations and other areas involving both civil and military situations. FSO communication systems face challenges due to different effects of the atmospheric channel. FSO channel primarily suffers from scintillation effects due to Index of Refraction Turbulence (IRT). In addition, acquisition and pointing becomes more difficult because of the high directivity of the transmitted beam: Miss-pointing of the transmitted beam and tracking errors at the receiver generate additional fading of the optical signal. High Altitude Platforms (HAPs) are quasi-stationary vehicles operating in the stratosphere. The slowly varying but precisely determined time-of-flight of the Inter-HAP channel adds to its characteristics. To propose a suitable ARQ scheme, proper theoretical understanding of the optical atmospheric propagation and modeling of a specific scenario FSO channel is required. In this paper, a bi-directional symmetrical Inter-HAP link has been selected and modeled. The Inter-HAP channel model is then investigated via simulations in terms of optical scintillation induced by IRT and in presence of pointing error. The performance characteristic of the model is then quantified in terms of fading statistics from which the Packet Error Probability (PEP) is calculated. Based on the PEP characteristics, we propose suitable ARQ schemes.

  16. Fiber optic cryogenic sensors for superconducting magnets and superconducting power transmission lines at CERN

    Science.gov (United States)

    Chiuchiolo, A.; Bajko, M.; Perez, J. C.; Bajas, H.; Consales, M.; Giordano, M.; Breglio, G.; Palmieri, L.; Cusano, A.

    2014-08-01

    The design, fabrication and tests of a new generation of superconducting magnets for the upgrade of the LHC require the support of an adequate, robust and reliable sensing technology. The use of Fiber Optic Sensors is becoming particularly challenging for applications in extreme harsh environments such as ultra-low temperatures, high electromagnetic fields and strong mechanical stresses offering perspectives for the development of technological innovations in several applied disciplines.

  17. Optic fibber data acquisition and transmission system dedicated to a neutron generator

    International Nuclear Information System (INIS)

    Ledo Pereda, Luis Miguel; Vergara Limon, Sergio; Arteche Diaz, Raul

    2009-01-01

    Hereby, are presented the design, construction and application of a virtual data acquisition system based on the usage of microcontrollers, optic fibber, and PC. System is aimed to the reestablishment of the communication between the basic modules of a Neutron Generator. The work shows, how the original interface design is upgraded by the automation of the data acquisition, on the Neutron Generator exploitation parameters. The PC usage is being introduced in the Neutron Generator and the precedent is established for further subsystem

  18. GJ 1214: Rotation period, starspots, and uncertainty on the optical slope of the transmission spectrum

    Science.gov (United States)

    Mallonn, M.; Herrero, E.; Juvan, I. G.; Essen, C. von; Rosich, A.; Ribas, I.; Granzer, T.; Alexoudi, X.; Strassmeier, K. G.

    2018-06-01

    Aims: Brightness inhomogeneities in the stellar photosphere (dark spots or bright regions) affect the measurements of the planetary transmission spectrum. To investigate the star spots of the M dwarf GJ 1214, we conducted a multicolor photometric monitoring from 2012 to 2016. Methods: The time-series photometry was analyzed with the light curve inversion tool StarSim. Using the derived stellar surface properties from the light curve inversion, we modeled the impact of the star spots when unocculted by the transiting planet. We compared the photometric variability of GJ 1214 to published results of mid- to late M dwarfs from the MEarth sample. Results: The measured variability shows a periodicity of 125 ± 5 days, which we interpret as the signature of the stellar rotation period. This value overrules previous suggestions of a significantly shorter stellar rotation period. A light curve inversion of the monitoring data yields an estimation of the flux dimming of a permanent spot filling factor not contributing to the photometric variability, a temperature contrast of the spots of 370 K and persistent active longitudes. The derived surface maps over all five seasons were used to estimate the influence of the star spots on the transmission spectrum of the planet from 400 to 2000 nm. The monitoring data presented here do not support a recent interpretation of a measured transmission spectrum of GJ 1214b as to be caused by bright regions in the stellar photosphere. Instead, we list arguments as to why the effect of dark spots likely dominated over bright regions in the period of our monitoring. Furthermore, our photometry proves an increase in variability over at least four years, indicative for a cyclic activity behavior. The age of GJ 1214 is likely between 6 and 10 Gyr. Conclusions: The long-term photometry allows for a correction of unocculted spots. For an active star such as GJ 1214, there remains a degeneracy between occulted spots and the transit parameters used

  19. UHD Video Transmission over Bi-Directional Underwater Wireless Optical Communication

    KAUST Repository

    Al-Halafi, Abdullah; Shihada, Basem

    2018-01-01

    In this paper, we experimentally demonstrate for the first time a bi-directional underwater wireless optical communication system that is capable of transmitting an ultra high definition real-time video using a downlink channel while simultaneously receiving the feedback messages on the uplink channel. The links extend up to 4.5 m using QPSK, 16-QAM and 64-QAM modulations. The system is built using software defined platforms connected to TO-9 packaged pigtailed 520 nm directly modulated green laser diode (LD) with 1.2 GHz bandwidth as the optical transmitter for video streaming on the downlink, and an avalanche photodiode (APD) module as the downlink receiver. The uplink channel is connected to another pigtailed 450 nm directly modulated blue LD with 1.2 GHz bandwidth as the optical uplink transmitter for the feedback channel, and to a second APD as the uplink receiver. We perform laboratory experiments on different water types. The measured throughput is 15 Mbps for QPSK, and 30 Mbps for both 16-QAM and 64-QAM. We evaluate the quality of the received live video streams using Peak Signal-to-Noise Ratio and achieve values up to 16 dB for 64-QAM when streaming UHD video in harbor II water and 22 dB in clear ocean.

  20. Performance evaluation of optical channel transmission between UAVs and Ground Stations

    Directory of Open Access Journals (Sweden)

    Hatziefremidis Antonis

    2016-01-01

    Full Text Available Free space optical (FSO communications links is a promising solution for the provision of high data rate point to point communications. In particular deploying FSO technology for mobile links between Unmanned Aerial Vehicles (UAVs and fixed Ground Stations (GS introduces several interesting challenges. In this paper, we investigate the ability of a mobile FSO system to operate in different atmospheric conditions. Specifically, we characterize the quality of the optical channel with a proper model in terms of Bit Error Rate (BER and average Signal to Noise Ratio (SNR and we report a detailed optical amplification model able to support a constant Quality of Service for different distances from 1 km up to 35 km at 10 Gbps with 1550 nm wavelength. An extensive comparative analysis among different FSO configurations links considering the altitude of the UAV, the wavelength and the atmospheric conditions is provided. The results show that there is degradation at the BER over a slanted path compared to a horizontal path at the same conditions.

  1. UHD Video Transmission over Bi-Directional Underwater Wireless Optical Communication

    KAUST Repository

    Al-Halafi, Abdullah

    2018-04-02

    In this paper, we experimentally demonstrate for the first time a bi-directional underwater wireless optical communication system that is capable of transmitting an ultra high definition real-time video using a downlink channel while simultaneously receiving the feedback messages on the uplink channel. The links extend up to 4.5 m using QPSK, 16-QAM and 64-QAM modulations. The system is built using software defined platforms connected to TO-9 packaged pigtailed 520 nm directly modulated green laser diode (LD) with 1.2 GHz bandwidth as the optical transmitter for video streaming on the downlink, and an avalanche photodiode (APD) module as the downlink receiver. The uplink channel is connected to another pigtailed 450 nm directly modulated blue LD with 1.2 GHz bandwidth as the optical uplink transmitter for the feedback channel, and to a second APD as the uplink receiver. We perform laboratory experiments on different water types. The measured throughput is 15 Mbps for QPSK, and 30 Mbps for both 16-QAM and 64-QAM. We evaluate the quality of the received live video streams using Peak Signal-to-Noise Ratio and achieve values up to 16 dB for 64-QAM when streaming UHD video in harbor II water and 22 dB in clear ocean.

  2. Realization of OSW/AWG-based bipolar wavelength time optical CDMA for wired wireless transmissions

    Science.gov (United States)

    Yen, Chih-Ta; Huang, Jen-Fa

    2009-01-01

    This study proposes a novel radio-over-fiber (RoF) system using two-dimensional (2-D) optical code-division multiple-access (OCDMA) scheme using pseudorandom (PN) codes for the time-spreading and wavelength-hopping ( t-spreading/ λ-hopping) codes. The 2-D system is implemented using optical switches (OSWs) and arrayed-waveguide grating (AWG) routers. By constructing 2-D codes using bipolar PN codes rather than unipolar codes provides a significant increase in the maximum permissible number of active radio base stations (RBSs). In general, the phase-induced intensity noise (PIIN) generated at high optical intensities significantly degrades the performance of a conventional multi-wavelength scheme. However, the OSW-based time-spreading method employed in the current 2-D OCDMA scheme effectively suppresses the PIIN effect. Additionally, multiple-access interference (MAI) is suppressed by the use of a wavelength/time balanced detector structure in the network receivers. The numerical evaluation results demonstrate that under PIIN- and MAI-limited conditions, the proposed system outperforms a conventional multi-wavelength OCDMA scheme by using the spectral spreading scheme to suppress beating noise. Especially, the t-spreading encoder/decoder (codec) groups share the same wavelength codec and the overall complexity is reduced and system network becomes more compact.

  3. Engineering surface plasmon based fiber-optic sensors

    International Nuclear Information System (INIS)

    Dhawan, Anuj; Muth, John F.

    2008-01-01

    Ordered arrays of nanoholes with subwavelength diameters, and submicron array periodicity were fabricated on the tips of gold-coated optical fibers using focused ion beam (FIB) milling. This provided a convenient platform for evaluating extraordinary transmission of light through subwavelength apertures and allowed the implementation of nanostructures for surface plasmon engineered sensors. The fabrication procedure was straightforward and implemented on single mode and multimode optical fibers as well as etched and tapered fiber tips. Control of the periodicity and spacing of the nanoholes allowed the wavelength of operation to be tailored. Large changes in optical transmission were observed at the designed wavelengths, depending on the surrounding refractive index, allowing the devices to be used as fiber-optic sensors

  4. Engineering surface plasmon based fiber-optic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Dhawan, Anuj [Department of Electrical and Computer Engineering, NC State University, Raleigh, NC 27606 (United States); Muth, John F. [Department of Electrical and Computer Engineering, NC State University, Raleigh, NC 27606 (United States)], E-mail: muth@unity.ncsu.edu

    2008-04-15

    Ordered arrays of nanoholes with subwavelength diameters, and submicron array periodicity were fabricated on the tips of gold-coated optical fibers using focused ion beam (FIB) milling. This provided a convenient platform for evaluating extraordinary transmission of light through subwavelength apertures and allowed the implementation of nanostructures for surface plasmon engineered sensors. The fabrication procedure was straightforward and implemented on single mode and multimode optical fibers as well as etched and tapered fiber tips. Control of the periodicity and spacing of the nanoholes allowed the wavelength of operation to be tailored. Large changes in optical transmission were observed at the designed wavelengths, depending on the surrounding refractive index, allowing the devices to be used as fiber-optic sensors.

  5. Extraordinary Matter: Visualizing Space Plasmas and Particles

    Science.gov (United States)

    Barbier, S. B.; Bartolone, L.; Christian, E.; Thieman, J.; Eastman, T.; Lewis, E.

    2011-09-01

    Atoms and sub-atomic particles play a crucial role in the dynamics of our universe, but these particles and the space plasmas comprised of them are often overlooked in popular scientific and educational resources. Although the concepts are pertinent to a wide range of topics, even the most basic particle and plasma physics principles are generally unfamiliar to non-scientists. Educators and public communicators need assistance in explaining these concepts that cannot be easily demonstrated in the everyday world. Active visuals are a highly effective aid to understanding, but resources of this type are currently few in number and difficult to find, and most do not provide suitable context for audience comprehension. To address this need, our team is developing an online multimedia reference library of animations, visualizations, interactivities, and videos resources - Extraordinary Matter: Visualizing Space Plasmas and Particles. The site targets grades 9-14 and the equivalent in informal education and public outreach. Each ready-to-use product will be accompanied by a supporting explanation at a reading level matching the educational level of the concept. It will also have information on relevant science, technology, engineering, and mathematics (STEM) educational standards, activities, lesson plans, related products, links, and suggested uses. These products are intended to stand alone, making them adaptable to the widest range of uses, including scientist presentations, museum displays, educational websites and CDs, teacher professional development, and classroom use. This project is funded by a NASA Education and Public Outreach in Earth and Space Science (EPOESS) grant.

  6. A transmission line model for propagation in elliptical core optical fibers

    Science.gov (United States)

    Georgantzos, E.; Papageorgiou, C.; Boucouvalas, A. C.

    2015-12-01

    The calculation of mode propagation constants of elliptical core fibers has been the purpose of extended research leading to many notable methods, with the classic step index solution based on Mathieu functions. This paper seeks to derive a new innovative method for the determination of mode propagation constants in single mode fibers with elliptic core by modeling the elliptical fiber as a series of connected coupled transmission line elements. We develop a matrix formulation of the transmission line and the resonance of the circuits is used to calculate the mode propagation constants. The technique, used with success in the case of cylindrical fibers, is now being extended for the case of fibers with elliptical cross section. The advantage of this approach is that it is very well suited to be able to calculate the mode dispersion of arbitrary refractive index profile elliptical waveguides. The analysis begins with the deployment Maxwell's equations adjusted for elliptical coordinates. Further algebraic analysis leads to a set of equations where we are faced with the appearance of harmonics. Taking into consideration predefined fixed number of harmonics simplifies the problem and enables the use of the resonant circuits approach. According to each case, programs have been created in Matlab, providing with a series of results (mode propagation constants) that are further compared with corresponding results from the ready known Mathieu functions method.

  7. A transmission line model for propagation in elliptical core optical fibers

    International Nuclear Information System (INIS)

    Georgantzos, E.; Boucouvalas, A. C.; Papageorgiou, C.

    2015-01-01

    The calculation of mode propagation constants of elliptical core fibers has been the purpose of extended research leading to many notable methods, with the classic step index solution based on Mathieu functions. This paper seeks to derive a new innovative method for the determination of mode propagation constants in single mode fibers with elliptic core by modeling the elliptical fiber as a series of connected coupled transmission line elements. We develop a matrix formulation of the transmission line and the resonance of the circuits is used to calculate the mode propagation constants. The technique, used with success in the case of cylindrical fibers, is now being extended for the case of fibers with elliptical cross section. The advantage of this approach is that it is very well suited to be able to calculate the mode dispersion of arbitrary refractive index profile elliptical waveguides. The analysis begins with the deployment Maxwell’s equations adjusted for elliptical coordinates. Further algebraic analysis leads to a set of equations where we are faced with the appearance of harmonics. Taking into consideration predefined fixed number of harmonics simplifies the problem and enables the use of the resonant circuits approach. According to each case, programs have been created in Matlab, providing with a series of results (mode propagation constants) that are further compared with corresponding results from the ready known Mathieu functions method

  8. Cryogenic Fiber Optic Sensors for Superconducting Magnets and Power Transmission Lines in High Energy Physics Applications

    CERN Document Server

    AUTHOR|(CDS)2081689; Bajko, Marta

    In the framework of the Luminosity upgrade of the Large Hadron Collider (HL - LHC), a remarkable R&D effort is now ongoing at the European Organization for Nuclear Research (CERN) in order to develop a new generation of accelerator magnets and superconducting power transmission lines. The magnet technology will be based on Nb$_{3}$Sn enabling to operate in the 11 - 13 T range. In parallel, in order to preserve the power converters from the increasing radiation level, high power transmission lines are foreseen to feed the magnets from free - radiation zones. These will be based on high temperature superconductors cooled down with helium gas in the range 5 - 30 K. The new technologies will require advanced design and fabrication approaches as well as adapted instrumentation for monitoring both the R&D phase and operation. Resistive sensors have been used so far for voltage, temperature and strain monitoring but their integration still suffers from the number of electrical wires and the complex compensat...

  9. The Optical Transmission Spectrum of the Inflated Hot Jupiter WASP-94Ab

    Science.gov (United States)

    Berta-Thompson, Zachory; Diamond-Lowe, Hannah; Osip, David; McDonald, Michael; Triaud, Amaury; Hellier, Coel; Gillon, Michael; Delrez, Laetitia; Queloz, Didier; Neveu-VanMalle, Marion; Demory, Brice-Olivier

    2018-01-01

    Exoplaneteers study the color of sunset on other planets, by measuring the wavelength-dependence of the fraction of starlight transmitted through the planets' atmospheres during transit. These transmission spectroscopy observations can reveal the molecular composition and aerosol distribution along the planet's day-night terminator. Here, we present new observations of the transmission spectrum of WASP-94Ab, an inflated hot Jupiter in a 3.95 day orbit around a bright 6200K, V=10.1 dwarf star. The star is in a visual binary with a nearly identical star (6100K, V=10.5) located 15" away. We observed three transits of WASP-94Ab with the Magellan/LDSS3C multiobject spectrograph, taking advantage of the nearby companion to correct for temporal variations in Earth's telluric spectrum. Thanks to the Magellan Clay telescope's large 6.5m aperture and WASP-94Ab's low surface gravity, we achieve a spectrophotometric precision (in units of atmospheric scale heights) that rivals Hubble/STIS spectroscopy of the famous and much brighter hot Jupiter system HD209458b. We highlight the valuable role ground-based telescopes can play for exoplanetary characterization in the TESS era.

  10. Suppression of laser phase noise in direct-detection optical OFDM transmission using phase-conjugated pilots

    Science.gov (United States)

    Zhang, Lu; Ming, Yi; Li, Jin

    2017-11-01

    Due to the unique phase noise (PN) characteristics in direct-detection optical OFDM (DDO-OFDM) systems, the design of PN compensator is considered as a difficult task. In this paper, a laser PN suppression scheme with low complexity for DDO-OFDM based on coherent superposition of data carrying subcarriers and their phase conjugates is proposed. Through theoretical derivation, the obvious PN suppression is observed. The effectiveness of this technique is demonstrated by simulation of a 4-QAM DDO-OFDM system over 1000 km transmission length at different laser line-width and subcarrier frequency spacing. The results show that the proposed scheme can significantly suppress both varied phase rotation term (PTR) and inter-carrier interference (ICI), and the laser line-width can be relaxed with up to 9 dB OSNR saving or even breakthrough of performance floor.

  11. Null testing of nonrotational symmetry transmission optical freeform: design, modeling, and inspection on the basis of Fermat principles

    Science.gov (United States)

    Qiu, Gufeng; Cui, Xudong

    2015-11-01

    We present a general design method for a type of transmission freeforms without rotational symmetry and achieve the null testing by putting a well-designed Fermat reflector on the transmitting optical path. The design principle of the reflector is given, and an eccentric spherical surface with 1-mm deviation is used as an example of testing freeform. We fabricated the reflector and the freeform with the single-point diamond turning machine. Both conventional interference inspection and our approach give consistent results. The design error is less than 106 mm, and the measurement accuracy is nearly completely determined by the fabrication precision. This approach can also be applied to the inspections of reflecting freeforms with low costs.

  12. 1.28 Tbit/s/channel single-polarization DQPSK transmission over 525 km using ultrafast time-domain optical Fourier transformation

    DEFF Research Database (Denmark)

    Guan, P.; Mulvad, Hans Christian Hansen; Tomiyama, Y.

    2010-01-01

    A single-channel 1.28 Tbit/s transmission over 525 km is demonstrated for the first time with a single-polarization DQPSK signal. Ultrafast time-domain optical Fourier transformation is successfully applied to DQPSK signals and results in improved performance and increased system margin.......A single-channel 1.28 Tbit/s transmission over 525 km is demonstrated for the first time with a single-polarization DQPSK signal. Ultrafast time-domain optical Fourier transformation is successfully applied to DQPSK signals and results in improved performance and increased system margin....

  13. Active photonic sensor communication cable for field application of optical data and power transmission

    Science.gov (United States)

    Suthau, Eike; Rieske, Ralf; Zerna, Thomas

    2014-10-01

    Omitting electrically conducting wires for sensor communication and power supply promises protection for sensor systems and monitored structures against lightning or high voltages, prevention of explosion hazards, and reduction of susceptibility to tampering. The ability to photonically power remote systems opens up the full range of electrical sensors. Power-over-fiber is an attractive option in electromagnetically sensitive environments, particularly for longterm, maintenance-free applications. It can deliver uninterrupted power sufficient for elaborate sensors, data processing or even actuators alongside continuous high speed data communication for remote sensor application. This paper proposes an active photonic sensor communication system, which combines the advantages of optical data links in terms of immunity to electromagnetic interference (EMI), high bandwidth, hardiness against tampering or eavesdropping, and low cable weight with the robustness one has come to expect from industrial or military electrical connectors. An application specific integrated circuit (ASIC) is presented that implements a closed-loop regulation of the sensor power supply to guarantee continuous, reliable data communications while maintaining a highly efficient, adaptive sensor supply scheme. It is demonstrated that the resulting novel photonic sensor communication cable can handle sensors and actuators differing orders of magnitude with respect to power consumption. The miniaturization of the electro-optical converters and driving electronics is as important to the presented development as the energy efficiency of the detached, optically powered sensor node. For this reason, a novel photonic packaging technology based on wafer-level assembly of the laser power converters by means of passive alignment will be disclosed in this paper.

  14. Quasi-Optical Transmission Lines for ECRH on TJ-II Stellarator

    International Nuclear Information System (INIS)

    Fernandez, A.; Likin, K.; Martin, R.; Cappa, A.; Cepero, J.R.

    1999-01-01

    Two mirror lines are used to transmit ht microwave power from the powerful microwave generators to the TJ-II plasmas. Both lines have been tested at nominal power level and they are now in operation. This paper is devoted to the final design of the transmission lines and their testing. Before starting operation at high power level measurements of the wave beam parameters at low power level were made. Two horn antennae were designed to simulate the gyrotron output. Numerical simulations of the far field radiation pattern of the antennae were made, a computer code based on Huygens diffraction theory was developed to simulate the propagation of the beam along a mirror line. A comparison of the theoretical and the experimental results is also presented here. (Author)

  15. Modified hybrid subcarrier/amplitude/ phase/polarization LDPC-coded modulation for 400 Gb/s optical transmission and beyond.

    Science.gov (United States)

    Batshon, Hussam G; Djordjevic, Ivan; Xu, Lei; Wang, Ting

    2010-06-21

    In this paper, we present a modified coded hybrid subcarrier/ amplitude/phase/polarization (H-SAPP) modulation scheme as a technique capable of achieving beyond 400 Gb/s single-channel transmission over optical channels. The modified H-SAPP scheme profits from the available resources in addition to geometry to increase the bandwidth efficiency of the transmission system, and so increases the aggregate rate of the system. In this report we present the modified H-SAPP scheme and focus on an example that allows 11 bits/Symbol that can achieve 440 Gb/s transmission using components of 50 Giga Symbol/s (GS/s).

  16. High-transmission excited-state Faraday anomalous dispersion optical filter edge filter based on a Halbach cylinder magnetic-field configuration.

    Science.gov (United States)

    Rudolf, Andreas; Walther, Thomas

    2012-11-01

    We report on the realization of an excited-state Faraday anomalous dispersion optical filter (ESFADOF) edge filter based on the 5P(3/2)→8D(5/2) transition in rubidium. A maximum transmission of 81% has been achieved. This high transmission is only possible by utilizing a special configuration of magnetic fields taken from accelerator physics to provide a strong homogeneous magnetic field of approximately 6000 G across the vapor cell. The two resulting steep transmission edges are separated by more than 13 GHz, enabling its application in remote sensing.

  17. Metallic attenuated total reflection infrared hollow fibers for robust optical transmission systems

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Chengbin; Guo, Hong; Hu, Zhigao; Yang, Pingxiong [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241 (China); Chu, Junhao [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai 200083 (China); Liu, Aiyun [Department of Physics, Shanghai Normal University, 100 Gui Lin Road, Shanghai 200234 (China); Shi, Yiwei [School of Information Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433 (China)

    2014-07-07

    A durable metallic attenuated total reflection (ATR) hollow fiber (bore size: 1.45 mm, wall thickness: 50 μm) was designed and fabricated based on a nickel capillary tube and hexagonal germanium dioxide (GeO{sub 2}). The anomalous dispersion of the hexagonal GeO{sub 2} layer grown inside a nickel tube achieves low-loss light transmission at two peak-power wavelengths for CO{sub 2} laser devices (10.2 and 10.6 μm). An 11–28 W, 10.2 or 10.6 μm CO{sub 2} laser power was steadily delivered via a fiber elastically bent from 0° to 90° (radius: 45 cm) for over 40 min (transmission loss: 0.22 to 4.2 dB/m). Theoretically fitting the measured temperatures showed that front-end clipping caused greater thermal loading than the distributed mode absorption. The maximum external temperature of a nickel ATR fiber is much lower than that of a silica glass ATR fiber owing to their different heat dissipation abilities. The HE{sub 11} mode purity of the output beam profiles decreased from 90.3% to 44.7% as the bending angle increased from 0° to 90°. Large core sizes and wall roughnesses (scattering loss 0.04 dB/m) contributed to mode mixing and excess losses that were above the value predicted by the classical Marcatili and Schmeltzer equation (0.024–0.037 dB/m).

  18. Signal transmission in a human body medium-based body sensor network using a Mach-Zehnder electro-optical sensor.

    Science.gov (United States)

    Song, Yong; Hao, Qun; Zhang, Kai; Wang, Jingwen; Jin, Xuefeng; Sun, He

    2012-11-30

    The signal transmission technology based on the human body medium offers significant advantages in Body Sensor Networks (BSNs) used for healthcare and the other related fields. In previous works we have proposed a novel signal transmission method based on the human body medium using a Mach-Zehnder electro-optical (EO) sensor. In this paper, we present a signal transmission system based on the proposed method, which consists of a transmitter, a Mach-Zehnder EO sensor and a corresponding receiving circuit. Meanwhile, in order to verify the frequency response properties and determine the suitable parameters of the developed system, in-vivo measurements have been implemented under conditions of different carrier frequencies, baseband frequencies and signal transmission paths. Results indicate that the proposed system will help to achieve reliable and high speed signal transmission of BSN based on the human body medium.

  19. Optical design and development of a fiber coupled high-power diode laser system for laser transmission welding of plastics

    Science.gov (United States)

    Rodríguez-Vidal, Eva; Quintana, Iban; Etxarri, Jon; Azkorbebeitia, Urko; Otaduy, Deitze; González, Francisco; Moreno, Fernando

    2012-12-01

    Laser transmission welding (LTW) of thermoplastics is a direct bonding technique already used in different industrial applications sectors such as automobiles, microfluidics, electronics, and biomedicine. LTW evolves localized heating at the interface of two pieces of plastic to be joined. One of the plastic pieces needs to be optically transparent to the laser radiation whereas the other part has to be absorbent, being that the radiation produced by high power diode lasers is a good alternative for this process. As consequence, a tailored laser system has been designed and developed to obtain high quality weld seams with weld widths between 0.7 and 1.4 mm. The developed laser system consists of two diode laser bars (50 W per bar) coupled into an optical fiber using a nonimaging solution: equalization of the beam parameter product (BPP) in the slow and fast axes by a pair of step-mirrors. The power scaling was carried out by means of a multiplexing polarization technique. The analysis of energy balance and beam quality was performed considering ray tracing simulation (ZEMAX) and experimental validation. The welding experiments were conducted on acrylonitrile/butadiene/styrene (ABS), a thermoplastic frequently used in automotive, electronics and aircraft applications, doped with two different concentrations of carbon nanotubes (0.01% and 0.05% CNTs). Quality of the weld seams on ABS was analyzed in terms of the process parameters (welding speed, laser power and clamping pressure) by visual and optical microscope inspections. Mechanical properties of weld seams were analyzed by mechanical shear tests. High quality weld seams were produced in ABS, revealing the potential of the laser developed in this work for a wide range of plastic welding applications.

  20. Reduced optical transmission of SiO2 fibers used in controlled fusion diagnostics

    International Nuclear Information System (INIS)

    Ramsey, A.T.; Adler, H.G.; Hill, K.W.

    1993-02-01

    We have subjected a silica core fiber optic cable to 4 years of low-level neutron and gamma radiation from Princeton's TFTR controlled fusion experiment The accumulated dose was 200 Gy. As a result of the radiation, we have measured increased attenuations of 100--300 db/km in the visible part of the spectrum, and a decrease of the numerical aperture. An attempt to decrease this damage by photobleaching failed. We argue that this failure is not unexpected, since the rate of damage is so slow and the time scale so long that the self-annealing process keeps the residual damage at the irreducible level seen in other experiments. The implications of these findings for controlled fusion diagnostics during upcoming experiments with highly reactive deuterium-tritium plasmas are discussed

  1. Advanced digital signal processing for short haul optical fiber transmission beyond 100G

    Science.gov (United States)

    Kikuchi, Nobuhiko

    2017-01-01

    Significant increase of intra and inter data center traffic has been expected by the rapid spread of various network applications like SNS, IoT, mobile and cloud computing, and the needs for ultra-high speed and cost-effective short- to medium-reach optical fiber links beyond 100-Gbit/s is becoming larger and larger. Such high-speed links typically use multilevel modulation to lower signaling speed, which in turn face serious challenges in limited loss budget and waveform distortion tolerance. One of the promising techniques to overcome them is the use of advanced digital signal processing (DSP) and we review various DSP applications for short-to-medium reach applications.

  2. Real-time dual-polarization transmission based on hybrid optical wireless communications

    Science.gov (United States)

    Sousa, Artur N.; Alimi, Isiaka A.; Ferreira, Ricardo M.; Shahpari, Ali; Lima, Mário; Monteiro, Paulo P.; Teixeira, António L.

    2018-01-01

    We present experimental work on a gigabit-capable and long-reach hybrid coherent UWDM-PON plus FSO system for supporting different applications over the same fiber infrastructure in the mobile backhaul (MBH) networks. Also, for the first time, we demonstrate a reconfigurable real-time DSP transmission/reception of DP-QPSK signals over standard single-mode fiber (SSMF) and FSO links. The receiver presented is based on a commercial field-programmable gate array (FPGA). The considered communication links are based on 20 UDWDM channels with 625 Mbaud and 2.5 GHz channel spacing. We are able to demonstrate the lowest sampling rate required for digital coherent PON by employing four 1.25 Gsa/s ADCs using an electrical front-end receiver that offers only 1 GHz analog bandwidth. We achieved this by implementing a phase and polarization diversity coherent receiver combined with the DP-QPSK modulation formats. The system performance is estimated in terms of receiver sensitivity. The results show the viability of coherent PON and flexible dual-polarization supported by software-defined transceivers for the MBH.

  3. Advances in coherent optical modems and 16-QAM transmission with feedforward carrier recovery

    Science.gov (United States)

    Noé, Reinhold; Hoffmann, Sebastian; Wördehoff, Christian; Al-Bermani, Ali; El-Darawy, Mohamed

    2011-01-01

    Polarization multiplexing and quadrature phase shift keying (QPSK) both double spectral efficiency. Combined with synchronous coherent polarization diverse intradyne receivers this modulation format is ultra-robust and cost-efficient. A feedforward carrier recovery is required in order to tolerate phase noise of normal DFB lasers. Signal processing in the digital domain permits compensation of at least chromatic and polarization mode dispersion. Some companies have products on the market, others are working on them. For 100 GbE transmission, 50 GHz channel spacing is sufficient. 16ary quadrature amplitude modulation (16-QAM) is attractive to double capacity once more, possibly in a modulation format flexible transponder which is switched down to QPSK only if system margin is too low. For 16-QAM the phase noise problem is sharply increased. However, also here a feedforward carrier recovery has been implemented. A number of carrier phase angles is tested in parallel, and the recovered data is selected for that phase angle where squared distance of recovered data to the nearest constellation point, averaged over a number of symbols, is minimum. An intradyne/selfhomodyne synchronous coherent 16-QAM experiment (2.5 Gb/s, 81 km) is presented.

  4. Magneto-optical transmission-reflection beam splitter for multi-level atoms

    International Nuclear Information System (INIS)

    Murphy, J.E.; Goodman, P.; Sidorov, A.I.

    1994-01-01

    An atomic de Broglie wave beam splitter is proposed. The interaction of multi-level atoms (J g = 1 - J e = 0) with a laser beam in the presence of a static magnetic field leads to the partial transmission and reflection of the atomic beam. The coherent splitting of the atomic beam occurs due to non-adiabatic transitions between different dressed states in the vicinity of avoided crossings. The transition probabilities and populations of split beams are dependent on the value of the magnetic field, laser detuning, and the ratio between different polarization components in the laser beam. For optimal conditions the population of each of the two transmitted and two reflected beams is 25 per cent. For cooled atoms it is possible to obtain splitting angles of 80 mrad. The effect of spontaneous emission during the atom-light interaction was estimated and for a reasonable detuning losses were reduced to less than 10 per cent. 14 refs., 1 tab., 6 figs

  5. Adaptation of AMO-FBMC-OQAM in optical access network for accommodating asynchronous multiple access in OFDM-based uplink transmission

    Science.gov (United States)

    Jung, Sun-Young; Jung, Sang-Min; Han, Sang-Kook

    2015-01-01

    Exponentially expanding various applications in company with proliferation of mobile devices make mobile traffic exploded annually. For future access network, bandwidth efficient and asynchronous signals converged transmission technique is required in optical network to meet a huge bandwidth demand, while integrating various services and satisfying multiple access in perceived network resource. Orthogonal frequency division multiplexing (OFDM) is highly bandwidth efficient parallel transmission technique based on orthogonal subcarriers. OFDM has been widely studied in wired-/wireless communication and became a Long term evolution (LTE) standard. Consequently, OFDM also has been actively researched in optical network. However, OFDM is vulnerable frequency and phase offset essentially because of its sinc-shaped side lobes, therefore tight synchronism is necessary to maintain orthogonality. Moreover, redundant cyclic prefix (CP) is required in dispersive channel. Additionally, side lobes act as interference among users in multiple access. Thus, it practically hinders from supporting integration of various services and multiple access based on OFDM optical transmission In this paper, adaptively modulated optical filter bank multicarrier system with offset QAM (AMO-FBMC-OQAM) is introduced and experimentally investigated in uplink optical transmission to relax multiple access interference (MAI), while improving bandwidth efficiency. Side lobes are effectively suppressed by using FBMC, therefore the system becomes robust to path difference and imbalance among optical network units (ONUs), which increase bandwidth efficiency by reducing redundancy. In comparison with OFDM, a signal performance and an efficiency of frequency utilization are improved in the same experimental condition. It enables optical network to effectively support heterogeneous services and multiple access.

  6. Thermometer by optical fiber for ampacity studies in overhead transmission lines; Termometro a fibra optica para estudo da ampacidade em linhas de transmissao aereas

    Energy Technology Data Exchange (ETDEWEB)

    Valente, L.C.G.; Kawase, L.R.; Silva Filho, J.I. da; Silva, J.M.M. da [Centro de Pesquisas de Energia Eletrica, Rio de Janeiro, RJ (Brazil); Igarashi, A.Y. [Universidade Federal, Rio de Janeiro, RJ (Brazil)

    1995-12-31

    This article suggests the utilization of thermometers constructed from optical fibers technology in overhead power transmission lines. This will help the studies in progress about the electric power systems ampacity. It also presents the advantages of using optical fibers instead of conventional thermometers. As an example, the fact that the optical fibers are dielectric and make possible the remote monitoring. It is also shown a possibility of introducing such measuring system in electric junctions where OPGW cables are used 4 refs., 4 figs.; e-mail: liliana at fis.puc-rio.br

  7. Transmission lines with lightning arresters cables energized by optical fibers; Linhas de transmissao com cabos para-raios energizados com fibra optica

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Fumitaka; Cicarelli, Liliane Dias [Alcoa Aluminio S.A. (Brazil); D`Ajuz, Ary [ELETRONORTE, Belem, PA (Brazil); Martinez, Manuel L.B. [Escola Federal de Engenharia de Itajuba, MG (Brazil); Masuda, Mario [Tecname Engenharia (Brazil)

    1995-12-31

    Recently, the implementation of optical systems has been possible through the utilization of the existent transmission lines structure by the sharing between electric power and telecommunications enterprises, using Op-GW cables instead of conventional lightning-arresters cables. In order to make such optical sharing feasible, the enterprise ALCOA Aluminio S.A is developing the energized lightning-arrester system with optical fiber in it. This work presents such system and show its great advantages specially when implemented in low population density regions in order to supply electric power demand at lower costs 6 refs., 5 figs.

  8. Comparison of OOK- and PAM-4 modulation for 10 Gbit/s transmission over up to 300 m polymer optical fiber

    NARCIS (Netherlands)

    Breyer, F.; Lee, S.C.J.; Randel, S.; Hanik, N.

    2008-01-01

    10 Gbit/s Transmission over up to 300 m of multimode 62.5 µm core-diameter perfluorinated graded-index polymer optical fiber is compared using on-off-keying (OOK) or 4-level pulse amplitude modulation (PAM-4) and feed-forward or decision-feedback equalization.

  9. Experimental Performance Comparison of 60 GHz DCM OFDM and Impulse BPSK Ultra-Wideband with Combined Optical Fibre and Wireless Transmission

    DEFF Research Database (Denmark)

    Beltrán, Marta; Jensen, Jesper Bevensee; Yu, Xianbin

    2010-01-01

    We present an experimental performance comparison of 1.44Gbps dual-carrier modulation OFDM and BPSK impulse-radio ultra-wideband in the 60GHz band with combined fibre, up to 40km, and 5m wireless transmission. Impulse-radio exhibits better dispersion tolerance requiring lower optical power....

  10. Radiation-hard ASICs for optical data transmission in the first phase of the LHC upgrade

    International Nuclear Information System (INIS)

    Gan, K.K.; Buchholz, P.; Kagan, H.P.; Kass, R.D.; Moore, J.R.; Smith, D.S.; Wiese, A.; Ziolkowskic, M.

    2011-01-01

    We have designed two ASICs for possible applications in the optical links of a new layer of the pixel detector to be install inside the ATLAS Pixel detector for the first phase of the LHC luminosity upgrade. The ASICs include a high-speed driver for a VCSEL and a receiver/decoder to decode the signal received at a PIN diode to extract the data and clock. Both ASICs contain 4 channels for operation with a VCSEL or PIN array. The ASICs were designed using a 130 nm CMOS process to enhance the radiation-hardness. We have characterized the fabricated ASICs and the performance of the ASICs is satisfactory. The receiver/decoder properly decodes the bi-phase marked input stream with low PIN current and the driver can operate a VCSEL up to ∼5 Gb/s. The added functionalities are also successful, including redundancy to bypass a broken VCSEL or PIN channel, individual control of VCSEL current, and power-on reset circuit to set all VCSEL currents to a nominal value.

  11. Radiation-hard ASICs for optical data transmission in the first phase of the LHC upgrade

    International Nuclear Information System (INIS)

    Gan, K K; Kagan, H P; Kass, R D; Moore, J R; Smith, D S; Buchholz, P; Wiese, A; Ziolkowskic, M

    2010-01-01

    We have designed two ASICs for possible applications in the optical links of a new layer of the pixel detector to be install inside the ATLAS Pixel detector for the first phase of the LHC luminosity upgrade. The ASICs include a high-speed driver for the VCSEL and a receiver/decoder to decode the signal received at the PIN diode to extract the data and clock. Both ASICs contain 4 channels for operation with a VCSEL or PIN array. The ASICs were designed using a 130 nm CMOS process to enhance the radiation-hardness. We have characterized the fabricated ASICs and the performance of the ASICs is satisfactory. The receiver/decoder can properly decode the bi-phase marked input stream with low PIN current and the driver can operate a VCSEL up to ∼ 5 Gb/s. The added functionalities are also successful, including redundancy to bypass a broken VCSEL or PIN channel, individual control of VCSEL current, and power-on reset circuit to set all VCSEL currents to a nominal value. The ASICs were irradiated to a dose of 46 Mrad with 24 GeV/c protons. The observed modest degradation is acceptable and the single event upset rate is negligible.

  12. Radiation-hard ASICs for optical data transmission in the first phase of the LHC upgrade

    CERN Document Server

    Gan, K K; Kagan, H P; Kass, R D; Moore, J R; Smith, D S; Wiese, A; Ziolkowskic, M; 10.1088/1748-0221/5/12/C12006

    2010-01-01

    We have designed two ASICs for possible applications in the optical links of a new layer of the pixel detector to be install inside the ATLAS Pixel detector for the first phase of the LHC luminosity upgrade. The ASICs include a high-speed driver for the VCSEL and a receiver/decoder to decode the signal received at the PIN diode to extract the data and clock. Both ASICs contain 4 channels for operation with a VCSEL or PIN array. The ASICs were designed using a 130 nm CMOS process to enhance the radiation-hardness. We have characterized the fabricated ASICs and the performance of the ASICs is satisfactory. The receiver/decoder can properly decode the bi-phase marked input stream with low PIN current and the driver can operate a VCSEL up to ~ 5 Gb/s. The added functionalities are also successful, including redundancy to bypass a broken VCSEL or PIN channel, individual control of VCSEL current, and power-on reset circuit to set all VCSEL currents to a nominal value. The ASICs were irradiated to a dose of 46 Mrad ...

  13. Calculated efficiencies of three-material low stress coatings for diffractive x-ray transmission optics

    International Nuclear Information System (INIS)

    Kubec, Adam; Braun, Stefan; Gawlitza, Peter; Menzel, Maik; Leson, Andreas

    2016-01-01

    Diffractive X-ray optical elements made by thin film coating techniques such as multilayer Laue lenses (MLL) and multilayer zone plates (MZP) are promising approaches to achieve resolutions in hard X-ray microscopy applications of less than 10 nm. The challenge is to make a lens with a large numerical aperture on the one hand and a decent working distance on the other hand. One of the limiting factors with the coated structures is the internal stress in the films, which can lead to significant bending of the substrate and various types of unwanted diffraction effects. Several approaches have been discussed to overcome this challenge. One of these is a three-material combination such as Mo/MoSi_2/Si, where four single layers per period are deposited. Mo and Si represent the absorber and spacer in this case while MoSi_2 forms a diffusion barrier; in addition the thicknesses of absorber and spacer are chosen to minimize residual stress of the overall coating. Here the diffraction efficiency as well as the profile of the beam in the focal plane are discussed in order to find a tradeoff between lowest residual stress and best diffraction properties.

  14. Packaged semiconductor laser optical phase locked loop for photonic generation, processing and transmission of microwave signals

    DEFF Research Database (Denmark)

    Langley, L.N.; Elkin, M.D.; Edege, C.

    1999-01-01

    In this paper, we present the first fully packaged semiconductor laser optical phase-locked loop (OPLL) microwave photonic transmitter. The transmitter is based on semiconductor lasers that are directly phase locked without the use of any other phase noise-reduction mechanisms. In this transmitter......, the lasers have a free-running summed linewidth of 6 MHz and the OPLL has a feedback bandwidth of 70 MHz, A state-of-the-art performance is obtained, with a total phase-error variance of 0.05 rad(2) (1-GHz bandwidth) and a carrier phase-error variance of 7x10(-4) rad(2) in a 15-MHz bandwidth. Carriers...... are generated in the range of 7-14 GHz. The OPLL transmitter has been fully packaged for practical use in field trials. This is the first time this type of transmitter has been fabricated in a packaged state which is a significant advance on the route to practical application....

  15. Extraordinary magnetoresistance in semiconductor/metal hybrids: A review

    KAUST Repository

    Sun, J.; Kosel, Jü rgen

    2013-01-01

    The Extraordinary Magnetoresistance (EMR) effect is a change in the resistance of a device upon the application of a magnetic field in hybrid structures, consisting of a semiconductor and a metal. The underlying principle of this phenomenon is a

  16. Full-duplex bidirectional transmission of 10-Gb/s millimeter-wave QPSK signal in E-band optical wireless link.

    Science.gov (United States)

    Fang, Yuan; Yu, Jianjun; Chi, Nan; Xiao, Jiangnan

    2014-01-27

    We experimentally demonstrated full-duplex bidirectional transmission of 10-Gb/s millimeter-wave (mm-wave) quadrature phase shift keying (QPSK) signal in E-band (71-76 GHz and 81-86 GHz) optical wireless link. Single-mode fibers (SMF) are connected at both sides of the antenna for uplink and downlink which realize 40-km SMF and 2-m wireless link for bidirectional transmission simultaneously. We utilized multi-level modulation format and coherent detection in such E-band optical wireless link for the first time. Mm-wave QPSK signal is generated by photonic technique to increase spectrum efficiency and received signal is coherently detected to improve receiver sensitivity. After the coherent detection, digital signal processing is utilized to compensate impairments of devices and transmission link.

  17. Visualizing Space Plasmas and Particles: Extraordinary Matter

    Science.gov (United States)

    Barbier, B.; Bartolone, L. M.; Christian, E. R.; Eastman, T. E.; Lewis, E.; Thieman, J. R.

    2010-12-01

    A recent survey of museum visitors documented some startling misconceptions at a very basic level. Even in this "science attentive" group, one quarter of the respondents believed that an atom would explode if it lost an electron, one sixth said it would become a new atom or element, and one fifth said they had no idea what would happen. Only one fourth of the respondents indicated they were familiar with plasma as a state of matter. Current resources on these topics are few in number and/or are difficult to locate, and they rarely provide suitable context at a level understandable to high school students and educators or to the interested public. In response to this and other evidence of common misunderstandings of simple particle and plasma science, our team of space scientists and education specialists has embarked upon the development of "Extraordinary Matter: Visualizing Space Plasmas and Particles", an online NASA multimedia library. It is designed to assist formal and informal educators and scientists with explaining concepts that cannot be easily demonstrated in the everyday world. The newly released site, with a target audience equivalent to grades 9-14, includes both existing products, reviewed by our team for quality, and new products we have developed. Addition of products to our site is in large part determined by the results of our front-end evaluation to determine the specific needs, gaps, and priorities of potential audiences. Each ready-to-use product is accompanied by a supporting explanation at a reading level matching the educational level of the concept, along with educational standards addressed, and links to other associated resources. Some will include related educational activities. Products are intended to stand alone, making them adaptable to the widest range of uses, either individually or as a custom-selected group. Uses may include, for example, scientist presentations, museum displays, teacher professional development, and classroom

  18. Synchronic, optical transmission data link integrated with FPGA circuits (for TESLA LLRF control system)

    Energy Technology Data Exchange (ETDEWEB)

    Zielinski, J.S.

    2006-07-15

    The X-ray free-electron laser X-FEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new possibilities for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated to the LLRF1 system in VUV FEL experiment It is being developed by the ELHEP2 group in the Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller to stabilize the vector sum of fields in cavities of one cryo-module in the experiment. The device can be also used as the simulator of the cavity and test bench for other devices. The synchronic, optical link project was made for the accelerator X-FEL laser TESLA, the LLRF control system experiment at DESY, Hamburg. The control and diagnostic data is transmitted up to 2.5Gbit/s through a plastic fiber in a distance up to a few hundred meters. The link is synchronized once after power up, and never resynchronized when data is transmitted with maximum speed. The one way link bit error rate is less then 10{sup -15}. The transceiver component written in VHDL that works in the dedicated Altera registered Stratix registered GX FPGA circuit. During the work in the PERG laboratory a 2,5Gbit/s serial link with the long vector parallel interface transceiver was created. Long-Data-Vector transceiver transmits 16bit vector each 8ns with 120ns latency. (orig.)

  19. Synchronic, optical transmission data link integrated with FPGA circuits (for TESLA LLRF control system)

    International Nuclear Information System (INIS)

    Zielinski, J.S.

    2006-05-01

    The X-ray free-electron laser X-FEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new possibilities for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated to the LLRF1 system in VUV FEL experiment It is being developed by the ELHEP2 group in the Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller to stabilize the vector sum of fields in cavities of one cryo-module in the experiment. The device can be also used as the simulator of the cavity and test bench for other devices. The synchronic, optical link project was made for the accelerator X-FEL laser TESLA, the LLRF control system experiment at DESY, Hamburg. The control and diagnostic data is transmitted up to 2.5Gbit/s through a plastic fiber in a distance up to a few hundred meters. The link is synchronized once after power up, and never resynchronized when data is transmitted with maximum speed. The one way link bit error rate is less then 10 -15 . The transceiver component written in VHDL that works in the dedicated Altera registered Stratix registered GX FPGA circuit. During the work in the PERG laboratory a 2,5Gbit/s serial link with the long vector parallel interface transceiver was created. Long-Data-Vector transceiver transmits 16bit vector each 8ns with 120ns latency. (orig.)

  20. Dispersion-optimized optical fiber for high-speed long-haul dense wavelength division multiplexing transmission

    Science.gov (United States)

    Wu, Jindong; Chen, Liuhua; Li, Qingguo; Wu, Wenwen; Sun, Keyuan; Wu, Xingkun

    2011-07-01

    Four non-zero-dispersion-shifted fibers with almost the same large effective area (Aeff) and optimized dispersion properties are realized by novel index profile designing and modified vapor axial deposition and modified chemical vapor deposition processes. An Aeff of greater than 71 μm2 is obtained for the designed fibers. Three of the developed fibers with positive dispersion are improved by reducing the 1550nm dispersion slope from 0.072ps/nm2/km to 0.063ps/nm2/km or 0.05ps/nm2/km, increasing the 1550nm dispersion from 4.972ps/nm/km to 5.679ps/nm/km or 7.776ps/nm/km, and shifting the zero-dispersion wavelength from 1500nm to 1450nm. One of these fibers is in good agreement with G655D and G.656 fibers simultaneously, and another one with G655E and G.656 fibers; both fibers are beneficial to high-bit long-haul dense wavelength division multiplexing systems over S-, C-, and L-bands. The fourth developed fiber with negative dispersion is also improved by reducing the 1550nm dispersion slope from 0.12ps/nm2/km to 0.085ps/nm2/km, increasing the 1550nm dispersion from -4ps/nm/km to -6.016ps/nm/km, providing facilities for a submarine transmission system. Experimental measurements indicate that the developed fibers all have excellent optical transmission and good macrobending and splice performances.

  1. The Multi-Functional Foot in Athletic Movement: Extraordinary Feats by Our Extraordinary Feet

    Directory of Open Access Journals (Sweden)

    Wilson Jennifer

    2016-03-01

    Full Text Available The unique architecture of the foot system provides a sensitive, multi-tensional method of communicating with the surrounding environment. Within the premise of the paper, we discuss three themes: complexity, degeneracy and bio-tensegrity. Complex structures within the foot allow the human movement system to negotiate strategies for dynamic movement during athletic endeavours. We discuss such complex structures with particular attention to properties of a bio-tensegrity system. Degeneracy within the foot structure offers a distinctive solution to the problems posed by differing terrains and uneven surfaces allowing lower extremity structures to overcome perturbation as and when it occurs. This extraordinary structure offers a significant contribution to bipedalism through presenting a robust base of support and as such, should be given more consideration when designing athletic development programmes.

  2. 55th electric science promotion prize (progress prize). Demonstration of optical soliton transmission on OPGW first in the world; Dai 55 kai denki gakujutsu shinkosho (shinposho) jusho. Seiaihatsu no OPGW ni okeru hikari soriton denso no jissho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-06-10

    Electric science promotion prize (progress prize) is given to `Person who newly proposed a new concept, theory, material, device, system and method on electrical science and technology, or demonstrated these proposals` by the commendation committee of Institute of Electrical Engineers of Japan every year. Eight promotion prizes including that for Kansai Electric Power`s `Demonstration of optical soliton transmission on OPGW first in the world` were given. This research succeeded in development of the transmission/ receiving device suitable for optical soliton transmission, and the prediction method of an optimum transmission condition by computer simulation. In addition, this research succeeded in 10Gbit transmission of 784km and 40Gbit transmission (4-wave multiplex) of 392km by applying the above research result to Okurobe trunk line OPGW (98.2km). This demonstration of optical soliton transmission on OPGW is first in the world. (NEDO)

  3. Continuous single pulse resolved measurement of beam diameters at 200 kHz using optical transmission filters

    Science.gov (United States)

    Fruechtenicht, Johannes; Letsch, Andreas; Voss, Andreas; Abdou Ahmed, Marwan; Graf, Thomas

    2012-02-01

    We present a novel laser beam measurement setup which allows the determination of the beam diameter for each single pulse of a pulsed laser beam at repetition rates of up to 200 kHz. This is useful for online process-parameter control e.g. in micromachining or for laser source characterization. Basically, the developed instrument combines spatial transmission filters specially designed for instantaneous optical determination of the second order moments of the lateral intensity distribution of the light beam and photodiodes coupled to customized electronics. The acquisition is computer-based, enabling real-time operation for online monitoring or control. It also allows data storage for a later analysis and visualization of the measurement results. The single-pulse resolved beam diameter can be measured and recorded without any interruption for an unlimited number of pulses. It is only limited by the capacity of the data storage means. In our setup a standard PC and hard-disk provided 2 hours uninterrupted operation and recording of varying beam diameters at 200 kHz. This is about three orders of magnitude faster than other systems. To calibrate our device we performed experiments in cw and pulsed regimes and the obtained results were compared to those obtained with a commercial camera based system. Only minor deviations of the beam diameter values between the two instruments were observed, proving the reliability of our approach.

  4. Spectral analysis of the UFBG-based acousto—optical modulator in V-I transmission matrix formalism

    Science.gov (United States)

    Wu, Liang-Ying; Pei, Li; Liu, Chao; Wang, Yi-Qun; Weng, Si-Jun; Wang, Jian-Shuai

    2014-11-01

    In this study, the V-I transmission matrix formalism (V-I method) is proposed to analyze the spectrum characteristics of the uniform fiber Bragg grating (FBG)-based acousto—optic modulators (UFBG-AOM). The simulation results demonstrate that both the amplitude of the acoustically induced strain and the frequency of the acoustic wave (AW) have an effect on the spectrum. Additionally, the wavelength spacing between the primary reflectivity peak and the secondary reflectivity peak is proportional to the acoustic frequency with the ratio 0.1425 nm/MHz. Meanwhile, we compare the amount of calculation. For the FBG whose period is M, the calculation of the V-I method is 4 × (2M-1) in addition/subtraction, 8 × (2M - 1) in multiply/division and 2M in exponent arithmetic, which is almost a quarter of the multi-film method and transfer matrix (TM) method. The detailed analysis indicates that, compared with the conventional multi-film method and transfer matrix (TM) method, the V-I method is faster and less complex.

  5. Spectral analysis of the UFBG-based acousto—optical modulator in V–I transmission matrix formalism

    International Nuclear Information System (INIS)

    Wu Liang-Ying; Pei Li; Liu Chao; Wang Yi-Qun; Weng Si-Jun; Wang Jian-Shuai

    2014-01-01

    In this study, the V–I transmission matrix formalism (V–I method) is proposed to analyze the spectrum characteristics of the uniform fiber Bragg grating (FBG)-based acousto—optic modulators (UFBG-AOM). The simulation results demonstrate that both the amplitude of the acoustically induced strain and the frequency of the acoustic wave (AW) have an effect on the spectrum. Additionally, the wavelength spacing between the primary reflectivity peak and the secondary reflectivity peak is proportional to the acoustic frequency with the ratio 0.1425 nm/MHz. Meanwhile, we compare the amount of calculation. For the FBG whose period is M, the calculation of the V–I method is 4 × (2M–1) in addition/subtraction, 8 × (2M – 1) in multiply/division and 2M in exponent arithmetic, which is almost a quarter of the multi-film method and transfer matrix (TM) method. The detailed analysis indicates that, compared with the conventional multi-film method and transfer matrix (TM) method, the V–I method is faster and less complex. (general)

  6. Barrier Performance of CVD Graphene Films Using a Facile P3HT Thin Film Optical Transmission Test

    Directory of Open Access Journals (Sweden)

    Srinivasa Kartik Nemani

    2018-01-01

    Full Text Available The barrier performance of CVD graphene films was determined using a poly(3-hexylthiophene (P3HT thin film optical transmission test. P3HT is a semiconducting polymer that photo-oxidatively degrades upon exposure to oxygen and light. The polymer is stable under ambient conditions and indoor lighting, enabling P3HT films to be deposited and encapsulated in air. P3HT’s stability under ambient conditions makes it desirable for an initial evaluation of barrier materials as a complimentary screening method in combination with conventional barrier tests. The P3HT test was used to demonstrate improved barrier performance for polymer substrates after addition of CVD graphene films. A layer-by-layer transfer method was utilized to enhance the barrier performance of monolayer graphene. Another set of absorption measurements were conducted to demonstrate the barrier performance of graphene and the degradation mechanism of graphene/P3HT over multiple wavelengths from 400 to 800 nm. The absorption spectra for graphene/polymer composite were simulated by solving Fresnel equations. The simulation results were found to be in good agreement with the measured absorption spectra. The P3HT degradation results qualitatively indicate the potential of graphene films as a possible candidate for medium performance barriers.

  7. A 30 Gb/s full-duplex bi-directional transmission optical wireless-over fiber integration system at W-band.

    Science.gov (United States)

    Tang, Chanjuan; Yu, Jianjun; Li, Xinying; Chi, Nan; Xiao, Jiangnan; Tian, Yumin; Zhang, Junwen

    2014-01-13

    We propose and experimentally demonstrate a full-duplex bi-directional transmission optical wireless-over fiber integration system at W-band (75-100 GHz) with the speed up to 15 Gb/s for both 95.4 GHz link and 88.6 GHz link for the first time. The generation of millimeter-wave (mm-wave) wireless signal is based on the photonic technique by heterodyne mixing of an optical quadrature-phase-shift-keying (QPSK) signal with a free-running light at different wavelength. After 20 km fiber transmission, up to 30 Gb/s mm-wave signal is delivered over 2 m wireless link, and then converted to the optical signal for another 20 km fiber transmission. At the wireless receiver, coherent detection and advanced digital signal processing (DSP) are introduced to improve receiver sensitivity and system performance. With the OSNR of 15 dB, the bit error ratios (BERs) for 10 Gb/s signal transmission at 95.4 GHz and 88.6 GHz are below the forward-error-correction (FEC) threshold of 3.8 × 10(-3) whether post filter is used or not, while the BER for 15 Gb/s QPSK signal employing post filter in the link of 95.4 GHz is 2.9 × 10(-3).

  8. 428-Gb/s single-channel coherent optical OFDM transmission over 960-km SSMF with constellation expansion and LDPC coding.

    Science.gov (United States)

    Yang, Qi; Al Amin, Abdullah; Chen, Xi; Ma, Yiran; Chen, Simin; Shieh, William

    2010-08-02

    High-order modulation formats and advanced error correcting codes (ECC) are two promising techniques for improving the performance of ultrahigh-speed optical transport networks. In this paper, we present record receiver sensitivity for 107 Gb/s CO-OFDM transmission via constellation expansion to 16-QAM and rate-1/2 LDPC coding. We also show the single-channel transmission of a 428-Gb/s CO-OFDM signal over 960-km standard-single-mode-fiber (SSMF) without Raman amplification.

  9. An extraordinary tabletop speed of light apparatus

    Science.gov (United States)

    Pegna, Guido

    2017-09-01

    A compact, low-cost, pre-aligned apparatus of the modulation type is described. The apparatus allows accurate determination of the speed of light in free propagation with an accuracy on the order of one part in 104. Due to the 433.92 MHz radio frequency (rf) modulation of its laser diode, determination of the speed of light is possible within a sub-meter measuring base and in small volumes (some cm3) of transparent solids or liquids. No oscilloscope is necessary, while the required function generators, power supplies, and optical components are incorporated into the design of the apparatus and its receiver can slide along the optical bench while maintaining alignment with the laser beam. Measurement of the velocity factor of coaxial cables is also easily performed. The apparatus detects the phase difference between the rf modulation of the laser diode by further modulating the rf signal with an audio frequency signal; the phase difference between these signals is then observed as the loudness of the audio signal. In this way, the positions at which the minima of the audio signal are found determine where the rf signals are completely out of phase. This phase detection method yields a much increased sensitivity with respect to the display of coincidence of two signals of questionable arrival time and somewhat distorted shape on an oscilloscope. The displaying technique is also particularly suitable for large audiences as well as in unattended exhibits in museums and science centers. In addition, the apparatus can be set up in less than one minute.

  10. GABAergic transmission and chloride equilibrium potential are not modulated by pyruvate in the developing optic tectum of Xenopus laevis tadpoles.

    Directory of Open Access Journals (Sweden)

    Arseny S Khakhalin

    Full Text Available In the developing mammalian brain, gamma-aminobutyric acid (GABA is thought to play an excitatory rather than an inhibitory role due to high levels of intracellular Cl(- in immature neurons. This idea, however, has been questioned by recent studies which suggest that glucose-based artificial cerebrospinal fluid (ACSF may be inadequate for experiments on immature and developing brains. These studies suggest that immature neurons may require alternative energy sources, such as lactate or pyruvate. Lack of these other energy sources is thought to result in artificially high intracellular Cl(- concentrations, and therefore a more depolarized GABA receptor (GABAR reversal potential. Since glucose metabolism can vary widely among different species, it is important to test the effects of these alternative energy sources on different experimental preparations. We tested whether pyruvate affects GABAergic transmission in isolated brains of developing wild type Xenopus tadpoles in vitro by recording the responsiveness of tectal neurons to optic nerve stimulation, and by measuring currents evoked by local GABA application in a gramicidin perforated patch configuration. We found that, in contrast with previously reported results, the reversal potential for GABAR-mediated currents does not change significantly between developmental stages 45 and 49. Partial substitution of glucose by pyruvate had only minor effects on both the GABA reversal potential, and the responsiveness of tectal neurons at stages 45 and 49. Total depletion of energy sources from the ACSF did not affect neural responsiveness. We also report a strong spatial gradient in GABA reversal potential, with immature cells adjacent to the lateral and caudal proliferative zones having more positive reversal potentials. We conclude that in this experimental preparation standard glucose-based ACSF is an appropriate extracellular media for in vitro experiments.

  11. Physical optics

    International Nuclear Information System (INIS)

    Kim Il Gon; Lee, Seong Su; Jang, Gi Wan

    2012-07-01

    This book indicates physical optics with properties and transmission of light, mathematical expression of wave like harmonic wave and cylindrical wave, electromagnetic theory and light, transmission of light with Fermat principle and Fresnel equation, geometrical optics I, geometrical optics II, optical instrument such as stops, glasses and camera, polarized light like double refraction by polarized light, interference, interference by multiple reflections, diffraction, solid optics, crystal optics such as Faraday rotation and Kerr effect and measurement of light. Each chapter has an exercise.

  12. Physical optics

    Energy Technology Data Exchange (ETDEWEB)

    Kim Il Gon; Lee, Seong Su; Jang, Gi Wan

    2012-07-15

    This book indicates physical optics with properties and transmission of light, mathematical expression of wave like harmonic wave and cylindrical wave, electromagnetic theory and light, transmission of light with Fermat principle and Fresnel equation, geometrical optics I, geometrical optics II, optical instrument such as stops, glasses and camera, polarized light like double refraction by polarized light, interference, interference by multiple reflections, diffraction, solid optics, crystal optics such as Faraday rotation and Kerr effect and measurement of light. Each chapter has an exercise.

  13. Determination of the sputter rate variation pattern of a silicon carbide target for radio frequency magnetron sputtering using optical transmission measurements

    International Nuclear Information System (INIS)

    Galvez de la Puente, G.; Guerra Torres, J.A.; Erlenbach, O.; Steidl, M.; Weingaertner, R.; De Zela, F.; Winnacker, A.

    2010-01-01

    We produce amorphous silicon carbide thin films (a-SiC) by radio frequency (rf) magnetron sputtering from SiC bulk target. We present the emission pattern of the rf magnetron with SiC target as a function of process parameters, like target sample distance, rf power, sputtering rate and process gas pressure. The emission pattern is determined by means of thickness distribution of the deposited a-SiC films obtained from optical transmission measurements using a slightly improved method of Swanepoel concerning the determination of construction of the envelopes in the interference pattern of the transmission spectra. A calibration curve is presented which allows the conversion of integrated transmission to film thickness. Holding constant a set of process parameters and only varying the target sample distance the emission pattern of the rf magnetron with SiC target was determined, which allowed us to predict the deposition rate distribution for a wide range of process parameters and target geometry. In addition, we have found that the transmission spectra of the a-SiC films change with time and saturate after approximately 10 days. Within this process no change in thickness is involved, so that the determination of thickness using transmission data is justified.

  14. 18 CFR 367.4340 - Account 434, Extraordinary income.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Account 434, Extraordinary income. 367.4340 Section 367.4340 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE PUBLIC UTILITY HOLDING COMPANY ACT OF 2005, FEDERAL POWER ACT AND NATURAL GAS ACT UNIFOR...

  15. 18 CFR 367.4350 - Account 435, Extraordinary deductions.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Account 435, Extraordinary deductions. 367.4350 Section 367.4350 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE PUBLIC UTILITY HOLDING COMPANY ACT OF 2005, FEDERAL POWER ACT AND NATURAL GAS ACT...

  16. 5 CFR 2635.503 - Extraordinary payments from former employers.

    Science.gov (United States)

    2010-01-01

    ... employers. 2635.503 Section 2635.503 Administrative Personnel OFFICE OF GOVERNMENT ETHICS GOVERNMENT ETHICS STANDARDS OF ETHICAL CONDUCT FOR EMPLOYEES OF THE EXECUTIVE BRANCH Impartiality in Performing Official Duties § 2635.503 Extraordinary payments from former employers. (a) Disqualification requirement. Except...

  17. Design and performance evaluation of an OpenFlow-based control plane for software-defined elastic optical networks with direct-detection optical OFDM (DDO-OFDM) transmission.

    Science.gov (United States)

    Liu, Lei; Peng, Wei-Ren; Casellas, Ramon; Tsuritani, Takehiro; Morita, Itsuro; Martínez, Ricardo; Muñoz, Raül; Yoo, S J B

    2014-01-13

    Optical Orthogonal Frequency Division Multiplexing (O-OFDM), which transmits high speed optical signals using multiple spectrally overlapped lower-speed subcarriers, is a promising candidate for supporting future elastic optical networks. In contrast to previous works which focus on Coherent Optical OFDM (CO-OFDM), in this paper, we consider the direct-detection optical OFDM (DDO-OFDM) as the transport technique, which leads to simpler hardware and software realizations, potentially offering a low-cost solution for elastic optical networks, especially in metro networks, and short or medium distance core networks. Based on this network scenario, we design and deploy a software-defined networking (SDN) control plane enabled by extending OpenFlow, detailing the network architecture, the routing and spectrum assignment algorithm, OpenFlow protocol extensions and the experimental validation. To the best of our knowledge, it is the first time that an OpenFlow-based control plane is reported and its performance is quantitatively measured in an elastic optical network with DDO-OFDM transmission.

  18. Implementation of orthogonal frequency division multiplexing (OFDM) and advanced signal processing for elastic optical networking in accordance with networking and transmission constraints

    Science.gov (United States)

    Johnson, Stanley

    An increasing adoption of digital signal processing (DSP) in optical fiber telecommunication has brought to the fore several interesting DSP enabled modulation formats. One such format is orthogonal frequency division multiplexing (OFDM), which has seen great success in wireless and wired RF applications, and is being actively investigated by several research groups for use in optical fiber telecom. In this dissertation, I present three implementations of OFDM for elastic optical networking and distributed network control. The first is a field programmable gate array (FPGA) based real-time implementation of a version of OFDM conventionally known as intensity modulation and direct detection (IMDD) OFDM. I experimentally demonstrate the ability of this transmission system to dynamically adjust bandwidth and modulation format to meet networking constraints in an automated manner. To the best of my knowledge, this is the first real-time software defined networking (SDN) based control of an OFDM system. In the second OFDM implementation, I experimentally demonstrate a novel OFDM transmission scheme that supports both direct detection and coherent detection receivers simultaneously using the same OFDM transmitter. This interchangeable receiver solution enables a trade-off between bit rate and equipment cost in network deployment and upgrades. I show that the proposed transmission scheme can provide a receiver sensitivity improvement of up to 1.73 dB as compared to IMDD OFDM. I also present two novel polarization analyzer based detection schemes, and study their performance using experiment and simulation. In the third implementation, I present an OFDM pilot-tone based scheme for distributed network control. The first instance of an SDN-based OFDM elastic optical network with pilot-tone assisted distributed control is demonstrated. An improvement in spectral efficiency and a fast reconfiguration time of 30 ms have been achieved in this experiment. Finally, I

  19. THE OPTICAL AND NEAR-INFRARED TRANSMISSION SPECTRUM OF THE SUPER-EARTH GJ 1214b: FURTHER EVIDENCE FOR A METAL-RICH ATMOSPHERE

    International Nuclear Information System (INIS)

    Bean, Jacob L.; Désert, Jean-Michel; Stalder, Brian; Berta, Zachory K.; Kabath, Petr; Seager, Sara; Miller-Ricci Kempton, Eliza; Homeier, Derek; Walsh, Shane; Seifahrt, Andreas

    2011-01-01

    We present an investigation of the transmission spectrum of the 6.5 M ⊕ planet GJ 1214b based on new ground-based observations of transits of the planet in the optical and near-infrared, and on previously published data. Observations with the VLT + FORS and Magellan + MMIRS using the technique of multi-object spectroscopy with wide slits yielded new measurements of the planet's transmission spectrum from 0.61 to 0.85 μm, and in the J, H, and K atmospheric windows. We also present a new measurement based on narrow-band photometry centered at 2.09 μm with the VLT + HAWKI. We combined these data with results from a reanalysis of previously published FORS data from 0.78 to 1.00 μm using an improved data reduction algorithm, and previously reported values based on Spitzer data at 3.6 and 4.5 μm. All of the data are consistent with a featureless transmission spectrum for the planet. Our K-band data are inconsistent with the detection of spectral features at these wavelengths reported by Croll and collaborators at the level of 4.1σ. The planet's atmosphere must either have at least 70% H 2 O by mass or optically thick high-altitude clouds or haze to be consistent with the data.

  20. Oxygen surface exchange kinetics measurement by simultaneous optical transmission relaxation and impedance spectroscopy: Sr(Ti,Fe)O3-x thin film case study.

    Science.gov (United States)

    Perry, Nicola H; Kim, Jae Jin; Tuller, Harry L

    2018-01-01

    We compare approaches to measure oxygen surface exchange kinetics, by simultaneous optical transmission relaxation (OTR) and AC-impedance spectroscopy (AC-IS), on the same mixed conducting SrTi 0.65 Fe 0.35 O 3-x film. Surface exchange coefficients were evaluated as a function of oxygen activity in the film, controlled by gas partial pressure and/or DC bias applied across the ionically conducting yttria-stabilized zirconia substrate. Changes in measured light transmission through the film over time (relaxations) resulted from optical absorption changes in the film corresponding to changes in its oxygen and oxidized Fe (~Fe 4+ ) concentrations; such relaxation profiles were successfully described by the equation for surface exchange-limited kinetics appropriate for the film geometry. The k chem values obtained by OTR were significantly lower than the AC-IS derived k chem values and k q values multiplied by the thermodynamic factor (bulk or thin film), suggesting a possible enhancement in k by the metal current collectors (Pt, Au). Long-term degradation in k chem and k q values obtained by AC-IS was also attributed to deterioration of the porous Pt current collector, while no significant degradation was observed in the optically derived k chem values. The results suggest that, while the current collector might influence measurements by AC-IS, the OTR method offers a continuous, in situ , and contact-free method to measure oxygen exchange kinetics at the native surfaces of thin films.

  1. Oxygen surface exchange kinetics measurement by simultaneous optical transmission relaxation and impedance spectroscopy: Sr(Ti,Fe)O3-x thin film case study

    Science.gov (United States)

    Perry, Nicola H.; Kim, Jae Jin; Tuller, Harry L.

    2018-01-01

    Abstract We compare approaches to measure oxygen surface exchange kinetics, by simultaneous optical transmission relaxation (OTR) and AC-impedance spectroscopy (AC-IS), on the same mixed conducting SrTi0.65Fe0.35O3-x film. Surface exchange coefficients were evaluated as a function of oxygen activity in the film, controlled by gas partial pressure and/or DC bias applied across the ionically conducting yttria-stabilized zirconia substrate. Changes in measured light transmission through the film over time (relaxations) resulted from optical absorption changes in the film corresponding to changes in its oxygen and oxidized Fe (~Fe4+) concentrations; such relaxation profiles were successfully described by the equation for surface exchange-limited kinetics appropriate for the film geometry. The kchem values obtained by OTR were significantly lower than the AC-IS derived kchem values and kq values multiplied by the thermodynamic factor (bulk or thin film), suggesting a possible enhancement in k by the metal current collectors (Pt, Au). Long-term degradation in kchem and kq values obtained by AC-IS was also attributed to deterioration of the porous Pt current collector, while no significant degradation was observed in the optically derived kchem values. The results suggest that, while the current collector might influence measurements by AC-IS, the OTR method offers a continuous, in situ, and contact-free method to measure oxygen exchange kinetics at the native surfaces of thin films. PMID:29511391

  2. All-Optical envelope detection and fiber transmission of wireless signals by external injection of a DFB laser

    DEFF Research Database (Denmark)

    Prince, Kamau; Tafur Monroy, Idelfonso

    2008-01-01

    We outline a novel method for all-optical envelope detection of wireless signals by exploiting cross-gain modulation effects in a distributed feedback laser operating with optical injection. We successfully demonstrate envelope detection of a 20-GHz carrier amplitude-shift-keying modulated signal...

  3. Identification of persons by means of the Fourier spectra of the optical transmission binary models of the human irises

    Czech Academy of Sciences Publication Activity Database

    Muroň, A.; Koiš, P.; Pospíšil, Jaroslav

    2001-01-01

    Roč. 192, - (2001), s. 161-167 ISSN 0030-4018 Institutional research plan: CEZ:AV0Z1010921 Keywords : human iris * coherent optical Fourier transform * identification of persons Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.354, year: 2001

  4. A novel construction method of QC-LDPC codes based on the subgroup of the finite field multiplicative group for optical transmission systems

    Science.gov (United States)

    Yuan, Jian-guo; Zhou, Guang-xiang; Gao, Wen-chun; Wang, Yong; Lin, Jin-zhao; Pang, Yu

    2016-01-01

    According to the requirements of the increasing development for optical transmission systems, a novel construction method of quasi-cyclic low-density parity-check (QC-LDPC) codes based on the subgroup of the finite field multiplicative group is proposed. Furthermore, this construction method can effectively avoid the girth-4 phenomena and has the advantages such as simpler construction, easier implementation, lower encoding/decoding complexity, better girth properties and more flexible adjustment for the code length and code rate. The simulation results show that the error correction performance of the QC-LDPC(3 780,3 540) code with the code rate of 93.7% constructed by this proposed method is excellent, its net coding gain is respectively 0.3 dB, 0.55 dB, 1.4 dB and 1.98 dB higher than those of the QC-LDPC(5 334,4 962) code constructed by the method based on the inverse element characteristics in the finite field multiplicative group, the SCG-LDPC(3 969,3 720) code constructed by the systematically constructed Gallager (SCG) random construction method, the LDPC(32 640,30 592) code in ITU-T G.975.1 and the classic RS(255,239) code which is widely used in optical transmission systems in ITU-T G.975 at the bit error rate ( BER) of 10-7. Therefore, the constructed QC-LDPC(3 780,3 540) code is more suitable for optical transmission systems.

  5. Parametric decay of an extraordinary electromagnetic wave in relativistic plasma

    Energy Technology Data Exchange (ETDEWEB)

    Dorofeenko, V. G. [Institute for Advanced Studies (Austria); Krasovitskiy, V. B., E-mail: krasovit@mail.ru [Keldysh Institute of Applied Mathematics (Russian Federation); Turikov, V. A. [Peoples’ Friendship University of Russia (Russian Federation)

    2015-03-15

    Parametric instability of an extraordinary electromagnetic wave in plasma preheated to a relativistic temperature is considered. A set of self-similar nonlinear differential equations taking into account the electron “thermal” mass is derived and investigated. Small perturbations of the parameters of the heated plasma are analyzed in the linear approximation by using the dispersion relation determining the phase velocities of the fast and slow extraordinary waves. In contrast to cold plasma, the evanescence zone in the frequency range above the electron upper hybrid frequency vanishes and the asymptotes of both branches converge. Theoretical analysis of the set of nonlinear equations shows that the growth rate of decay instability increases with increasing initial temperature of plasma electrons. This result is qualitatively confirmed by numerical simulations of plasma heating by a laser pulse injected from vacuum.

  6. Extraordinary Hall-effect in colloidal magnetic nanoparticle films

    Energy Technology Data Exchange (ETDEWEB)

    Ben Gur, Leah; Tirosh, Einat [School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801 (Israel); Segal, Amir [School of Physics, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801 (Israel); Markovich, Gil, E-mail: gilmar@post.tau.ac.il [School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801 (Israel); Gerber, Alexander, E-mail: gerber@post.tau.ac.il [School of Physics, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801 (Israel)

    2017-03-15

    Colloidal nickel nanoparticles (NPs) coated with polyvinylpyrrolidone (PVP) were synthesized. The nanoparticle dispersions were deposited on substrates and dried under mild heating to form conductive films. The films exhibited very small coercivity, nearly metallic conductivity, and a significant extraordinary Hall effect signal. This method could be useful for preparing simple, printed magnetic field sensors with the advantage of relatively high sensitivity around zero magnetic field, in contrast to magnetoresistive sensors, which have maximal field sensitivity away from zero magnetic field. - Highlights: • Ni nanoparticle ink capable of forming conductive films on drying. • The Ni nanoparticle films exhibit significant extraordinary Hall effect. • This system could be used for preparing printed magnetic field sensors integrated in 3D printed structures.

  7. Correlation of ''twins'' observed by optical microscopy and transmission electron microscopy in YBa2Cu3O7/sub -//sub x/ superconductors

    International Nuclear Information System (INIS)

    Hoff, H.A.; Singh, A.K.; Pande, C.S.

    1988-01-01

    By using transmission electron microscopy and optical microscopy on the same specimens, the patterns of light- and dark-contrast lines seen in reflected polarized light were shown to be an interference pattern due to the variable spacing of suboptical microtwins. These microtwins are mostly [110] reflection twins. The [110] twinning was observed to be cyclic and occasionally pseudotetragonal because of the progressive cycling of contact twin domains. Within a domain, and occasionally in a whole grain, the [110] reflection twins occurred as polysynthetic lamellae. The morphology of the domain structure can be explained from the theory of martensitic transformation

  8. The League of Extraordinary Gentlemen as (Literary) History

    DEFF Research Database (Denmark)

    Backe, Hans-Joachim

    2017-01-01

    Alan Moore and Kevin O’Neill’s series The League of Extraordinary Gentlemen, published since 1999, depicts a world which is populated by characters of fiction, from Allan Quatermain and Captain Nemo to James Bond and Harry Potter. The result is not only a meta-fictional bricolage of cornerstones ...... about the feedback between history and literary history through the lens of comics and the medium’s own development....

  9. 20040217 NATO Advanced Research Workshop on Quasi-Optical Control of Intense Microwave Transmission Nizhny Novgorod, Russia 17 - 20 Feb 2004 2004 novgorod20040217 20040220

    CERN Document Server

    Hirshfield, Jay L

    2005-01-01

    This volume assembles the texts of presentations given at the NATO-sponsored Advanced Research Workshop on Quasi-Optical Transmission of High-Power Microwaves, held in Nizhny Novgorod, Russia in February 2004. The presentations bridge a wide range of technical areas, but share common tools of analysis and design. Applications of quasi-optics extend to the use of high-power microwaves—including millimeter-waves— for radar and communications (especially deep space millimeter-wave systems, space debris detection radar, and radar for the detection of small targets moving over heavy clutter); particle accelerators (especially for a future high-acceleration-gradient electron-positron collider); plasma research (especially for controlled nuclear fusion and waste decontamination); and material processing (in particular, ceramic sintering with millimeter-waves, and the coating of metal surfaces with protective dielectric films.). Scientists and engineers working in any of these areas should benefit significantly f...

  10. 4.8 Gbit/s 16-QAM-OFDM transmission based on compact 450-nm laser for underwater wireless optical communication

    KAUST Repository

    Oubei, Hassan M.; Duran, Jose R.; Janjua, Bilal; Wang, Huai-Yung; Tsai, Cheng-Ting; Chi, Yu-Cheih; Ng, Tien Khee; Kuo, Hao-Chung; He, Jr-Hau; Alouini, Mohamed-Slim; Lin, Gong-Ru; Ooi, Boon S.

    2015-01-01

    We experimentally demonstrate an underwater wireless optical communications (UWOC) employing 450-nm TO-9 packaged and fiberpigtailed laser diode (LD) directly encoded with an orthogonal frequency division multiplexed quadrature amplitude modulation (QAM-OFDM) data. A record data rate of up to 4.8 Gbit/s over 5.4-m transmission distance is achieved. By encoding the full 1.2-GHz bandwidth of the 450-nm LD with a 16-QAM-OFDM data, an error vector magnitude (EVM) of 16.5%, a signal-to-noise ratio (SNR) of 15.63 dB and a bit error rate (BER) of 2.6 × 10-3, well pass the forward error correction (FEC) criterion, were obtained. © 2015 Optical Society of America.

  11. 4.8 Gbit/s 16-QAM-OFDM transmission based on compact 450-nm laser for underwater wireless optical communication

    KAUST Repository

    Oubei, Hassan M.

    2015-08-26

    We experimentally demonstrate an underwater wireless optical communications (UWOC) employing 450-nm TO-9 packaged and fiberpigtailed laser diode (LD) directly encoded with an orthogonal frequency division multiplexed quadrature amplitude modulation (QAM-OFDM) data. A record data rate of up to 4.8 Gbit/s over 5.4-m transmission distance is achieved. By encoding the full 1.2-GHz bandwidth of the 450-nm LD with a 16-QAM-OFDM data, an error vector magnitude (EVM) of 16.5%, a signal-to-noise ratio (SNR) of 15.63 dB and a bit error rate (BER) of 2.6 × 10-3, well pass the forward error correction (FEC) criterion, were obtained. © 2015 Optical Society of America.

  12. Methodological Approach Into Researching Traffic Under Extraordinary Security Circumstances

    Directory of Open Access Journals (Sweden)

    Peter-Anthony Ercegovac

    2008-09-01

    Full Text Available The complexity of researching traffic under extraordinaryconditions in order to implement a more efficient and functionaltraffic management strategy under both normal and irregularconditions- as well as the grey zone of when the changefrom normal into extraordinary traffic conditions actually occur-provides the researcher with numerous methodologicalproblems.Starting from the viewpoint that the field of traffic scienceneeds an increase into the capacity of research into traffic underextraordinary conditions we have chosen to define withinthis article a specific methodological approach that undertakesa study into the exposure, menace, threat and risk faced by trafficsystems under extraordinary conditions through utilisingmethods utilised by the military that allow for the possible resolutionof such problems through compatible testing of both simulatedand real life conditions that such systems may face.In searching for possible applicable solutions to such demandingparametres we believe that the use of concrete informationin real time and real space in order to bring about amore efficient functioning of traffic under extraordinary conditionscan be achieved through the use of the analytical capacityof traffic systems information gathering attained through theusage of Uninhabited Flying Vehicles (UFVs in monitoringroad, rail and maritime traffic and transport.

  13. Optics

    CERN Document Server

    Mathieu, Jean Paul

    1975-01-01

    Optics, Parts 1 and 2 covers electromagnetic optics and quantum optics. The first part of the book examines the various of the important properties common to all electromagnetic radiation. This part also studies electromagnetic waves; electromagnetic optics of transparent isotropic and anisotropic media; diffraction; and two-wave and multi-wave interference. The polarization states of light, the velocity of light, and the special theory of relativity are also examined in this part. The second part is devoted to quantum optics, specifically discussing the classical molecular theory of optical p

  14. Observation of superconducting fluxons by transmission electron microscopy: A Fourier space approach to calculate the electron optical phase shifts and images

    International Nuclear Information System (INIS)

    Beleggia, M.; Pozzi, G.

    2001-01-01

    An approach is presented for the calculation of the electron optical phase shift experienced by high-energy electrons in a transmission electron microscope, when they interact with the magnetic field associated with superconducting fluxons in a thin specimen tilted with respect to the beam. It is shown that by decomposing the vector potential in its Fourier components and by calculating the phase shift of each component separately, it is possible to obtain the Fourier transform of the electron optical phase shift, which can be inverted either analytically or numerically. It will be shown how this method can be used to recover the result, previously obtained by the real-space approach, relative to the case of a straight flux tube perpendicular to the specimen surfaces. Then the method is applied to the case of a London fluxon in a thin film, where the bending and the broadening of the magnetic-field lines due to the finite specimen thickness are now correctly taken into account and not treated approximately by means of a parabolic fit. Finally, it will be shown how simple models for the pancake structure of the fluxon can be analyzed within this framework and the main features of electron transmission images predicted

  15. The Way of Reducing Current Values in Optical Ground Wires at Asymmetrical Faults on Overhead Transmission Lines

    Directory of Open Access Journals (Sweden)

    Egamnazarov Georgiy

    2016-12-01

    Full Text Available Given the fact that the installing costs of an optical ground wire on overhead lines directly depend on its cross-section, which in turn depends on the level of fault current it should withstand, in order to reduce these current values in the optical ground wire, I suggested performing its isolated descents from the end towers of the line with its transition to an optical cable. The research was carried out on the example of a 500 kV overhead line in the National Electric Power Grid. The Method of Symmetrical Components for calculating asymmetrical fault currents was not used; therefore, calculations were carried out on the base of presenting the line as a multi-wire system for the considered case as a five-wire system (optical ground wire, steel ground wire, and three phase wires. Such approach allows taking into account the initial asymmetry of the line parameters and modeling any kind of asymmetrical faults. The analyses of calculated results were performed. The conclusive evidence that the optical ground wire isolated descents from the end towers of the line give the possibility of reducing the level of maximal fault current distribution values in it and therefore its cross section, is presented.

  16. Optical 16-QAM-52-OFDM transmission at 4 Gbit/s by directly modulating a coherently injection-locked colorless laser diode.

    Science.gov (United States)

    Chi, Yu-Chieh; Li, Yi-Cheng; Wang, Huai-Yung; Peng, Peng-Chun; Lu, Hai-Han; Lin, Gong-Ru

    2012-08-27

    Coherently injection-locked and directly modulated weak-resonant-cavity laser diode (WRC-FPLD) for back-to-back optical 16-quadrature-amplitude-modulation (QAM) and 52-subcarrier orthogonal frequency division multiplexing (OFDM) transmission with maximum bit rate up to 4 Gbit/s at carrier frequency of 2.5 GHz is demonstrated. The WRC-FPLD transmitter source is a specific design with very weak-resonant longitudinal modes to preserve its broadband gain spectral characteristics for serving as a colorless WDM-PON transmitter. Under coherent injection-locking, the relative-intensity noise (RIN) of the injection-locked WRC-FPLD can be suppressed to ?105 dBc/Hz and the error vector magnitude of the received optical OFDM data is greatly reduced with the amplitude error suppressed down 5.5%. Such a coherently injection-locked single-mode WRC-FPLD can perform both the back-to-back and the 25-km-SMF 16-QAM-52-OFDM transmissions with a symbol rate of 20-MSa/s in each OFDM subcarrier. After coherent injection locking, the BER of the back-to-back transmitted 16-QAM-52-OFDM data is reduced to 2.5 × 10(-5) at receiving power of ?10 dBm. After propagating along a 25-km-long SMF, a receiving power sensitivity of ?7.5 dBm is required to obtain a lowest BER of 2.5 × 10(-5), and a power penalty of 2.7 dB is observed when comparing with the back-to-back transmission.

  17. Dual-polarization multi-band optical OFDM transmission and transceiver limitations for up to 500 Gb/s uncompensated long-haul links.

    Science.gov (United States)

    Giacoumidis, E; Jarajreh, M A; Sygletos, S; Le, S T; Farjady, F; Tsokanos, A; Hamié, A; Pincemin, E; Jaouën, Y; Ellis, A D; Doran, N J

    2014-05-05

    A number of critical issues for dual-polarization single- and multi-band optical orthogonal-frequency division multiplexing (DP-SB/MB-OFDM) signals are analyzed in dispersion compensation fiber (DCF)-free long-haul links. For the first time, different DP crosstalk removal techniques are compared, the maximum transmission-reach is investigated, and the impact of subcarrier number and high-level modulation formats are explored thoroughly. It is shown, for a bit-error-rate (BER) of 10(-3), 2000 km of quaternary phase-shift keying (QPSK) DP-MB-OFDM transmission is feasible. At high launched optical powers (LOP), maximum-likelihood decoding can extend the LOP of 40 Gb/s QPSK DP-SB-OFDM at 2000 km by 1.5 dB compared to zero-forcing. For a 100 Gb/s DP-MB-OFDM system, a high number of subcarriers contribute to improved BER but at the cost of digital signal processing computational complexity, whilst by adapting the cyclic prefix length the BER can be improved for a low number of subcarriers. In addition, when 16-quadrature amplitude modulation (16QAM) is employed the digital-to-analogue/analogue-to-digital converter (DAC/ADC) bandwidth is relaxed with a degraded BER; while the 'circular' 8QAM is slightly superior to its 'rectangular' form. Finally, the transmission of wavelength-division multiplexing DP-MB-OFDM and single-carrier DP-QPSK is experimentally compared for up to 500 Gb/s showing great potential and similar performance at 1000 km DCF-free G.652 line.

  18. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  19. Understanding Extraordinary Architectural Experiences through Content Analysis of Written Narratives

    Directory of Open Access Journals (Sweden)

    Brandon Richard Ro

    2015-12-01

    Full Text Available This study a identifies how people describe, characterize, and communicate in written form Extraordinary Architectural Experiences (EAE, and b expands the traditional qualitative approach to architectural phenomenology by demonstrating a quantitative method to analyze written narratives. Specifically, this study reports on the content analysis of 718 personal accounts of EAEs. Using a deductive, ‘theory-driven’ approach, these narratives were read, coded, and statistically analyzed to identify storyline structure, convincing power, and the relationship between subjective and objective experiential qualities used in the story-telling process. Statistical intercoder agreement tests were conducted to verify the reliability of the interpretations to approach the hard problem of “extraordinary aesthetics” in architecture empirically. The results of this study confirm the aesthetic nature of EAE narratives (and of told experiences by showing their higher dependence on external objective content (e.g., a building’s features and location rather than its internal subjective counterpart (e.g., emotions and sensations, which makes them more outwardly focused. The strong interrelationships and intercoder agreement between the thematic realms provide a unique aesthetic construct revealing EAE narratives as memorable, embodied, emotional events mapped by the externally focused content of place, social setting, time, and building features. A majority of EAE narratives were found to possess plot-structure along with significant relationships to objective-subjective content that further grounded their storylines. This study concludes that content analysis provides not only a valid method to understand written narratives about extraordinary architectural experiences quantitatively, but also a view as to how to map the unique nature of aesthetic phenomenology empirically.

  20. A 7-13 GHz low-noise tuned optical front-end amplifier for heterodyne transmission system application

    DEFF Research Database (Denmark)

    Ebskamp, Frank; Schiellerup, Gert; Høgdal, Morten

    1991-01-01

    The authors present a 7-13 GHz low-noise bandpass tuned optical front-end amplifier, showing 46±1 dBΩ transimpedance, and a noise spectral density of about 12 pA/√Hz. This is the first time such a flat response and such low noise were obtained simultaneously at these frequencies, without any...

  1. 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.

  2. Clock-distribution with instantaneous synchronisation for 160 Gbit/s optical time-domain multiplexed packet transmission

    NARCIS (Netherlands)

    Gomez-Agis, F.; Calabretta, N.; Albores Mejia, A.; Dorren, H.J.S.

    2010-01-01

    We demonstrate for the first time, to our knowledge, a clock-distribution method for ultra-high-speed optical time-domain multiplexed systems data packets that provides instantaneous synchronization, fast locking/unlocking times, and a highly stable bursty clock, enabling error-free operation of 160

  3. Characterization of CuCl quantum dots grown in NaCl single crystals via optical measurements, X-ray diffraction, and transmission electron microscopy

    Science.gov (United States)

    Miyajima, Kensuke; Akatsu, Tatsuro; Itoh, Ken

    2018-05-01

    We evaluated the crystal size, shape, and alignment of the lattice planes of CuCl quantum dots (QDs) embedded in NaCl single crystals by optical measurements, X-ray diffraction (XRD) patterns, and transmission electron microscopy (TEM). We obtained, for the first time, an XRD pattern and TEM images for CuCl QDs in NaCl crystals. The XRD pattern showed that the lattice planes of the CuCl QDs were parallel to those of the NaCl crystals. In addition, the size of the QDs was estimated from the diffraction width. It was apparent from the TEM images that almost all CuCl QDs were polygonal, although some cubic QDs were present. The mean size and size distribution of the QDs were also obtained. The dot size obtained from optical measurements, XRD, and TEM image were almost consistent. Our new findings can help to reveal the growth mechanism of semiconductor QDs embedded in a crystallite matrix. In addition, this work will play an important role in progressing the study of optical phenomena originating from assembled semiconductor QDs.

  4. Stresses on nuclear power plant buildings by extraordinary events

    International Nuclear Information System (INIS)

    Woelfel, E.

    1977-01-01

    Nuclear power plant buildings must be functional to such an extend that even after the occurence of extraordinary events (earthquake, airoplane crash, gas cloud explosion), the reactor can be safety shut off, in order to avoid danger from the nuclear power plant. Evidence for this can only be given by calculations which shall meet the following requirements: The calculation results shall be safe and reliable. The calculation effort shall match the realizable accuracy. The calculation shall lead to an economical determination. An example of ascertainment of nuclear power plants in regard to earthquakes, shows the difficulties standing against a fulfillment of these requirements. (orig.) [de

  5. Low-peak-to-average power ratio and low-complexity asymmetrically clipped optical orthogonal frequency-division multiplexing uplink transmission scheme for long-reach passive optical network.

    Science.gov (United States)

    Zhou, Ji; Qiao, Yaojun

    2015-09-01

    In this Letter, we propose a discrete Hartley transform (DHT)-spread asymmetrically clipped optical orthogonal frequency-division multiplexing (DHT-S-ACO-OFDM) uplink transmission scheme in which the multiplexing/demultiplexing process also uses the DHT algorithm. By designing a simple encoding structure, the computational complexity of the transmitter can be reduced from O(Nlog(2)(N)) to O(N). At the probability of 10(-3), the peak-to-average power ratio (PAPR) of 2-ary pulse amplitude modulation (2-PAM)-modulated DHT-S-ACO-OFDM is approximately 9.7 dB lower than that of 2-PAM-modulated conventional ACO-OFDM. To verify the feasibility of the proposed scheme, a 4-Gbit/s DHT-S-ACO-OFDM uplink transmission scheme with a 1∶64 way split has been experimentally implemented using 100-km standard single-mode fiber (SSMF) for a long-reach passive optical network (LR-PON).

  6. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  7. Optical transmission through aerosol deposits on diffusely reflective filters: a method for measuring the absorbing component of aerosol particles

    International Nuclear Information System (INIS)

    Rosen, H.; Novakov, T.

    1983-01-01

    It is unclear why the backscattered radiation from nonabsorbing particles should not make a significant contribution to the optical attenuation measurement. This is especially true where the absorbing component represents only a very small fraction of the aerosol mass. In this Letter we present a simple theoretical model which accounts for all these observations and points out the critical role of the filter substrate as an almost perfect diffuse reflector in the technique

  8. Modeling of solar transmission through multilayer glazing facade using shading blinds with arbitrary geometrical and surface optical properties

    International Nuclear Information System (INIS)

    Luo, Yongqiang; Zhang, Ling; Wu, Jing; Wang, Xiliang; Liu, Zhongbing; Wu, Zhenghong

    2017-01-01

    A system model that can accurately simulate the instantaneous solar transmittance through multilayer glazing façade (MGF) and shading device can provide a solid foundation for the thermal and daylighting performance calculation of MGF as well as indoor visual comfort evaluation. Traditional optical models for venetian blind and glazing façade meet with their limitations to analyze new prototype of shading blind like photovoltaic (PV) blind which has quite different surface optical properties compared with conventional venetian blind. The present study proposed a new system model for MGF using shading blind with arbitrary geometrical and optical features which is suitable for a wide range of applications. Three major calculation types for modeling of shading blinds cover all the possible situations in application. Guess Integer-Valued Function is adopted for delivering a general description on direct radiation transport. The direct-direct, direct-diffuse and diffuse-diffuse radiation transports are separately considered. A series of experiments were carried out to validate the model under various parameter settings and different weather conditions. Parametric study revealed some new findings in the evaluations of influence of ambient radiation situations, geometrical and optical features of blind space on both solar transmittance and solar absorption by blind layer. - Highlights: • Solar transport through glazing façades with PV blind with arbitrary geometry is simulated. • Ray-tracing and radiosity method are coupled in calculation. • Guess Integer-Valued Function is used in calculation of direct radiation transport. • Experiment and simulated data are compared for model validation. • Parametric study is conducted for evaluating the impact of different factors on the system.

  9. Transmission and group-delay characterization of coupled resonator optical waveguides apodized through the longitudinal offset technique.

    Science.gov (United States)

    Doménech, J D; Muñoz, P; Capmany, J

    2011-01-15

    In this Letter, the amplitude and group delay characteristics of coupled resonator optical waveguides apodized through the longitudinal offset technique are presented. The devices have been fabricated in silicon-on-insulator technology employing deep ultraviolet lithography. The structures analyzed consisted of three racetracks resonators uniform (nonapodized) and apodized with the aforementioned technique, showing a delay of 5 ± 3 ps and 4 ± 0.5 ps over 1.6 and 1.4 nm bandwidths, respectively.

  10. Age structure changes and extraordinary lifespan in wild medfly populations.

    Science.gov (United States)

    Carey, James R; Papadopoulos, Nikos T; Müller, Hans-Georg; Katsoyannos, Byron I; Kouloussis, Nikos A; Wang, Jane-Ling; Wachter, Kenneth; Yu, Wei; Liedo, Pablo

    2008-06-01

    The main purpose of this study was to test the hypotheses that major changes in age structure occur in wild populations of the Mediterranean fruit fly (medfly) and that a substantial fraction of individuals survive to middle age and beyond (> 3-4 weeks). We thus brought reference life tables and deconvolution models to bear on medfly mortality data gathered from a 3-year study of field-captured individuals that were monitored in the laboratory. The average time-to-death of captured females differed between sampling dates by 23.9, 22.7, and 37.0 days in the 2003, 2004, and 2005 field seasons, respectively. These shifts in average times-to-death provided evidence of changes in population age structure. Estimates indicated that middle-aged medflies (> 30 days) were common in the population. A surprise in the study was the extraordinary longevity observed in field-captured medflies. For example, 19 captured females but no reference females survived in the laboratory for 140 days or more, and 6 captured but no reference males survived in the laboratory for 170 days or more. This paper advances the study of aging in the wild by introducing a new method for estimating age structure in insect populations, demonstrating that major changes in age structure occur in field populations of insects, showing that middle-aged individuals are common in the wild, and revealing the extraordinary lifespans of wild-caught individuals due to their early life experience in the field.

  11. Ultrafast optical control of terahertz surface plasmons in subwavelength hole-arrays at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Azad, Abul Kalam [Los Alamos National Laboratory; Chen, Hou - Tong [Los Alamos National Laboratory; Taylor, Antoinette [Los Alamos National Laboratory; O' Hara, John [Los Alamos National Laboratory

    2010-12-10

    Extraordinary optical transmission through subwavelength metallic hole-arrays has been an active research area since its first demonstration. The frequency selective resonance properties of subwavelength metallic hole arrays, generally known as surface plasmon polaritons, have potential use in functional plasmonic devices such as filters, modulators, switches, etc. Such plasmonic devices are also very promising for future terahertz applications. Ultrafast switching or modulation of the resonant behavior of the 2-D metallic arrays in terahertz frequencies is of particular interest for high speed communication and sensing applications. In this paper, we demonstrate optical control of surface plasmon enhanced resonant terahertz transmission in two-dimensional subwavelength metallic hole arrays fabricated on gallium arsenide based substrates. Optically pumping the arrays creates a conductive layer in the substrate reducing the terahertz transmission amplitude of both the resonant mode and the direct transmission. Under low optical fluence, the terahertz transmission is more greatly affected by resonance damping than by propagation loss in the substrate. An ErAs:GaAs nanoisland superlattice substrate is shown to allow ultrafast control with a switching recovery time of {approx}10 ps. We also present resonant terahertz transmission in a hybrid plasmonic film comprised of an integrated array of subwavelength metallic islands and semiconductor holes. A large dynamic transition between a dipolar localized surface plasmon mode and a surface plasmon resonance near 0.8 THz is observed under near infrared optical excitation. The reversal in transmission amplitude from a stopband to a passband and up to {pi}/2 phase shift achieved in the hybrid plasmonic film make it promising in large dynamic phase modulation, optical changeover switching, and active terahertz plasmonics.

  12. Enhanced optical transmission through a star-shaped bull's eye at dual resonant-bands in UV and the visible spectral range.

    Science.gov (United States)

    Nazari, Tavakol; Khazaeinezhad, Reza; Jung, Woohyun; Joo, Boram; Kong, Byung-Joo; Oh, Kyunghwan

    2015-07-13

    Dual resonant bands in UV and the visible range were simultaneously observed in the enhanced optical transmission (EOT) through star-shaped plasmonic structures. EOTs through four types of polygonal bull's eyes with a star aperture surrounded by the concentric star grooves were analyzed and compared for 3, 4, 5, and 6 corners, using finite difference time domain (FDTD) method. In contrast to plasmonic resonances in the visible range, the UV-band resonance intensity was found to scale with the number of corners, which is related with higher order multipole interactions. Spectral positions and relative intensities of the dual resonances were analyzed parametrically to find optimal conditions to maximize EOT in UV-visible dual bands.

  13. Capacity-Approaching Modulation Formats for Optical Transmission Systems: Signal shaping and advanced de/muxing for efficient resource exploitation

    DEFF Research Database (Denmark)

    Estaran Tolosa, Jose Manuel

    Aiming for efficient fiber-optic data transport, this thesis addresses three scenario-specific modulation and/or multiplexing techniques which, leveraging digital signal processing, can further exploit the available resources.The considered environments are: (i) (ultra) long-haul networks, where we...... focus on improving the receiver sensitivity; (ii) metropolitan area networks, where the target is providing spectral and rate adaptability with fine granularity and easy reconfigurability; and (iii) short-haul networks, where facilitating more affordable throughput scaling is pursued. Functioning...

  14. Optical transmission testing based on asynchronous sampling techniques: images analysis containing chromatic dispersion using convolutional neural network

    Science.gov (United States)

    Mrozek, T.; Perlicki, K.; Tajmajer, T.; Wasilewski, P.

    2017-08-01

    The article presents an image analysis method, obtained from an asynchronous delay tap sampling (ADTS) technique, which is used for simultaneous monitoring of various impairments occurring in the physical layer of the optical network. The ADTS method enables the visualization of the optical signal in the form of characteristics (so called phase portraits) that change their shape under the influence of impairments such as chromatic dispersion, polarization mode dispersion and ASE noise. Using this method, a simulation model was built with OptSim 4.0. After the simulation study, data were obtained in the form of images that were further analyzed using the convolutional neural network algorithm. The main goal of the study was to train a convolutional neural network to recognize the selected impairment (distortion); then to test its accuracy and estimate the impairment for the selected set of test images. The input data consisted of processed binary images in the form of two-dimensional matrices, with the position of the pixel. This article focuses only on the analysis of images containing chromatic dispersion.

  15. Heterodyne frequency-domain multispectral diffuse optical tomography of breast cancer in the parallel-plane transmission geometry

    Energy Technology Data Exchange (ETDEWEB)

    Ban, H. Y.; Kavuri, V. C., E-mail: venk@physics.upenn.edu; Cochran, J. M.; Pathak, S.; Chung, S. H.; Yodh, A. G. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Schweiger, M.; Arridge, S. R. [Department of Computer Science, University College London, London WC1E 7JE (United Kingdom); Xie, L. [Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Busch, D. R. [Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 (United States); Katrašnik, J. [Faculty of Electrical Engineering, University of Ljubljana, Ljubljana 1000 (Slovenia); Lee, K. [Daegu Gyeongbuk Institute of Science and Technology, Daegu 711-813 (Korea, Republic of); Choe, R. [Department of Biomedical Engineering, University of Rochester, Rochester, New York 14642 (United States); Czerniecki, B. J. [Department of Surgery, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2016-07-15

    Purpose: The authors introduce a state-of-the-art all-optical clinical diffuse optical tomography (DOT) imaging instrument which collects spatially dense, multispectral, frequency-domain breast data in the parallel-plate geometry. Methods: The instrument utilizes a CCD-based heterodyne detection scheme that permits massively parallel detection of diffuse photon density wave amplitude and phase for a large number of source–detector pairs (10{sup 6}). The stand-alone clinical DOT instrument thus offers high spatial resolution with reduced crosstalk between absorption and scattering. Other novel features include a fringe profilometry system for breast boundary segmentation, real-time data normalization, and a patient bed design which permits both axial and sagittal breast measurements. Results: The authors validated the instrument using tissue simulating phantoms with two different chromophore-containing targets and one scattering target. The authors also demonstrated the instrument in a case study breast cancer patient; the reconstructed 3D image of endogenous chromophores and scattering gave tumor localization in agreement with MRI. Conclusions: Imaging with a novel parallel-plate DOT breast imager that employs highly parallel, high-resolution CCD detection in the frequency-domain was demonstrated.

  16. High-Speed Semiconductor Vertical-Cavity Surface-Emitting Lasers for Optical Data-Transmission Systems (Review)

    Science.gov (United States)

    Blokhin, S. A.; Maleev, N. A.; Bobrov, M. A.; Kuzmenkov, A. G.; Sakharov, A. V.; Ustinov, V. M.

    2018-01-01

    The main problems of providing a high-speed operation semiconductor lasers with a vertical microcavity (so-called "vertical-cavity surface-emitting lasers") under amplitude modulation and ways to solve them have been considered. The influence of the internal properties of the radiating active region and the electrical parasitic elements of the equivalent circuit of lasers are discussed. An overview of approaches that lead to an increase of the cutoff parasitic frequency, an increase of the differential gain of the active region, the possibility of the management of mode emission composition and the lifetime of photons in the optical microcavities, and reduction of the influence of thermal effects have been presented. The achieved level of modulation bandwidth of ˜30 GHz is close to the maximum achievable for the classical scheme of the direct-current modulation, which makes it necessary to use a multilevel modulation format to further increase the information capacity of optical channels constructed on the basis of vertical-cavity surface-emitting lasers.

  17. Improvement of the chromatic dispersion tolerance in coherent optical OFDM systems using shifted DFT windows for ultra-long-haul optical transmission systems.

    Science.gov (United States)

    Sung, Minkyu; Kim, Hoon; Lee, Jaehoon; Jeong, Jichai

    2014-09-22

    In a high-capacity ultra-long-haul optical coherent orthogonal frequency-division multiplexing (CO-OFDM) system, the dispersion tolerance is determined by the length of cyclic extension (CE). In this paper, we propose a novel scheme to substantially improve the dispersion tolerance of CO-OFDM systems without increasing the CE length. Multiple time-shifted discrete Fourier transform (DFT) windows are exploited at the receiver, each demodulating only a part of the subcarriers. Effectively, the proposed scheme reduces the bandwidth of the OFDM signals under demodulation. Numerical simulations are performed to show the improved dispersion tolerance of the proposed scheme in comparison with the conventional CO-OFDM system. We show that the dispersion tolerance improves by a factor equal to the number of DFT windows. The tradeoff between the improved dispersion tolerance and increased receiver complexity is also presented.

  18. Investigation of interference in multiple-input multiple-output wireless transmission at W band for an optical wireless integration system.

    Science.gov (United States)

    Li, Xinying; Yu, Jianjun; Dong, Ze; Zhang, Junwen; Chi, Nan; Yu, Jianguo

    2013-03-01

    We experimentally investigate the interference in multiple-input multiple-output (MIMO) wireless transmission by adjusting the relative locations of horn antennas (HAs) in a 100 GHz optical wireless integration system, which can deliver a 50 Gb/s polarization-division-multiplexing quadrature-phase-shift-keying signal over 80 km single-mode fiber-28 and a 2×2 MIMO wireless link. For the parallel 2×2 MIMO wireless link, each receiver HA can only get wireless power from the corresponding transmitter HA, while for the crossover ones, the receiver HA can get wireless power from two transmitter HAs. At the wireless receiver, polarization demultiplexing is realized by the constant modulus algorithm (CMA) in the digital-signal-processing part. Compared to the parallel case, wireless interference causes about 2 dB optical signal-to-noise ratio penalty at a bit-error ratio (BER) of 3.8×10(-3) for the crossover cases if similar CMA taps are employed. The increase in CMA tap length can reduce wireless interference and improve BER performance. Furthermore, more CMA taps should be adopted to overcome the severe wireless interference when two pairs of transmitter and receiver HAs have different wireless distances.

  19. Transmission system for distribution of video over long-haul optical point-to-point links using a microwave photonic filter in the frequency range of 0.01-10 GHz

    Science.gov (United States)

    Zaldívar Huerta, Ignacio E.; Pérez Montaña, Diego F.; Nava, Pablo Hernández; Juárez, Alejandro García; Asomoza, Jorge Rodríguez; Leal Cruz, Ana L.

    2013-12-01

    We experimentally demonstrate the use of an electro-optical transmission system for distribution of video over long-haul optical point-to-point links using a microwave photonic filter in the frequency range of 0.01-10 GHz. The frequency response of the microwave photonic filter consists of four band-pass windows centered at frequencies that can be tailored to the function of the spectral free range of the optical source, the chromatic dispersion parameter of the optical fiber used, as well as the length of the optical link. In particular, filtering effect is obtained by the interaction of an externally modulated multimode laser diode emitting at 1.5 μm associated to the length of a dispersive optical fiber. Filtered microwave signals are used as electrical carriers to transmit TV-signal over long-haul optical links point-to-point. Transmission of TV-signal coded on the microwave band-pass windows located at 4.62, 6.86, 4.0 and 6.0 GHz are achieved over optical links of 25.25 km and 28.25 km, respectively. Practical applications for this approach lie in the field of the FTTH access network for distribution of services as video, voice, and data.

  20. Heating tokamaks by parametric decay of intense extraordinary mode radiation

    International Nuclear Information System (INIS)

    Elder, G.B.; Perkins, F.W.

    1979-08-01

    Intense electron beam technology has developed coherent, very high power (350 megawatts) microwave sources at frequencies which are a modest fraction of the electron cyclotron frequency in tokamaks. Propagation into a plasma occurs via the extraordinary mode which is subject to parametric decay instabilities in the density range ω/sub o/ 2 2 < ω/sub o/(ω/sub o/ + Ω/sub e/). For an incident wave focused onto a hot spot by a dish antenna of radius rho, the effective threshold power P/sub o/ required to induced effective parametric heating is P/sub o/ approx. = 10 MW x/rho Ω/sub e//ω/sub o/ (T/sub e//1 keV)/sup 3/2/ where x denotes the distance to the hot spot

  1. MO-A-BRD-01: An Investigation of the Dynamic Response of a Novel Acousto-Optic Liquid Crystal Detector for Full-Field Transmission Ultrasound Breast Imaging

    International Nuclear Information System (INIS)

    Rosenfield, J.R.; La Riviere, P.J.; Sandhu, J.S.

    2014-01-01

    Purpose: To characterize the dynamic response of a novel acousto-optic (AO) liquid crystal detector for high-resolution transmission ultrasound breast imaging. Transient and steady-state lesion contrast were investigated to identify optimal transducer settings for our prototype imaging system consistent with the FDA limits of 1 W/cm 2 and 50 J/cm 2 on the incident acoustic intensity and the transmitted acoustic energy flux density. Methods: We have developed a full-field transmission ultrasound breast imaging system that uses monochromatic plane-wave illumination to acquire projection images of the compressed breast. The acoustic intensity transmitted through the breast is converted into a visual image by a proprietary liquid crystal detector operating on the basis of the AO effect. The dynamic response of the AO detector in the absence of an imaged breast was recorded by a CCD camera as a function of the acoustic field intensity and the detector exposure time. Additionally, a stereotactic needle biopsy breast phantom was used to investigate the change in opaque lesion contrast with increasing exposure time for a range of incident acoustic field intensities. Results: Using transducer voltages between 0.3 V and 0.8 V and exposure times of 3 minutes, a unique one-to-one mapping of incident acoustic intensity to steady-state optical brightness in the AO detector was observed. A transfer curve mapping acoustic intensity to steady-state optical brightness shows a high-contrast region analogous to the linear portion of the Hurter-Driffield curves of radiography. Using transducer voltages between 1 V and 1.75 V and exposure times of 90 s, the lesion contrast study demonstrated increasing lesion contrast with increasing breast exposure time and acoustic field intensity. Lesion-to-background contrast on the order of 0.80 was observed. Conclusion: Maximal lesion contrast in our prototype system can be obtained using the highest acoustic field intensity and the longest breast

  2. U.S./China Bilateral Symposium on Extraordinary Floods

    Science.gov (United States)

    Kirby, W.

    Accurate appraisal of the risk of extreme floods has long been of concern to hydrologists and water resources managers in both the United States and China. In order to exchange information, assess current developments, and discuss further needs in extreme flood analysis, the U.S. Geological Survey (USGS) and the Bureau of Hydrology of the Ministry of Water Resources and Electric Power of the People's Republic of China (PRC) held the Bilateral Symposium on the Analysis of Extraordinary Flood Events, October 14-18, 1985, in Nanjing, China. Co-convenors of the symposium were Marshall E. Moss (USGS) and Hua Shiqian (Nanjing Research Institute of Hydrology). Liang Ruiju (East China Technical University of Water Resources) was executive secretary of the organizing committee. Participants included 23 U.S. delegates, 36 Chinese delegates, and five guests from other countries. Of the U.S. delegates, 13 were from federal agencies, seven were from universities, and three were private consultants. The U.S. National Science Foundation gave financial support to the nonfederal U.S. delegates. Major topics covered in the 52 papers presented included detection of historical floods and evaluation of the uncertainties in their peak discharges and times of occurrence,frequency analysis and design flood determination in the presence of extraordinary floods and historic floods, anduse of storm data in determining design storms and design floods, The symposium was followed by a 6-day study tour in central China, during which laboratories, field activities, and offices of various water resources agencies were visited and sites of documented historic floods on the Yangtze River and its tributaries were examined.

  3. Optical Determination of Lead Chrome Green in Green Tea by Fourier Transform Infrared (FT-IR Transmission Spectroscopy.

    Directory of Open Access Journals (Sweden)

    Xiaoli Li

    Full Text Available The potential of Fourier transform infrared (FT-IR transmission spectroscopy for determination of lead chrome green in green tea was investigated based on chemometric methods. Firstly, the qualitative analysis of lead chrome green in tea was performed based on partial least squares discriminant analysis (PLS-DA, and the correct rate of classification was 100%. And then, a hybrid method of interval partial least squares (iPLS regression and successive projections algorithm (SPA was proposed to select characteristic wavenumbers for the quantitative analysis of lead chrome green in green tea, and 19 wavenumbers were obtained finally. Among these wavenumbers, 1384 (C = C, 1456, 1438, 1419(C = N, and 1506 (CNH cm-1 were the characteristic wavenumbers of lead chrome green. Then, these 19 wavenumbers were used to build determination models. The best model was achieved by least squares support vector machine (LS-SVMalgorithm with high coefficient of determination and low root-mean square error of prediction set (R2p = 0.864 and RMSEP = 0.291. All these results indicated the feasibility of IR spectra for detecting lead chrome green in green tea.

  4. A 1550-nm all-optical VCSEL-to-VCSEL wavelength conversion of a 8.5-Gb/s data signal and transmission over a 24.7-km fibre

    Science.gov (United States)

    Boiyo, D. Kiboi; Isoe, G. M.; Gamatham, R. R. G.; Leitch, A. W. R.; Gibbon, T. B.

    2016-02-01

    For the first time, we demonstrate, VCSEL-to-VCSEL wavelength conversion within the low attenuation 1550 nm window, including transmission over fibre and bit error rate (BER) performance characterization. We experimentally demonstrate a low injection power optical wavelength conversion by injecting an optical beam from a signal carrier master vertical cavity surface-emitting laser (VCSEL) into the side-mode of the slave VCSEL. This technique solves the challenge of wavelength collisions and also provides wavelength re-use in typical wavelength division multiplexed (WDM) systems. This paper, for the first time, uses two 1550 nm VCSELs with tunability range of 3 nm for a 5-9.8 mA bias current. The master VCSEL is modulated with a non-return-to-zero (NRZ) pseudo-random binary sequence (PRBS_27-1) 8.5 Gb/s data. A data conversion penalty of 1.1 dB is realized when a 15 dBm injection beam is used. The transmission performance of the converted wavelength from the slave VCSEL is evaluated using BER measurement at a 10-9 threshold. A 0.5 dB transmission penalty of the converted wavelength data is realized in an 8.5 Gb/s transmission over 24.7 km. This work is vital for optical fibre systems that may require wavelength switching for transmission of data signals.

  5. Generation of 1.024-Tb/s Nyquist-WDM phase-conjugated twin vector waves through polarization-insensitive optical parametric amplification enabling transmission over 4000-km dispersion-managed TWRS fiber

    DEFF Research Database (Denmark)

    Liu, Xiang; Hu, Hao; Chandrasekhar, S.

    2013-01-01

    We experimentally demonstrate the first Tb/s Nyquist-WDM phase-conjugated twin waves, consisting of eight 128-Gb/s PDM-QPSK signals and their idlers, by a broadband polarization-insensitive fiber optical parametric amplifier, enabling more than doubled reach in dispersion-managed transmission. © ...

  6. Design, manufacturing and alignment of a fluorescence imaging spectrometer based on refractive optics and a transmission grating

    Science.gov (United States)

    Lousberg, G. P.; Lemagne, F.; Gloesener, P.; Flebus, C.; Rougelot, S.; Coatantiec, C.; Harnisch, B.

    2017-11-01

    In the framework of the Fluorescence Explorer (FLEX) phase A/B1 study, an elegant breadboard (EBB) of an imaging spectrometer is designed, manufactured and aligned by AMOS, with Airbus Defence&Space as the prime Contractor of the study. The FLEX mission is one of the two candidates of the 8th Earth Explorer mission. The main constituting instrument of the FLEX mission is an imaging spectrometer observing vegetation fluorescence and reflectance with a high- and a low-resolution channels in the 500 nm -780 nm band. As part of the system feasibility study of the mission, a breadboard of the high-resolution channel of the instrument is designed and manufactured with a high representativeness of a future flight concept. The high-resolution channel is referred to as FIMAS (Fluorescence IMAging Spectrometer). The main purpose of the EBB is to demonstrate (1) the manufacturability of the instrument and (2) the compliance of the optical performances with respect to the science requirements (including spatial and spectral resolution and stray-light).

  7. 128 Gb/s TWDM PON system using dispersion-supported transmission method

    Science.gov (United States)

    Bindhaiq, Salem; Zulkifli, Nadiatulhuda; Supa'at, Abusahmah M.; Idrus, Sevia M.; Salleh, M. S.

    2017-11-01

    Time and wavelength division multiplexed passive optical network (TWDM-PON) trend is considered as the most extraordinary trend of the next generation solution to accommodate exponential traffic growth for converged new services. In this paper, we briefly review recent progress on TWDM-PON system through the use of low cost directly modulated lasers (DMLs) transmission for various line rate transmissions to date. Furthermore, through simulation, we propose and evaluate a cost effective way to upgrade TWDM-PON up to a symmetric capacity of 128 Gb/s using fiber Bragg gratings (FBGs) in optical line terminal (OLT) as a paramount dispersion manager in high speed light-wave systems in both upstream and downstream directions. A low cost and potential chirpless directed modulated grating laser (DMGL) is employed for downstream link and DML with a single delay-interferometer (DI) is employed for upstream link. After illustrating the demonstrated system architecture and configuration, we present the results and analysis to prove the system feasibility. The results show that a successful transmission is achieved over 40 km single mode fiber with a power budget of 33.7 dB, which could support 1:256 splitting ratio.

  8. Optical Communication over Plastic Optical Fibers Integrated Optical Receiver Technology

    CERN Document Server

    Atef, Mohamed

    2013-01-01

    This book presents high-performance data transmission over plastic optical fibers (POF) using integrated optical receivers having good properties with multilevel modulation, i.e. a higher sensitivity and higher data rate transmission over a longer plastic optical fiber length. Integrated optical receivers and transmitters with high linearity are introduced for multilevel communication. For binary high-data rate transmission over plastic optical fibers, an innovative receiver containing an equalizer is described leading also to a high performance of a plastic optical fiber link. The cheap standard PMMA SI-POF (step-index plastic optical fiber) has the lowest bandwidth and the highest attenuation among multimode fibers. This small bandwidth limits the maximum data rate which can be transmitted through plastic optical fibers. To overcome the problem of the plastic optical fibers high transmission loss, very sensitive receivers must be used to increase the transmitted length over POF. The plastic optical fiber li...

  9. Analysis of Experimentation Results on University Graduates' Readiness Formation to Act in Extraordinary Situations

    Science.gov (United States)

    Moloshavenko, Vera L.; Prozorova, Galina V.; Sienkiewicz, Lyudmila B.

    2016-01-01

    The article presents the experimentation on graduates' readiness formation to act in extraordinary situations conducted in the Tyumen Industrial University in training bachelors in "Oil and Gas Business". The criteria of graduates' readiness formation to act in extraordinary situations are the following: practicability, validity,…

  10. 78 FR 40665 - Cost Accounting Standards: CAS 413 Pension Adjustments for Extraordinary Events

    Science.gov (United States)

    2013-07-08

    ... Accounting Standards: CAS 413 Pension Adjustments for Extraordinary Events AGENCY: Cost Accounting Standards...: The Office of Federal Procurement Policy (OFPP), Cost Accounting Standards (CAS) Board, is conducting... Extraordinary Events. This is the first step in a four- step process that may result in a final rule. As part of...

  11. 40 CFR 80.73 - Inability to produce conforming gasoline in extraordinary circumstances.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Inability to produce conforming gasoline in extraordinary circumstances. 80.73 Section 80.73 Protection of Environment ENVIRONMENTAL... Gasoline § 80.73 Inability to produce conforming gasoline in extraordinary circumstances. In appropriate...

  12. A rigorous analysis of digital pre-emphasis and DAC resolution for interleaved DAC Nyquist-WDM signal generation in high-speed coherent optical transmission systems

    Science.gov (United States)

    Weng, Yi; Wang, Junyi; He, Xuan; Pan, Zhongqi

    2018-02-01

    The Nyquist spectral shaping techniques facilitate a promising solution to enhance spectral efficiency (SE) and further reduce the cost-per-bit in high-speed wavelength-division multiplexing (WDM) transmission systems. Hypothetically, any Nyquist WDM signals with arbitrary shapes can be generated by the use of the digital signal processing (DSP) based electrical filters (E-filter). Nonetheless, in actual 100G/ 200G coherent systems, the performance as well as DSP complexity are increasingly restricted by cost and power consumption. Henceforward it is indispensable to optimize DSP to accomplish the preferred performance at the least complexity. In this paper, we systematically investigated the minimum requirements and challenges of Nyquist WDM signal generation, particularly for higher-order modulation formats, including 16 quadrature amplitude modulation (QAM) or 64QAM. A variety of interrelated parameters, such as channel spacing and roll-off factor, have been evaluated to optimize the requirements of the digital-to-analog converter (DAC) resolution and transmitter E-filter bandwidth. The impact of spectral pre-emphasis has been predominantly enhanced via the proposed interleaved DAC architecture by at least 4%, and hence reducing the required optical signal to noise ratio (OSNR) at a bit error rate (BER) of 10-3 by over 0.45 dB at a channel spacing of 1.05 symbol rate and an optimized roll-off factor of 0.1. Furthermore, the requirements of sampling rate for different types of super-Gaussian E-filters are discussed for 64QAM Nyquist WDM transmission systems. Finally, the impact of the non-50% duty cycle error between sub-DACs upon the quality of the generated signals for the interleaved DAC structure has been analyzed.

  13. Effects of middle ear quasi-static stiffness on sound transmission quantified by a novel 3-axis optical force sensor.

    Science.gov (United States)

    Dobrev, Ivo; Sim, Jae Hoon; Aqtashi, Baktash; Huber, Alexander M; Linder, Thomas; Röösli, Christof

    2018-01-01

    Intra-operative quantification of the ossicle mobility could provide valuable feedback for the current status of the patient's conductive hearing. However, current methods for evaluation of middle ear mobility are mostly limited to the surgeon's subjective impression through manual palpation of the ossicles. This study investigates how middle ear transfer function is affected by stapes quasi-static stiffness of the ossicular chain. The stiffness of the middle ear is induced by a) using a novel fiber-optic 3-axis force sensor to quantify the quasi-static stiffness of the middle ear, and b) by artificial reduction of stapes mobility due to drying of the middle ear. Middle ear transfer function, defined as the ratio of the stapes footplate velocity versus the ear canal sound pressure, was measured with a single point LDV in two conditions. First, a controlled palpation force was applied at the stapes head in two in-plane (superior-inferior or posterior-anterior) directions, and at the incus lenticular process near the incudostapedial joint in the piston (lateral-medial) direction with a novel 3-axis PalpEar force sensor (Sensoptic, Losone, Switzerland), while the corresponding quasi-static displacement of the contact point was measured via a 3-axis micrometer stage. The palpation force was applied sequentially, step-wise in the range of 0.1-20 gF (1-200 mN). Second, measurements were repeated with various stages of stapes fixation, simulated by pre-load on the stapes head or drying of the temporal bone, and with severe ossicle immobilization, simulated by gluing of the stapes footplate. Simulated stapes fixation (forced drying of 5-15 min) severely decreases (20-30 dB) the low frequency (4 kHz) response. Stapes immobilization (gluing of the footplate) severely reduces (20-40 dB) the low and mid frequency response (force (Force-displacement measurements around the incudostapedial joint showed quasi-static stiffness in the range of 200-500 N/m for normal middle

  14. Sexual conflict explains the extraordinary diversity of mechanisms regulating mitochondrial inheritance.

    Science.gov (United States)

    Radzvilavicius, Arunas L; Lane, Nick; Pomiankowski, Andrew

    2017-10-26

    Mitochondria are predominantly inherited from the maternal gamete, even in unicellular organisms. Yet an extraordinary array of mechanisms enforce uniparental inheritance, which implies shifting selection pressures and multiple origins. We consider how this high turnover in mechanisms controlling uniparental inheritance arises using a novel evolutionary model in which control of mitochondrial transmission occurs either during spermatogenesis (by paternal nuclear genes) or at/after fertilization (by maternal nuclear genes). The model treats paternal leakage as an evolvable trait. Our evolutionary analysis shows that maternal control consistently favours strict uniparental inheritance with complete exclusion of sperm mitochondria, whereas some degree of paternal leakage of mitochondria is an expected outcome under paternal control. This difference arises because mito-nuclear linkage builds up with maternal control, allowing the greater variance created by asymmetric inheritance to boost the efficiency of purifying selection and bring benefits in the long term. In contrast, under paternal control, mito-nuclear linkage tends to be much weaker, giving greater advantage to the mixing of cytotypes, which improves mean fitness in the short term, even though it imposes a fitness cost to both mating types in the long term. Sexual conflict is an inevitable outcome when there is competition between maternal and paternal control of mitochondrial inheritance. If evolution has led to complete uniparental inheritance through maternal control, it creates selective pressure on the paternal nucleus in favour of subversion through paternal leakage, and vice versa. This selective divergence provides a reason for the repeated evolution of novel mechanisms that regulate the transmission of paternal mitochondria, both in the fertilized egg and spermatogenesis. Our analysis suggests that the widespread occurrence of paternal leakage and prevalence of heteroplasmy are natural outcomes of

  15. Extraordinary magnetoresistance in semiconductor/metal hybrids: A review

    KAUST Repository

    Sun, J.

    2013-02-13

    The Extraordinary Magnetoresistance (EMR) effect is a change in the resistance of a device upon the application of a magnetic field in hybrid structures, consisting of a semiconductor and a metal. The underlying principle of this phenomenon is a change of the current path in the hybrid structure upon application of a magnetic field, due to the Lorentz force. Specifically, the ratio of current, flowing through the highly conducting metal and the poorly conducting semiconductor, changes. The main factors for the device\\'s performance are: the device geometry, the conductivity of the metal and semiconductor, and the mobility of carriers in the semiconductor. Since the discovery of the EMR effect, much effort has been devoted to utilize its promising potential. In this review, a comprehensive overview of the research on the EMR effect and EMR devices is provided. Different geometries of EMR devices are compared with respect to MR ratio and output sensitivity, and the criteria of material selection for high-performance devices are discussed. 2013 by the authors.

  16. UFOs and nukes. Extraordinary encounters at nuclear weapons sites

    International Nuclear Information System (INIS)

    Hastings, Robert L.

    2015-01-01

    Everyone knows about the reported recovery of a crashed alien spaceship near Roswell, New Mexico in July 1947. However, most people are unaware that, at the time of the incident, Roswell Army Airfield was home to the world's only atomic bomber squadron, the 509th Bomb Group. Was this merely a coincidence? During the Cold War, the United States and the Soviet Union built thousands of the far more destructive hydrogen bombs, some of them a thousand times as destructive as the first atomic bombs dropped on Japan. If the nuclear standoff between the superpowers had erupted into World War III, human civilization - and perhaps the very survival of our species - would have been at risk. Did this ominous state of affairs come to the attention of outside observers? Was there a connection between the atomic bomber squadron based at Roswell and the reported crash of a UFO nearby? Did those who pilot the UFOs monitor the superpowers' nuclear arms race during the dangerous Cold War era? Do they scrutinize American and Russian weapons sites even now? UFOs and Nukes provides the startling and sometimes shocking answers to these questions. Veteran researcher Robert Hastings has investigated nuclear weapons-related UFO incidents for more than three decades and has interviewed more than 120 ex-US Air Force personnel, from former Airmen to retired Colonels, who witnessed extraordinary UFO encounters at nuclear weapons sites. Their amazing stories are presented here.

  17. Extraordinary experiences in its cultural and theoretical context.

    Science.gov (United States)

    von Lucadou, Walter; Wald, Franziska

    2014-06-01

    The growing complexity, opaqueness and specialization of many areas of life and - above all - a booming psychological and esoteric market create the necessity for counselling and advice for individuals who encounter so-called 'paranormal' experiences. These experiences are often interpreted as 'transpersonal' or 'spiritual', depending on the cultural background and religious traditions. The term 'spiritual crisis' has become a fashionable diagnosis with some transpersonal psychotherapists. Paranormal experiences, regardless of their acceptance of academic psychology and psychiatry, are still a taboo subject in society. The Parapsychological Counselling Office in Freiburg is a professional unit with governmental support, which helps individuals to cope with such experiences adequately. The work and responsibilities of the counselling centre are presented. A large collection of cases in the form of letters, which were sent in by individuals wanting to communicate their unusual or extraordinary experiences have been analysed. Some of the results are reported here. Finally, we discuss a special form of 'inexplicable experiences' based on a theoretical model. Its recommendations seem counter-intuitive but are ultimately successful. The model starts from a system-theoretical viewpoint and uses concepts such as complementarity and entanglement of generalized quantum theory (GQT) and the model of pragmatic information (MPI). Since it turned out that individuals who contact the counselling centre also offer their own interpretations and 'explanation', the question arises, how these resources can be used to help clients.

  18. Extraordinary Magnetoresistance in Semiconductor/Metal Hybrids: A Review

    Directory of Open Access Journals (Sweden)

    Jürgen Kosel

    2013-02-01

    Full Text Available The Extraordinary Magnetoresistance (EMR effect is a change in the resistance of a device upon the application of a magnetic field in hybrid structures, consisting of a semiconductor and a metal. The underlying principle of this phenomenon is a change of the current path in the hybrid structure upon application of a magnetic field, due to the Lorentz force. Specifically, the ratio of current, flowing through the highly conducting metal and the poorly conducting semiconductor, changes. The main factors for the device’s performance are: the device geometry, the conductivity of the metal and semiconductor, and the mobility of carriers in the semiconductor. Since the discovery of the EMR effect, much effort has been devoted to utilize its promising potential. In this review, a comprehensive overview of the research on the EMR effect and EMR devices is provided. Different geometries of EMR devices are compared with respect to MR ratio and output sensitivity, and the criteria of material selection for high-performance devices are discussed.

  19. Extraordinary Magnetoresistance in Semiconductor/Metal Hybrids: A Review

    Science.gov (United States)

    Sun, Jian; Kosel, Jürgen

    2013-01-01

    The Extraordinary Magnetoresistance (EMR) effect is a change in the resistance of a device upon the application of a magnetic field in hybrid structures, consisting of a semiconductor and a metal. The underlying principle of this phenomenon is a change of the current path in the hybrid structure upon application of a magnetic field, due to the Lorentz force. Specifically, the ratio of current, flowing through the highly conducting metal and the poorly conducting semiconductor, changes. The main factors for the device’s performance are: the device geometry, the conductivity of the metal and semiconductor, and the mobility of carriers in the semiconductor. Since the discovery of the EMR effect, much effort has been devoted to utilize its promising potential. In this review, a comprehensive overview of the research on the EMR effect and EMR devices is provided. Different geometries of EMR devices are compared with respect to MR ratio and output sensitivity, and the criteria of material selection for high-performance devices are discussed. PMID:28809321

  20. Performance Study of optical Modulator based on electrooptic effect

    International Nuclear Information System (INIS)

    Palodiya, V; Raghuwanshi, S K

    2016-01-01

    In this paper, we have studied and derive performance parameter of highly integrated Lithium Niobate optical modulator. This is a chirp free modulator having low switching voltage and large bandwidth. For an external modulator in which travelling-wave electrodes length L imposed the modulating switching voltage, the product of V_π and L is fixed for a given electro optic material Lithium Niobate. We investigate to achieve a low V_π by both magnitude of the electro-optic coefficient for a wide variety of electro-optic materials. A Sellmeier equation for the extraordinary index of congruent lithium niobate is derived. For phase-matching, predictions are accmate for temperature between room temperature 250°C and wavelength ranging from 0.4 to 5µm. The Sellmeier equations predict more accmately refractive indices at long wavelengths. Theoretical result is confirmed by simulated results. We have analysed the various parameters such as switching voltage, device performance index, time constant, transmittance, cut-off frequency, 3-dB bandwidth, power absorption coefficient and transmission bit rate of Lithium Niobate optical Modulator based on electro -optic effect. (paper)

  1. In-situ investigation of the order-disorder transition in Cu2ZnSnSe4 by optical transmission spectroscopy

    Directory of Open Access Journals (Sweden)

    Christiane Stroth

    2017-02-01

    Full Text Available The existence of disorder is one possible reason for the limited performance of kesterite solar cells. Therefore further knowledge of the order-disorder phase transition, of factors which influence the degree of order and of methods to determine this material property is still required. In this study we investigated the order-disorder transition in the kesterite material Cu2ZnSnSe4 by in-situ optical transmission spectroscopy during heat treatments. We show in-situ results for the temperature dependence of the band gap and its tailing properties. The influence of cooling rates on the phase transition was analyzed as well as the ordering kinetics during annealing at a constant temperature. The critical temperature of the phase transition was determined and the existence of a control temperature range is shown, which allows for controlling the degree of order by the cooling rate within this range. Additionally we performed Raman analysis to link Raman spectra to the degree of order in Cu2ZnSnSe4. A correlation between the intensity ratio of A-modes as well as B-/ E- Raman modes and the degree of order was found.

  2. Fabrication of nanostructured transmissive optical devices on ITO-glass with UV1116 photoresist using high-energy electron beam lithography

    Science.gov (United States)

    Williams, Calum; Bartholomew, Richard; Rughoobur, Girish; Gordon, George S. D.; Flewitt, Andrew J.; Wilkinson, Timothy D.

    2016-12-01

    High-energy electron beam lithography for patterning nanostructures on insulating substrates can be challenging. For high resolution, conventional resists require large exposure doses and for reasonable throughput, using typical beam currents leads to charge dissipation problems. Here, we use UV1116 photoresist (Dow Chemical Company), designed for photolithographic technologies, with a relatively low area dose at a standard operating current (80 kV, 40-50 μC cm-2, 1 nAs-1) to pattern over large areas on commercially coated ITO-glass cover slips. The minimum linewidth fabricated was ˜33 nm with 80 nm spacing; for isolated structures, ˜45 nm structural width with 50 nm separation. Due to the low beam dose, and nA current, throughput is high. This work highlights the use of UV1116 photoresist as an alternative to conventional e-beam resists on insulating substrates. To evaluate suitability, we fabricate a range of transmissive optical devices, that could find application for customized wire-grid polarisers and spectral filters for imaging, which operate based on the excitation of surface plasmon polaritons in nanosized geometries, with arrays encompassing areas ˜0.25 cm2.

  3. The discrepancies between theory and experiment in the optical emission of monolayer In(Ga)N quantum wells revisited by transmission electron microscopy

    Science.gov (United States)

    Suski, T.; Schulz, T.; Albrecht, M.; Wang, X. Q.; Gorczyca, I.; Skrobas, K.; Christensen, N. E.; Svane, A.

    2014-05-01

    Quantitative high resolution transmission electron microscopy studies of intentionally grown 1InN/nGaN short-period superlattices (SLs) were performed. The structures were found to consist of an InxGa1-xN monolayer with an Indium content of x = 0.33 instead of the intended x = 1. Self-consistent calculations of the band structures of 1In0.33Ga0.67N/nGaN SLs were carried out, including a semi-empirical correction for the band gaps. The calculated band gap, Eg, as well as its pressure derivative, dEg/dp, are in very good agreement with the measured photoluminescence energy, EPL, and its pressure derivative, dEPL/dp, for a series of 1In0.33Ga0.67N/nGaN samples with n ranging from 2 to 40. This resolves a discrepancy found earlier between measured and calculated optical emission properties, as those calculations were made with the assumption of a 1InN/nGaN SL composition.

  4. Optical fibre-lightning arrester cable appliances. Its repercussion in concrete unconventional power transmission lines projects; Aplicacao de cabo para-raios composto com fibra optica. Sua repercursao em projetos de LT`s concreto nao convencionais

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, Ramon Sade [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil)

    1993-12-31

    With the adoption of lightning rod cables made of Optical Fibre, (in systems over Europe, Japan and North America), these became very popular in Countries capable of installing the system. The Brazilian electrical party was then challenged by a new technological experience: the lightning rod cable for lines of transmission has specific characteristics. The particularity of the electrical system in Brazil in relation to the diversity of the parameters involved, and the necessity to clarifying the concepts, take us to new strategies in planning and measuring our Power Transmission Lines 4 refs., 1 tab.

  5. Extraordinary proliferation of microorganisms in aposymbiotic pea aphids, Acyrthosiphon pisum.

    Science.gov (United States)

    Nakabachi, Atsushi; Ishikawa, Hajime; Kudo, Toshiaki

    2003-03-01

    Aposymbiotic pea aphids, which were deprived of their intracellular symbiotic bacterium, Buchnera, exhibit growth retardation and no fecundity. High performance liquid chromatographic (HPLC) analysis revealed that these aposymbiotic aphids, when reared on broad bean plants, accumulated a large amount of histamine. To assess the possibility of extraordinary proliferation of microorganisms other than Buchnera, we enumerated eubacteria and fungi in aphids using the real-time quantitative PCR method that targets genes encoding small-subunit rRNAs. The result showed that these microorganisms were extremely abundant in the aposymbiotic aphids reared on plants. Microbial communities in aposymbiotic aphids were further profiled by phylogenetic analysis of small-subunit rDNAs. Of 172 nonchimeric sequences of fungal 18S rDNAs, 138 (80.2%) belonged to the phylum Ascomycota. Among them, 21 clustered within a monophyletic group consisting of insect-pathogenic fungi and yeast-like symbionts of homopteran insects. Thirty-one (18.0%), two (1.2%), and one (0.6%) clones were clustered within the Basidiomycota, Zygomycota, and Oomycota, respectively. Of 167 nonchimeric sequences of eubacterial 16S rDNAs, 84 (50.3%) belonged to the gamma-subdivision of Proteobacteria to which most primary endosymbionts of insects and prolific histamine producers belong. Forty (24.0%), 25 (15.0%), 10 (6.0%), and five (3.0%) clones were clustered within alpha-Proteobacteria, Cytophaga-Flavobacterium-Bacteroides (CFB) group, Actinobacteria, and beta-Proteobacteria, respectively. Three had no phylogenetic association with known taxonomic divisions. None of the sequences studied in this study coincided exactly with those deposited in GenBank.

  6. DMPD: Gram-negative endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 1916089 Gram-negative endotoxin: an extraordinary lipid with profound effects oneuk...ep;5(12):2652-60. (.png) (.svg) (.html) (.csml) Show Gram-negative endotoxin: an extraordinary lipid with profound effects...tive endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. Authors Raetz

  7. Simultaneous determination of ordinary and extraordinary refractive index dispersions of nematic liquid crystals in the visible and near-infrared regions from an interference spectrum

    Science.gov (United States)

    Ozaki, Ryotaro; Nishi, Koji; Kan, Takayuki; Kadowaki, Kazunori

    2016-10-01

    An improved interference method is proposed to determine ordinary and extraordinary refractive index dispersions of nematic liquid crystals (LCs). In this method, an LC cell coated with a thin metal layer is used as a Fabry-Perot interferometer, which shows us a sharp transmission fringe. To ensure high reliability, the wavelength dispersion of the refractive index of the metal is taken into account in fitting calculation. In spite of measuring ordinary and extraordinary components, the LC cell, polarizers, and other equipment are not rotated during the experiment. The index evaluation from a single spectrum avoids errors depending on the measurement position owing to non-uniformities of molecular orientation and cell thickness because we can obtain the two indices at exactly the same position. This system can adapt to a wide frequency range and does not require any specific wavelength light source or laser. We demonstrate the determination of ordinary and extraordinary refractive index dispersions of a nematic liquid crystal in the visible and near-infrared regions. Furthermore, we quantitatively reproduce the measured spectrum by calculation using the measured refractive indices.

  8. Factorial-based response-surface modeling with confidence intervals for optimizing thermal-optical transmission analysis of atmospheric black carbon

    International Nuclear Information System (INIS)

    Conny, J.M.; Norris, G.A.; Gould, T.R.

    2009-01-01

    Thermal-optical transmission (TOT) analysis measures black carbon (BC) in atmospheric aerosol on a fibrous filter. The method pyrolyzes organic carbon (OC) and employs laser light absorption to distinguish BC from the pyrolyzed OC; however, the instrument does not necessarily separate the two physically. In addition, a comprehensive temperature protocol for the analysis based on the Beer-Lambert Law remains elusive. Here, empirical response-surface modeling was used to show how the temperature protocol in TOT analysis can be modified to distinguish pyrolyzed OC from BC based on the Beer-Lambert Law. We determined the apparent specific absorption cross sections for pyrolyzed OC (σ Char ) and BC (σ BC ), which accounted for individual absorption enhancement effects within the filter. Response-surface models of these cross sections were derived from a three-factor central-composite factorial experimental design: temperature and duration of the high-temperature step in the helium phase, and the heating increase in the helium-oxygen phase. The response surface for σ BC , which varied with instrument conditions, revealed a ridge indicating the correct conditions for OC pyrolysis in helium. The intersection of the σ BC and σ Char surfaces indicated the conditions where the cross sections were equivalent, satisfying an important assumption upon which the method relies. 95% confidence interval surfaces defined a confidence region for a range of pyrolysis conditions. Analyses of wintertime samples from Seattle, WA revealed a temperature between 830 deg. C and 850 deg. C as most suitable for the helium high-temperature step lasting 150 s. However, a temperature as low as 750 deg. C could not be rejected statistically

  9. A top-contacted extraordinary magnetoresistance sensor fabricated with an unpatterned semiconductor epilayer

    KAUST Repository

    Sun, Jian; Kosel, Jü rgen

    2013-01-01

    An extraordinary magnetoresistance device is developed from an unpatterned semiconductor epilayer onto which the metal contacts are fabricated. Compared with conventionally fabricated devices, for which semiconductor patterning and precise alignment

  10. Optimization of an extraordinary magnetoresistance sensor in the semiconductor-metal hybrid structure

    KAUST Repository

    Sun, Jian; Kosel, Jü rgen; Gooneratne, Chinthaka Pasan; Soh, Yeongah

    2010-01-01

    The purpose of this paper is to show by numerical computation how geometric parameters influence the Extraordinary Magnetoresistance (EMR) effect in an InAs-Au hybrid device. Symmetric IVVI and VIIV configurations were considered. The results show

  11. Extraordinary Magnetoresistance Effect in Semiconductor/Metal Hybrid Structure

    KAUST Repository

    Sun, Jian

    2013-06-27

    In this dissertation, the extraordinary magnetoresistance (EMR) effect in semiconductor/metal hybrid structures is studied to improve the performance in sensing applications. Using two-dimensional finite element simulations, the geometric dependence of the output sensitivity, which is a more relevant parameter for EMR sensors than the magnetoresistance (MR), is studied. The results show that the optimal geometry in this case is different from the geometry reported before, where the MR ratio was optimized. A device consisting of a semiconductor bar with length/width ratio of 5~10 and having only 2 contacts is found to exhibit the highest sensitivity. A newly developed three-dimensional finite element model is employed to investigate parameters that have been neglected with the two dimensional simulations utilized so far, i.e., thickness of metal shunt and arbitrary semiconductor/metal interface. The simulations show the influence of those parameters on the sensitivity is up to 10 %. The model also enables exploring the EMR effect in planar magnetic fields. In case of a bar device, the sensitivity to planar fields is about 15 % to 20 % of the one to perpendicular fields. 5 A “top-contacted” structure is proposed to reduce the complexity of fabrication, where neither patterning of the semiconductor nor precise alignment is required. A comparison of the new structure with a conventionally fabricated device shows that a similar magnetic field resolution of 24 nT/√Hz is obtained. A new 3-contact device is developed improving the poor low-field sensitivity observed in conventional EMR devices, resulting from its parabolic magnetoresistance response. The 3-contact device provides a considerable boost of the low field response by combining the Hall effect with the EMR effect, resulting in an increase of the output sensitivity by 5 times at 0.01 T compared to a 2-contact device. The results of this dissertation provide new insights into the optimization of EMR devices

  12. The Concept of Extraordinary Crime in Indonesia Legal System: is The Concept An Effective Criminal Policy?

    Directory of Open Access Journals (Sweden)

    Vidya Prahassacitta

    2016-10-01

    Full Text Available The concept of extraordinary crime was a common concept in Indonesia. Adopts from the concept of the most serious crime in Rome Statute and adjusted with the Indonesian legal system. Then it developed wider and introduced into terrorism, corruption, drug abuse offenses, and child sexual abuse in legislations and Constitutional Court verdicts. The implementation of this concept generated some consequences in drafting and formulating the legislation as part of penal policy. This leads to two legal problems; first, what was the categorization of the concept of extraordinary crime? and second, what were the consequences of the concept extraordinary crime in accordance with penal policy?. Normative law research with literature study method, This was a conducted as the response of both legal problems. Using secondary data from legislation, Constitutional Court verdicts, book and journal, this research concludes that; the concept of extraordinary crime parts of criminal policy does not have any standard for the categorization. Then, as consequences of the implementation of the concept of extraordinary crime in several penal efforts are formulating in legislations. The penalty effort is not limited to criminalization and sentencing aspects but wider and shall be in line with the strategy of crime eradication and welfare protection purposes. To reach the effectiveness of the criminal policy of the concept of extraordinary crime, the penalty effort shall be in line with criminal law principles and human right basic principles.

  13. Transmission of Information: An Overview.

    Science.gov (United States)

    Thoma, George R.

    1981-01-01

    Outlines the basic principles underlying the transmission of information, including analog and digital modulation, limitations to communications, configurations of communications networks, optical fiber cables, and earth satellites. Six references are cited. (FM)

  14. Neuroglial Transmission

    DEFF Research Database (Denmark)

    Gundersen, Vidar; Storm-Mathisen, Jon; Bergersen, Linda Hildegard

    2015-01-01

    as a signaling substance recently shown to act on specific lactate receptors in the brain. Complementing neurotransmission at a synapse, neuroglial transmission often implies diffusion of the transmitter over a longer distance and concurs with the concept of volume transmission. Transmission from glia modulates...... synaptic neurotransmission based on energetic and other local conditions in a volume of tissue surrounding the individual synapse. Neuroglial transmission appears to contribute significantly to brain functions such as memory, as well as to prevalent neuropathologies....

  15. Radio observations reveal a smooth circumstellar environment around the extraordinary type Ib supernova 2012au

    Energy Technology Data Exchange (ETDEWEB)

    Kamble, Atish; Soderberg, Alicia M.; Margutti, Raffaella; Milisavljevic, Dan; Chakraborti, Sayan; Dittmann, Jason; Drout, Maria; Sanders, Nathan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Chomiuk, Laura [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Medvedev, Mikhail [The Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045 (United States); Chevalier, Roger [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Chugai, Nikolai [Institute of Astronomy, Russian Academy of Sciences, Pyatnitskaya 48, 109017 Moscow (Russian Federation); Fransson, Claes [Department of Astronomy, The Oskar Klein Centre, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden); Nakar, Ehud, E-mail: atish.vyas@gmail.com [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)

    2014-12-10

    We present extensive radio and X-ray observations of SN 2012au, an energetic, radio-luminous supernova of Type Ib that exhibits multi-wavelength properties bridging subsets of hydrogen-poor superluminous supernovae, hypernovae, and normal core-collapse supernovae. The observations closely follow models of synchrotron emission from a shock-heated circumburst medium that has a wind density profile (ρ∝r {sup –2}). We infer a sub-relativistic velocity for the shock wave v ≈ 0.2 c and a radius of r ≈ 1.4 × 10{sup 16}cm at 25 days after the estimated date of explosion. For a wind velocity of 1000 km s{sup –1}, we determine the mass-loss rate of the progenitor to be M-dot =3.6×10{sup −6} M{sub ⊙} yr{sup −1}, consistent with the estimates from X-ray observations. We estimate the total internal energy of the radio-emitting material to be E ≈ 10{sup 47} erg, which is intermediate to SN 1998bw and SN 2002ap. The evolution of the radio light curve of SN 2012au is in agreement with its interaction with a smoothly distributed circumburst medium and the absence of stellar shells ejected from previous outbursts out to r ≈ 10{sup 17} cm from the supernova site. We conclude that the bright radio emission from SN 2012au was not dissimilar from other core-collapse supernovae despite its extraordinary optical properties, and that the evolution of the SN 2012au progenitor star was relatively quiet, marked with a steady mass loss, during the final years preceding explosion.

  16. An extraordinary directive radiation based on optical antimatter at near infrared.

    Science.gov (United States)

    Mocella, Vito; Dardano, Principia; Rendina, Ivo; Cabrini, Stefano

    2010-11-22

    In this paper we discuss and experimentally demonstrate that in a quasi- zero-average-refractive-index (QZAI) metamaterial, in correspondence of a divergent source in near infrared (λ = 1.55 μm) the light scattered out is extremely directive (Δθ(out) = 0.06°), coupling with diffraction order of the alternating complementary media grating. With a high degree of accuracy the measurements prove also the excellent vertical confinement of the beam even in the air region of the metamaterial, in absence of any simple vertical confinement mechanism. This extremely sensitive device works on a large contact area and open news perspective to integrated spectroscopy.

  17. Data Transmission and Thermo-Optic Tuning Performance of Dielectric-Loaded Plasmonic Structures Hetero-Integrated on a Silicon Chip

    DEFF Research Database (Denmark)

    Giannoulis, G.; Kalavrouziotis, D.; Apostolopoulos, D.

    2012-01-01

    We demonstrate experimental evidence of the data capture and the low-energy thermo-optic tuning credentials of dielectric-loaded plasmonic structures integrated on a silicon chip. We show 7-nm thermo-optical tuning of a plasmonic racetrack-resonator with less than 3.3 mW required electrical power...

  18. Transmission issues

    International Nuclear Information System (INIS)

    Bradford, J.; Wilson, L.; Thon, S.; Millar, N.

    2005-01-01

    This session on transmission issues focused on the role that transmission plays in electricity markets and the importance of getting the market structure right in terms of generation divestiture with buy back contracts, demand side responsive programs, transmission upgrades and long term contracts. The difficulties of distinguishing between market power and scarcity were examined along with some of the complications that ensue if transmission experiences congestion, as exemplified by the August 2003 blackout in eastern North America. The presentations described the best ways to handle transmission issues, and debated whether transmission should be deregulated or follow market forces. Issues of interconnections and reliability of connections were also debated along with the attempt to integrate renewables into the grid. Some presentations identified what new transmission must be built and what must be done to ensure that transmission gets built. The challenges and business opportunities for transmission in Alberta were discussed with reference to plans to invest in new infrastructure, where it is going outside of the province and how it works with other jurisdictions. Manitoba's Conawapa Hydro Project and its 2000 MW tie line to Ontario was also discussed. Some examples of non-optimal use of interconnections in Europe were also discussed in an effort to learn from these mistakes and avoid them in Canada. tabs., figs

  19. The Legal Framework Of Human Rights Crime As An Extraordinary Crime

    Directory of Open Access Journals (Sweden)

    Dedy Siswadi

    2015-08-01

    Full Text Available Abstract This research reviews the legal framework of human rights crime as an extraordinary crime as an approach in the settlement of criminal cases. The outcomes of the research indicate that modern human rights law developed out of customs and theories that established the rights of the individual in relation to the state. Disagreements regarding human rights violations which can only be done by the state and its agents or can also be done by non-government units still exist at the moment. As it turns out in practice however it has certain weaknesses particularly in legislation concerning serious crimes of human rights both as ius constituendum and ius constitutum still needs to be improved especially in the implementation of human rights on judiciary system. Therefore serious crimes against human rights are included as an extraordinary crime. The handling of the cases was incredible and special has become a logical consequence to be included as an extraordinary crime.

  20. Nonreciprocal light transmission based on the thermal radiative effect

    DEFF Research Database (Denmark)

    Liu, Li; Dong, Jianji; Ding, Yunhong

    2015-01-01

    Nonreciprocal light transmission is critical in building optical isolations and circulations in optical communication systems. Achieving high optical isolation and broad bandwidth with CMOS-compatibility are still difficult in silicon nano-photonics. Here we first experimentally demonstrate that ...

  1. 320 Gb/s Single polarization OTDM Transmission over 80 km Standard Transmission Fiber

    DEFF Research Database (Denmark)

    Siahlo, Andrei; Seoane, Jorge; Clausen, Anders

    2005-01-01

    Optical time-division multiplexing (OTDM) is an attractive technique for increasing the capacity of optical transmission systems. 320 Gbit/s single-channel and single-polarization error-free transmission over continuous spans of either 80 km SMF or 77 km NZDSF are realized.......Optical time-division multiplexing (OTDM) is an attractive technique for increasing the capacity of optical transmission systems. 320 Gbit/s single-channel and single-polarization error-free transmission over continuous spans of either 80 km SMF or 77 km NZDSF are realized....

  2. Advanced digital optical communications

    CERN Document Server

    Binh, Le Nguyen

    2015-01-01

    This book provides a fundamental understanding of digital communication applications in optical communication technologies. Emphasizing operation principles versus mathematical analysis, the Second Edition includes new coverage of superchannel optical transmission systems, metropolitan and long-haul optical systems and networks, and Nyquist pulse shaping and high spectral efficiency of optical transmission systems, as well as new homework problems and examples. Featuring theoretical foundations as well as practical case studies, the text focuses on enhancements to digital technologies that are

  3. Extraordinary Appeal´S General Repercussion and Third Parties in the Constitutional Jurisdiction

    Directory of Open Access Journals (Sweden)

    Edilene Lôbo

    2016-06-01

    Full Text Available General repercussion, aiming to fight excess of extraordinary appeals and unifying jurisprudence through serial rulings, reveals an essential technique to make collective rights feasible. However, recent procedural legislation gave powers to decide on the matter (exercising the admissibility appraisal of the extraordinary appeal to the lower courts, taking it from the Brazilian Supreme Court, at the same time only accepting organizations as thirdparties. This situation goes against the Democratic Constitutional Procedure paradigm, signaling this work´s goal: to redesign the situation starting from the Open Society of Interpreters theory and from the legal procedure as a theory of the democratic ruling.

  4. Sixteen-state magnetic memory based on the extraordinary Hall effect

    International Nuclear Information System (INIS)

    Segal, A.; Karpovski, M.; Gerber, A.

    2012-01-01

    We report on a proof-of-concept study of split-cell magnetic storage in which multi-bit magnetic memory cells are composed of several multilevel ferromagnetic dots with perpendicular magnetic anisotropy. Extraordinary Hall effect is used for reading the data. Feasibility of the approach is supported by realization of four-, eight- and sixteen- state cells. - Highlights: ► We propose a novel structure of multi-bit magnetic random access memory. ► Each cell contains several interconnected storage dots. ► Extraordinary Hall effect is used for reading the data. ► Four-, eight- and sixteen-state cells have been realized.

  5. Transmission eigenvalues

    Science.gov (United States)

    Cakoni, Fioralba; Haddar, Houssem

    2013-10-01

    In inverse scattering theory, transmission eigenvalues can be seen as the extension of the notion of resonant frequencies for impenetrable objects to the case of penetrable dielectrics. The transmission eigenvalue problem is a relatively late arrival to the spectral theory of partial differential equations. Its first appearance was in 1986 in a paper by Kirsch who was investigating the denseness of far-field patterns for scattering solutions of the Helmholtz equation or, in more modern terminology, the injectivity of the far-field operator [1]. The paper of Kirsch was soon followed by a more systematic study by Colton and Monk in the context of developing the dual space method for solving the inverse scattering problem for acoustic waves in an inhomogeneous medium [2]. In this paper they showed that for a spherically stratified media transmission eigenvalues existed and formed a discrete set. Numerical examples were also given showing that in principle transmission eigenvalues could be determined from the far-field data. This first period of interest in transmission eigenvalues was concluded with papers by Colton et al in 1989 [3] and Rynne and Sleeman in 1991 [4] showing that for an inhomogeneous medium (not necessarily spherically stratified) transmission eigenvalues, if they existed, formed a discrete set. For the next seventeen years transmission eigenvalues were ignored. This was mainly due to the fact that, with the introduction of various sampling methods to determine the shape of an inhomogeneous medium from far-field data, transmission eigenvalues were something to be avoided and hence the fact that transmission eigenvalues formed at most a discrete set was deemed to be sufficient. In addition, questions related to the existence of transmission eigenvalues or the structure of associated eigenvectors were recognized as being particularly difficult due to the nonlinearity of the eigenvalue problem and the special structure of the associated transmission

  6. Extraordinary sex ratios: cultural effects on ecological consequences.

    Directory of Open Access Journals (Sweden)

    Ferenc Molnár

    Full Text Available We model sex-structured population dynamics to analyze pairwise competition between groups differing both genetically and culturally. A sex-ratio allele is expressed in the heterogametic sex only, so that assumptions of Fisher's analysis do not apply. Sex-ratio evolution drives cultural evolution of a group-associated trait governing mortality in the homogametic sex. The two-sex dynamics under resource limitation induces a strong Allee effect that depends on both sex ratio and cultural trait values. We describe the resulting threshold, separating extinction from positive growth, as a function of female and male densities. When initial conditions avoid extinction due to the Allee effect, different sex ratios cannot coexist; in our model, greater female allocation always invades and excludes a lesser allocation. But the culturally transmitted trait interacts with the sex ratio to determine the ecological consequences of successful invasion. The invading female allocation may permit population persistence at self-regulated equilibrium. For this case, the resident culture may be excluded, or may coexist with the invader culture. That is, a single sex-ratio allele in females and a cultural dimorphism in male mortality can persist; a low-mortality resident trait is maintained by father-to-son cultural transmission. Otherwise, the successfully invading female allocation excludes the resident allele and culture and then drives the population to extinction via a shortage of males. Finally, we show that the results obtained under homogeneous mixing hold, with caveats, in a spatially explicit model with local mating and diffusive dispersal in both sexes.

  7. Optical response of large-area aluminum-coated nano-bucket arrays on flexible PET substrates

    Science.gov (United States)

    Hohertz, Donna; Chuo, Yindar; Omrane, Badr; Landrock, Clint; Kavanagh, Karen L.

    2014-09-01

    The high-cost of fabrication of nanohole arrays for extraordinary optical transmission, surface-plasmon-resonance-based sensors, inhibits their widespread commercial adoption. Production typically involves the application of small-area patterning techniques, such as focused-ion-beam milling, and electron-beam lithography onto high-cost gold-coated substrates. Moving to lower-cost manufacturing is a critical step for applications such as the detection of environmental oil-leaks, or water quality assurance. In these applications, the sensitivity requirements are relatively low, and a bio-compatible inert surface, such as gold, is unnecessary. We report on the optical response of aluminum-coated nano-bucket arrays fabricated on flexible polyethylene terephthalate substrates. The arrays are fabricated using an economical roll-to-roll UV-casting process from large sheets of nickel templates generated from master quartz stamps. The nano-featured surface is subsequently coated with 50 nm of thermally-evaporated aluminum. The roll-to-roll production process has a 97% yield over a 600 m roll producing nano-buckets with 240 nm diameters, 300 nm deep, with a 70° taper. When exposed to a series of refractive index standards (glucose solutions), changes in the locations of the resonance transmission peaks result in optical sensitivities as high as 390 ± 20 nm/RIU. The peak transmission is approximately 5% of illumination, well within the sensitivity requirements of most common low-cost detectors.

  8. Quantifying Transmission.

    Science.gov (United States)

    Woolhouse, Mark

    2017-07-01

    Transmissibility is the defining characteristic of infectious diseases. Quantifying transmission matters for understanding infectious disease epidemiology and designing evidence-based disease control programs. Tracing individual transmission events can be achieved by epidemiological investigation coupled with pathogen typing or genome sequencing. Individual infectiousness can be estimated by measuring pathogen loads, but few studies have directly estimated the ability of infected hosts to transmit to uninfected hosts. Individuals' opportunities to transmit infection are dependent on behavioral and other risk factors relevant given the transmission route of the pathogen concerned. Transmission at the population level can be quantified through knowledge of risk factors in the population or phylogeographic analysis of pathogen sequence data. Mathematical model-based approaches require estimation of the per capita transmission rate and basic reproduction number, obtained by fitting models to case data and/or analysis of pathogen sequence data. Heterogeneities in infectiousness, contact behavior, and susceptibility can have substantial effects on the epidemiology of an infectious disease, so estimates of only mean values may be insufficient. For some pathogens, super-shedders (infected individuals who are highly infectious) and super-spreaders (individuals with more opportunities to transmit infection) may be important. Future work on quantifying transmission should involve integrated analyses of multiple data sources.

  9. Experimental demonstration of all-optical 781.25-Mb/s binary phase-coded UWB Signal Generation and Transmission

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2009-01-01

    the requirements of Federal Communications Commission regulations. We experimentally demonstrated a 781.25-Mb/s UWB-over-fiber transmission system. A digital-signal-processing-based receiver is employed to calculate the bit-error rate. Our proposed system has potential application in future high-speed UWB impulse...

  10. Extraordinary Hall effect in Co implanted GaAs hybrid magnetic semiconductors

    International Nuclear Information System (INIS)

    Honda, S.; Tateishi, K.; Nawate, M.; Sakamoto, I.

    2004-01-01

    Hybrid Co/GaAs ferromagnetic semiconductors have been prepared by implantation method. In these samples, sheet resistance shows weak temperature dependence, and the extraordinary Hall effect with positive coefficient is observed. In small Co content samples, Hall resistance increases with decreasing temperature and maximum value of 3.6x10 -2 Ω is obtained at 150 K

  11. The right to appeal a judgment of the Extraordinary Chambers in the courts of Cambodia

    NARCIS (Netherlands)

    O'Neill, L.; Sluiter, G.

    2009-01-01

    In early 2007, we submitted a report to the Extraordinary Chambers in the Courts of Cambodia commenting on several aspects of its then-draft Internal Rules, including whether the ECCC’s envisaged appeal system adhered to international standards. The Internal Rules were adopted in June 2007, and then

  12. The psychologist, the psychoanalyst and the 'extraordinary child' in postwar British science fiction.

    Science.gov (United States)

    Tisdall, Laura

    2016-12-01

    A sudden influx of portrayals of 'extraordinary children' emerged in British science fiction after the Second World War. Such children both violated and confirmed the new set of expectations about ordinary childhood that emerged from the findings of developmental psychologists around the same time. Previous work on extraordinary children in both science fiction and horror has tended to confine the phenomenon to an 'evil child boom' within the American filmmaking industry in the 1970s. This article suggests that a much earlier trend is visible in British postwar science fiction texts, analysing a cluster of novels that emerged in the 1950s: Arthur C. Clarke's Childhood's End (1953), William Golding's Lord of the Flies (1954) and John Wyndham's The Midwich Cuckoos (1957). It will be argued that the groups of extraordinary children in these novels both tap into newer child-centred assertions about the threats posed by abnormal childhood, underwritten by psychology and psychoanalysis, and represent a reaction to an older progressive tradition in which children were envisaged as the single hope for a utopian future. This article will ultimately assert that the sudden appearance of extraordinary children in science fiction reflects a profound shift in assessment criteria for healthy childhood in Britain from the 1950s onwards, an issue that had become vitally important in a fledgling social democracy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  13. 18 CFR 367.4093 - Account 409.3, Income taxes, extraordinary items.

    Science.gov (United States)

    2010-04-01

    ... NATURAL GAS ACT Income Statement Chart of Accounts Service Company Operating Income § 367.4093 Account 409.3, Income taxes, extraordinary items. This account must include the amount of those local, state and... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Account 409.3, Income...

  14. Extraordinary Measures: Drone Warfare, Securitization, and the “War on Terror”

    Directory of Open Access Journals (Sweden)

    Romaniuk Scott Nicholas

    2015-07-01

    Full Text Available The use of unmanned aerial vehicles or “drones,” as part of the United States’ (US targeted killing (TK program dramatically increased after the War on Terror (WoT was declared. With the ambiguous nature and parameters of the WoT, and stemming from the postulation of numerous low-level, niche-, and other securitizations producing a monolithic threat, US drone operations now constitute a vital stitch in the extensive fabric of US counterterrorism policy. This article employs the theories of securitization and macrosecuritization as discussed by Buzan (1991, 2006, and Buzan and Wæver (2009 to understand targeted killing, by means of weaponized drones, as an extraordinary measure according to the Copenhagen School’s interpretation. An overarching securitization and the use of the “security” label warrants the emergency action of targeted killing through the use of drones as an extraordinary measure. We argue that the WoT serves as a means of securitizing global terrorism as a threat significant enough to warrant the use of drone warfare as an extraordinary use of force. By accepting the WoT as a securitization process we can reasonably accept that the US’ response(s against that threat are also securitized and therefore become extraordinary measures.

  15. Reviews Book: SEP Communications: Transmitting and Receiving Signals Book: Gliding for Gold Book: Radioactivity: A History of a Mysterious Science Book: The New Quantum Age Books: The Art of Science and The Oxford Book of Modern Science Writing Equipment: SEP Analogue/digital transmission unit Equipment: SEP Optical signal transmission set Book: Stars and their Spectra Book: Voicebox: The Physics and Evolution of Speech Web Watch

    Science.gov (United States)

    2012-03-01

    WE RECOMMEND Transmitting and Receiving Signals SEP booklet transmits knowledge The New Quantum Age Understanding modern quantum theory The Art of Science and The Oxford Book of Modern Science Writing Anthologies bring science to life SEP Analogue/digital transmission unit Kit transmits signal between two points SEP Optical signal transmission set Optical kit shows light transmission Stars and their Spectra New book for teaching astrophysics WORTH A LOOK Gliding for Gold Take a journey through the physics of winter sports Radioactivity: A History of a Mysterious Science Book looks at history of radioactivity Voicebox: The Physics and Evolution of Speech TExploring the evolution of the voice WEB WATCH An interactive program with promise?

  16. Force transmissibility versus displacement transmissibility

    Science.gov (United States)

    Lage, Y. E.; Neves, M. M.; Maia, N. M. M.; Tcherniak, D.

    2014-10-01

    It is well-known that when a single-degree-of-freedom (sdof) system is excited by a continuous motion of the foundation, the force transmissibility, relating the force transmitted to the foundation to the applied force, equals the displacement transmissibility. Recent developments in the generalization of the transmissibility to multiple-degree-of-freedom (mdof) systems have shown that similar simple and direct relations between both types of transmissibility do not appear naturally from the definitions, as happens in the sdof case. In this paper, the authors present their studies on the conditions under which it is possible to establish a relation between force transmissibility and displacement transmissibility for mdof systems. As far as the authors are aware, such a relation is not currently found in the literature, which is justified by being based on recent developments in the transmissibility concept for mdof systems. Indeed, it does not appear naturally, but the authors observed that the needed link is present when the displacement transmissibility is obtained between the same coordinates where the applied and reaction forces are considered in the force transmissibility case; this implies that the boundary conditions are not exactly the same and instead follow some rules. This work presents a formal derivation of the explicit relation between the force and displacement transmissibilities for mdof systems, and discusses its potential and limitations. The authors show that it is possible to obtain the displacement transmissibility from measured forces, and the force transmissibility from measured displacements, opening new perspectives, for example, in the identification of applied or transmitted forces. With this novel relation, it becomes possible, for example, to estimate the force transmissibility matrix with the structure off its supports, in free boundary conditions, and without measuring the forces. As far as force identification is concerned, this

  17. Data transmission

    National Research Council Canada - National Science Library

    Tugal, Dogan A; Tugal, Osman

    1989-01-01

    This updated second edition provides working answers to today's critical questions about designing and managing all types of data transmission systems and features a new chapter on local area networks (LANs...

  18. Advanced Silicon Photonic Transceivers - the Case of a Wavelength Division and Polarization Multiplexed Quadrature Phase Shift Keying Receiver for Terabit/s Optical Transmission

    Science.gov (United States)

    2017-03-10

    formats by the co- integration of a passive 90 degree optical hybrid, highspeed balanced Ge photodetectors and a high-speed two-channel transimpedance...40 Gbaud and can handle advanced modulation formats by the co-integration of a passive 90 degree optical hybrid, high- speed balanced Ge...reached at an OSNR of 12.4 dB. The hard -decision FEC (HD-FEC) threshold (BER of 3.8 × 10-3 for 7% overhead) requires 14 dB OSNR. For 16-QAM this requires

  19. Simultaneous 10 Gbps data and polarization-based pulse-per-second clock transmission using a single VCSEL for high-speed optical fibre access networks

    Science.gov (United States)

    Isoe, G. M.; Wassin, S.; Gamatham, R. R. G.; Leitch, A. W. R.; Gibbon, T. B.

    2017-01-01

    Access networks based on vertical cavity surface emitting laser (VCSEL) transmitters offer alternative solution in delivering different high bandwidth, cost effective services to the customer premises. Clock and reference frequency distribution is critical for applications such as Coordinated Universal Time (UTC), GPS, banking and big data science projects. Simultaneous distribution of both data and timing signals over shared infrastructure is thus desirable. In this paper, we propose and experimentally demonstrate a novel, cost-effective technique for multi-signal modulation on a single VCSEL transmitter. Two signal types, an intensity modulated 10 Gbps data signal and a polarization-based pulse per second (PPS) clock signal are directly modulated onto a single VCSEL carrier at 1310 nm. Spectral efficiency is maximized by exploiting inherent orthogonal polarization switching of the VCSEL with changing bias in transmission of the PPS signal. A 10 Gbps VCSEL transmission with PPS over 11 km of G.652 fibre introduced a transmission penalty of 0.52 dB. The contribution of PPS to this penalty was found to be 0.08 dB.

  20. Fabrication of an electro-absorption transceiver with a monolithically integrated optical amplifier for fiber transmission of 40–60 GHz radio signals

    International Nuclear Information System (INIS)

    Zhang, Andy Zhenzhong; Wang, Qin; Fonjallaz, Pierre-Yves; Almqvist, Susanne; Karlsson, Stefan; Kjebon, Olle; Schatz, Richard; Chacinski, Marek; Thylén, Lars; Berggren, Jesper; Hammar, Mattias; Honecker, Jörg; Steffan, Andreas

    2011-01-01

    We report on the fabrication of a monolithically integrated semiconductor optical amplifier (SOA) and a reflective electro-absorption transceiver (EAT) for 40–60 GHz radio-over-fiber applications. The EAT can either function as a transmitter (reflective modulator) or as a receiver (photodetector) depending on operation mode. The SOA and the EAT sections are based on different InGaAsP multiple quantum-well active layers connected by a butt joint. Benzocyclobutene is used to reduce the capacitance beside the ridge mesa. Devices are designed to have a peaked response at the operating frequency through the design of microwave waveguides on top of the devices. The packaged device exhibits at 0.1 mW optical input power an amplified DC responsivity of 18.5 mA mW −1 and a modulation efficiency of 0.67 mW V −1 . The estimated radio frequency loss at 40 GHz of an optical link consisting of two SOA–EAT devices was 23 dB using an unmodulated optical input carrier to the transmitter of 0.94 mW

  1. Fibre-optic communications

    CERN Document Server

    Lecoy, Pierre

    2010-01-01

    This book describes in a comprehensive manner the components and systems of fiber optic communications and networks. The first section explains the theory of multimode and single-mode fibers, then the technological features, including manufacturing, cabling, and connecting. The second section describes the various components (passive and active optical components, integrated optics, opto-electronic transmitters and receivers, and optical amplifiers) used in fiber optic systems. Finally, the optical transmission system design is explained, and applications to optical networks and fiber optic se

  2. Topics in lightwave transmission systems

    CERN Document Server

    Li, Tingye

    1991-01-01

    Topics in Lightwave Transmission Systems is a second volume of a treatise on optical fiber communications that is devoted to the science, engineering, and application of information transmission via optical fibers. The first volume, published in 1985, dealt exclusively with fiber fabrication. The present volume contains topics that pertain to subsystems and systems. The book contains five chapters and begins with discussions of transmitters and receivers, which are basic to systems now operating in the field. Subsequent chapters cover topics relating to coherent systems: frequency and phase m

  3. Transmissions in vehicles 2010

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    method (R.A. Lloyd); (18) Trends of market and technology for agricultural machinery from the view of a vehicle manufacturer (H. Reiter); (19) Shifting comfort improvement on a powershift transmission using objective driveability evaluation (G. Stein); (20) Development trends on construction machinery drive trains (H. Beck); (21) Electrification and hybridisation of powertrains for off-highway machines (M. Mohr); (22) Infinitely variable PTO transmission - Development and test results of an IV-PTO transmission (R. Gugel); (23) Transmission for tractors - requirements, technical solutions and development trends (K. Grad); (24) New hydrostatic-mechanical powersplit CVT-transmission for construction machines (W. Rebholz); (25) AMT today and for the future (M. Hochrein); (26) Efficiency-optimized manual transmission featuring high performance density and excellent shift comfort (J. Patzner); (27) reduction of the gear-rattle noise level of automotive transmissions using innovative gear lubricants (A. Baumann); (28) AWD differential (B.-R. Hoehn); (28) Road-lab-math strategy and implementation in thedevelopment of manual transmission systems (T. Hahne); (29) Fluorescence-based investigations into the contact of wet-disc clutches - Optical investigations into the flat friction contact of multi-disc clutches (N. Weber); (30) The real test drive on the powertrain testbed of maneuver based training (F. Illmeier); (31) Experience of AUTOSAR-compliant development of a power-shift-transmission-control and outlook to future standards including ISO 26262 and EAST-ADL2 - Standards supporting development efficiency (G. Stempfer); (32) The impact of peripheral component on gear development concerning investigation of comfort relevant manoeuvres (A. Albers); (33) Comfort and dynamics of manual gearshifts - definition and experience at the simulator with real-time models for synchronizer and powertrain (U. Schreiber); (34) The eClutch - A new world for manual transmissions (P. Kelly); (35

  4. Electrical transmission

    Energy Technology Data Exchange (ETDEWEB)

    Sayers, D P

    1960-05-01

    After briefly tracing the history of electricity transmission, trends in high voltage transmission and experiments being conducted on 650 kV are discussed. 5000 miles of the U.K. grid are operated at 132 kV and 1000 at 275 kV, ultimately to provide a super grid at 380 kV. Problems are insulation, radio interference and the cost of underground lines (16 times that of overhead lines). Also considered are the economics of the grid as a means of transporting energy and as a means of spreading the peak load over the power stations in the most efficient manner. Finally, the question of amenities is discussed.

  5. A High Gain-Bandwidth Product Distributed Transimpedance Amplifier IC for High-Speed Optical Transmission Using Low-Cost GaAs Technology.

    OpenAIRE

    Giannini, F.; Limiti, E.; Orengo, G.; Serino, A.; De Dominicis, M.

    2002-01-01

    This paper reports a distributed baseband transimpedance amplifier for optical links up to 10 Gb/s. The amplifier operates as a baseband amplifier with a transimpedance gain of 48 dB Ω and a DC-to-9 GHz bandwidth. Some innovative design techniques to improve gain-bandwidth performance at low and high frequency with an available low-cost GaAs MESFET technology have been developed.

  6. Influence of grain size on the extraordinary Hall effect in magnetic granular alloys

    International Nuclear Information System (INIS)

    Granovsky, Alexander B.; Kalitsov, Alan V.; Khanikaev, Alexander B.; Kioussis, Nicholas

    2003-01-01

    A quantum statistical theory of the influence of grain size on the residual extraordinary Hall effect (EHE) in magnetic metal-insulator granular alloys is presented. It is shown that under certain conditions the quasi-classical size-effect (QSE) can lead to similar behaviors of EHE in metal-metal and metal-insulator alloys. The possible dependences of EHE coefficient on the grain size and the role of the QSE in the giant EHE in nanocomposites are discussed

  7. Influence of grain size on the extraordinary Hall effect in magnetic granular alloys

    Energy Technology Data Exchange (ETDEWEB)

    Granovsky, Alexander B. E-mail: granov@magn.ru; Kalitsov, Alan V.; Khanikaev, Alexander B.; Kioussis, Nicholas

    2003-03-01

    A quantum statistical theory of the influence of grain size on the residual extraordinary Hall effect (EHE) in magnetic metal-insulator granular alloys is presented. It is shown that under certain conditions the quasi-classical size-effect (QSE) can lead to similar behaviors of EHE in metal-metal and metal-insulator alloys. The possible dependences of EHE coefficient on the grain size and the role of the QSE in the giant EHE in nanocomposites are discussed.

  8. The Concept of Extraordinary Crime in Indonesia Legal System: is the Concept an Effective Criminal Policy?

    OpenAIRE

    Prahassacitta, Vidya

    2016-01-01

    The concept of extraordinary crime was a common concept in Indonesia. Adopts from the concept of the most serious crime in Rome Statute and adjusted with the Indonesian legal system. Then it developed wider and introduced into terrorism, corruption, drug abuse offenses, and child sexual abuse in legislations and Constitutional Court verdicts. The implementation of this concept generated some consequences in drafting and formulating the legislation as part of penal policy. This leads to two le...

  9. The savant syndrome: an extraordinary condition. A synopsis: past, present, future

    OpenAIRE

    Treffert, Darold A.

    2009-01-01

    Savant syndrome is a rare, but extraordinary, condition in which persons with serious mental disabilities, including autistic disorder, have some ‘island of genius’ which stands in marked, incongruous contrast to overall handicap. As many as one in 10 persons with autistic disorder have such remarkable abilities in varying degrees, although savant syndrome occurs in other developmental disabilities or in other types of central nervous system injury or disease as well. Whatever the particular ...

  10. Extraordinary results

    International Nuclear Information System (INIS)

    Cicova, V.

    2012-01-01

    For the first time in the history, Slovenske elektrarne became the first winner in a new category Business and Biodiversity in the competition of European companies aimed at the environment protection. Excellent results were achieved by a long-term co-operation with the Tatras National Park, in particular in saving the endangered animals.

  11. Extraordinary Sportswomen

    DEFF Research Database (Denmark)

    As in many other fields, in sports too, women were latecomers and considered as the ‘other sex’ – at least until the twenty-first century. When sport developed in its modern forms towards the second half of the nineteenth century, women were (and to a certain degree still are) considered too weak......, which strategies did they apply and how did they fight and win their battles against the gender order of their time? The chapters were originally published as a special issue of Sport in Society.......As in many other fields, in sports too, women were latecomers and considered as the ‘other sex’ – at least until the twenty-first century. When sport developed in its modern forms towards the second half of the nineteenth century, women were (and to a certain degree still are) considered too weak...... to participate in strenuous physical activities, and were thus excluded from various sports, competitions and events. Although they gradually gained access to all sports, competitive sport was – and is still today – one of the few areas in modern societies with strict gender segregation: in most sports, men do...

  12. Extraordinary Tales

    Indian Academy of Sciences (India)

    IAS Admin

    are protozoa, plants, fungi and animals. Parasitology refers to the study of ... this parasite infect us if we are optional in its lifecycle? Of course, this aids in the ... unclean fruits and vegetables that might have been contaminated with cat faeces.

  13. On Not Understanding Extraordinary Language in the Buddhist Tantra of Japan

    Directory of Open Access Journals (Sweden)

    Richard K. Payne

    2017-10-01

    Full Text Available The question motivating this essay is how tantric Buddhist practitioners in Japan understood language such as to believe that mantra, dhāraṇī, and related forms are efficacious. “Extraordinary language” is introduced as a cover term for these several similar language uses found in tantric Buddhist practices in Japan. The essay proceeds to a critical examination of Anglo-American philosophy of language to determine whether the concepts, categories, and concerns of that field can contribute to the analysis and understanding of extraordinary language. However, that philosophy of language does not contribute to this analysis, as it is constrained by its continuing focus on its founding concepts, dating particularly from the work of Frege. Comparing it to Indic thought regarding language reveals a distinct mismatch, further indicating the limiting character of the philosophy of language. The analysis then turns to examine two other explanations of tantric language use found in religious studies literature: magical language and performative language. These also, however, prove to be unhelpful. While the essay is primarily critical, one candidate for future constructive study is historical pragmatics, as suggested by Ronald Davidson. The central place of extraordinary language indicates that Indic reflections on the nature of language informed tantric Buddhist practice in Japan and are not simply cultural baggage.

  14. Soft optics in intelligent optical networks

    Science.gov (United States)

    Shue, Chikong; Cao, Yang

    2001-10-01

    In addition to the recent advances in Hard-optics that pushes the optical transmission speed, distance, wave density and optical switching capacity, Soft-optics provides the necessary intelligence and control software that reduces operational costs, increase efficiency, and enhances revenue generating services by automating optimal optical circuit placement and restoration, and enabling value-added new services like Optical VPN. This paper describes the advances in 1) Overall Hard-optics and Soft-optics 2) Layered hierarchy of Soft-optics 3) Component of Soft-optics, including hard-optics drivers, Management Soft-optics, Routing Soft-optics and System Soft-optics 4) Key component of Routing and System Soft-optics, namely optical routing and signaling (including UNI/NNI and GMPLS signaling). In summary, the soft-optics on a new generation of OXC's enables Intelligent Optical Networks to provide just-in-time service delivery and fast restoration, and real-time capacity management that eliminates stranded bandwidth. It reduces operational costs and provides new revenue opportunities.

  15. LO-TO splittings, effective charges and interactions in electro-optic meta-nitroaniline crystal as studied by polarized IR reflection and transmission spectra

    Science.gov (United States)

    Szostak, M. M.; Le Calvé, N.; Romain, F.; Pasquier, B.

    1994-10-01

    The polarized IR reflection spectra of the meta-nitroaniline ( m-NA) single crystal along the a, b and c crystallographic axes as well as the b and c polarized transmission spectra have been measured in the 100-400 cm -1 region. The LO-TO splitting values have been calculated from the reflection spectra by fitting them with the four parameter dielectric function. The dipole moment derivatives, relevant to dynamic effective charges, of the vibrations have also been calculated and used to check the applicability of the oriented gas model (OGM) to reflection spectra. The discrepancies from the OGM have been discussed in terms of vibronic couplings, weak hydrogen bondings (HB) and intramolecular charge transfer.

  16. Real-Time Video Transmission Over Different Underwater Wireless Optical Channels Using a Directly Modulated 520  nm Laser Diode

    KAUST Repository

    Al-Halafi, Abdullah; Oubei, Hassan M.; Ooi, Boon S.; Shihada, Basem

    2017-01-01

    We experimentally demonstrate high-quality real-time video streaming over an underwater wireless optical communication (UWOC) link up to 5 m distance using phase-shift keying (PSK) modulation and quadrature amplitude modulation (QAM) schemes. The communication system uses software defined platforms connected to a commercial TO-9 packaged pigtailed 520 nm directly modulated laser diode (LD) with 1.2 GHz bandwidth as the optical transmitter and an avalanche photodiode (APD) module as the receiver. To simulate various underwater channels, we perform laboratory experiments on clear, coastal, harbor I, and harbor II ocean water types. The measured bit error rates of the received video streams are 1.0×10−9 for QPSK, 4-QAM, and 8-QAM and 9.9×10−9 for 8-PSK. We further evaluate the quality of the received live video images using structural similarity and achieve values of about 0.9 for the first three water types, and about 0.7 for harbor II. To the best of our knowledge, these results present the highest quality video streaming ever achieved in UWOC systems that resemble communication channels in real ocean water environments.

  17. Real-Time Video Transmission Over Different Underwater Wireless Optical Channels Using a Directly Modulated 520  nm Laser Diode

    KAUST Repository

    Al-Halafi, Abdullah

    2017-09-13

    We experimentally demonstrate high-quality real-time video streaming over an underwater wireless optical communication (UWOC) link up to 5 m distance using phase-shift keying (PSK) modulation and quadrature amplitude modulation (QAM) schemes. The communication system uses software defined platforms connected to a commercial TO-9 packaged pigtailed 520 nm directly modulated laser diode (LD) with 1.2 GHz bandwidth as the optical transmitter and an avalanche photodiode (APD) module as the receiver. To simulate various underwater channels, we perform laboratory experiments on clear, coastal, harbor I, and harbor II ocean water types. The measured bit error rates of the received video streams are 1.0×10−9 for QPSK, 4-QAM, and 8-QAM and 9.9×10−9 for 8-PSK. We further evaluate the quality of the received live video images using structural similarity and achieve values of about 0.9 for the first three water types, and about 0.7 for harbor II. To the best of our knowledge, these results present the highest quality video streaming ever achieved in UWOC systems that resemble communication channels in real ocean water environments.

  18. Transmission analysis in WDM networks

    DEFF Research Database (Denmark)

    Rasmussen, Christian Jørgen

    1999-01-01

    This thesis describes the development of a computer-based simulator for transmission analysis in optical wavelength division multiplexing networks. A great part of the work concerns fundamental optical network simulator issues. Among these issues are identification of the versatility and user...... the different component models are invoked during the simulation of a system. A simple set of rules which makes it possible to simulate any network architectures is laid down. The modelling of the nonlinear fibre and the optical receiver is also treated. The work on the fibre concerns the numerical solution...

  19. Electron cyclotron waves transmission: new approach for the characterization of electron distribution functions in Tokamak hot plasmas; La transmission d`ondes cyclotroniques electroniques: une approche nouvelle pour caracteriser les fonctions de distribution electronique des plasmas chauds de Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Michelot, Y

    1995-10-01

    Fast electrons are one of the basic ingredients of plasma operations in many existing thermonuclear fusion research devices. However, the understanding of fast electrons dynamics during creation and sustainment of the superthermal electrons tail is far for being satisfactory. For this reason, the Electron Cyclotron Transmission (ECT) diagnostic was implemented on Tore Supra tokamak. It consists on a microwave transmission system installed on a vertical chord crossing the plasma center and working in the frequency range 77-109 GHz. Variations of the wave amplitude during the propagation across the plasma may be due to refraction and resonant absorption. For the ECT, the most common manifestation of refraction is a reduction of the received power density with respect to the signal detected in vacuum, due to the spreading and deflection of the wave beam. Wave absorption is observed in the vicinity of the electron cyclotron harmonics and may be due both to thermal plasma and to superthermal electron tails. It has a characteristic frequency dependence due to the relativistic mass variation in the wave-electron resonance condition. This thesis presents the first measurements of: the extraordinary mode optical depth at the third harmonics, the electron temperature from the width of a cyclotron absorption line and the relaxation times of the electron distribution during lower hybrid current drive from the ordinary mode spectral superthermal absorption line at the first harmonic. (J.S.). 175 refs., 110 figs., 9 tabs., 3 annexes.

  20. Nearly zero transmission through periodically modulated ultrathin metal films

    DEFF Research Database (Denmark)

    Xiao, Sanshui; Zhang, Jingjing; Peng, Liang

    2010-01-01

    Transmission of light through an optically ultrathin metal film with a thickness comparable to its skin depth is significant. We demonstrate experimentally nearly-zero transmission of light through a film periodically modulated by a one-dimensional array of subwavelength slits. The suppressed...... optical transmission is due to the excitation of surface plasmon polaritons and the zero-transmission phenomenon is strongly dependent on the polarization of the incident wave....

  1. Electron cyclotron waves transmission: new approach for the characterization of electron distribution functions in Tokamak hot plasmas

    International Nuclear Information System (INIS)

    Michelot, Y.

    1995-10-01

    Fast electrons are one of the basic ingredients of plasma operations in many existing thermonuclear fusion research devices. However, the understanding of fast electrons dynamics during creation and sustainment of the superthermal electrons tail is far for being satisfactory. For this reason, the Electron Cyclotron Transmission (ECT) diagnostic was implemented on Tore Supra tokamak. It consists on a microwave transmission system installed on a vertical chord crossing the plasma center and working in the frequency range 77-109 GHz. Variations of the wave amplitude during the propagation across the plasma may be due to refraction and resonant absorption. For the ECT, the most common manifestation of refraction is a reduction of the received power density with respect to the signal detected in vacuum, due to the spreading and deflection of the wave beam. Wave absorption is observed in the vicinity of the electron cyclotron harmonics and may be due both to thermal plasma and to superthermal electron tails. It has a characteristic frequency dependence due to the relativistic mass variation in the wave-electron resonance condition. This thesis presents the first measurements of: the extraordinary mode optical depth at the third harmonics, the electron temperature from the width of a cyclotron absorption line and the relaxation times of the electron distribution during lower hybrid current drive from the ordinary mode spectral superthermal absorption line at the first harmonic. (J.S.). 175 refs., 110 figs., 9 tabs., 3 annexes

  2. Transmission Electron Microscopy of the Textured Silver Back Reflector of a Thin Film Silicon Solar Cell: From Crystallography to Optical Absorption

    DEFF Research Database (Denmark)

    Duchamp, Martial; Söderström, K.; Jeangros, Q.

    2011-01-01

    The study of light trapping in amorphous, microcrystalline and micromorph thin-film Si solar cells is an important and active field of investigation. It has been demonstrated that the use of a rough Ag back-reflector lead to an increase of short circuit current but also to losses through...... the creation of surface plasmon polaritons. Here, we use transmission electron microscopy (TEM) techniques to study the grain structure of a Ag thin-film that was sputtered on top of 2-μm-thick rough ZnO layer - defects, such as twin-boundaries have been observed. A smoothing of the top Ag surface was also...... observed after ex-situ annealing. Electron energy-loss spectroscopy with a monochromatic beam was used to measure the surface plasmon resonance with nm spatial resolution. 1 eV and 3 eV Ag surface plasmon resonances have been observed on as-grown layers. Such measurements provide valuable information about...

  3. Exploiting a Transmission Grating Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ronald E. Bell

    2004-12-08

    The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics.

  4. Exploiting a Transmission Grating Spectrometer

    International Nuclear Information System (INIS)

    Bell, Ronald E.

    2004-01-01

    The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics

  5. Diffractive centrosymmetric 3D-transmission phase gratings positioned at the image plane of optical systems transform lightlike 4D-WORLD as tunable resonators into spectral metrics...

    Science.gov (United States)

    Lauinger, Norbert

    1999-08-01

    Diffractive 3D phase gratings of spherical scatterers dense in hexagonal packing geometry represent adaptively tunable 4D-spatiotemporal filters with trichromatic resonance in visible spectrum. They are described in the (lambda) - chromatic and the reciprocal (nu) -aspects by reciprocal geometric translations of the lightlike Pythagoras theorem, and by the direction cosine for double cones. The most elementary resonance condition in the lightlike Pythagoras theorem is given by the transformation of the grating constants gx, gy, gz of the hexagonal 3D grating to (lambda) h1h2h3 equals (lambda) 111 with cos (alpha) equals 0.5. Through normalization of the chromaticity in the von Laue-interferences to (lambda) 111, the (nu) (lambda) equals (lambda) h1h2h3/(lambda) 111-factor of phase velocity becomes the crucial resonance factor, the 'regulating device' of the spatiotemporal interaction between 3D grating and light, space and time. In the reciprocal space equal/unequal weights and times in spectral metrics result at positions of interference maxima defined by hyperbolas and circles. A database becomes built up by optical interference for trichromatic image preprocessing, motion detection in vector space, multiple range data analysis, patchwide multiple correlations in the spatial frequency spectrum, etc.

  6. Does a leaf absorb radiation in the near infrared (780-900 nm) region? A new approach to quantifying optical reflection, absorption and transmission of leaves.

    Science.gov (United States)

    Merzlyak, Mark N; Chivkunova, Olga B; Melø, T B; Naqvi, K Razi

    2002-01-01

    The following question is addressed here: do healthy leaves absorb, as the spectra published over the last 50 years indicate, some 5-20% of incident radiation in the 780-900 nm region? The answer is found to be negative, and previous findings result from incomplete collection of the transmitted light by the detection system (even when the leaf is placed next to, but outside, the entrance port of an integrating sphere). A simple remedy for this inherent flaw in the experimental arrangement is applied successfully to leaves (of 10 unrelated species) differing in thickness, age and pigment content. The study has shown that, from an optical standpoint, a leaf tissue is a highly scattering material, and the infinite reflectance of a leaf is exceedingly sensitive to trace amounts of absorbing components. It is shown that water contributes, in a thick leaf (Kalanchoe blossfeldiana), an easily detectable signal even in the 780-900 nm region. The practical benefits resulting from improved measurements of leaf spectra are pointed out.

  7. Multi-frequency acoustic metasurface for extraordinary reflection and sound focusing

    Directory of Open Access Journals (Sweden)

    Yi-Fan Zhu

    2016-12-01

    Full Text Available We theoretically and numerically present the design of multi-frequency acoustic metasurfaces (MFAMs with simple structure that can work not only at fundamental frequency, but also at their harmonic frequencies, which breaks the single frequency limitation in conventional resonance-based acoustic metasurfaces. The phase matched condition for achromatic manipulation is discussed. We demonstrate achromatic extraordinary reflection and sound focusing at 1700Hz, 3400Hz, and 5100Hz, that is, they have the same reflection direction and the same focusing position. This significant feature may pave the way to new type of acoustic metasurface, and will also extend acoustic metasurface applications to strongly nonlinear source cases.

  8. The savant syndrome: an extraordinary condition. A synopsis: past, present, future.

    Science.gov (United States)

    Treffert, Darold A

    2009-05-27

    Savant syndrome is a rare, but extraordinary, condition in which persons with serious mental disabilities, including autistic disorder, have some 'island of genius' which stands in marked, incongruous contrast to overall handicap. As many as one in 10 persons with autistic disorder have such remarkable abilities in varying degrees, although savant syndrome occurs in other developmental disabilities or in other types of central nervous system injury or disease as well. Whatever the particular savant skill, it is always linked to massive memory. This paper presents a brief review of the phenomenology of savant skills, the history of the concept and implications for education and future research.

  9. A top-contacted extraordinary magnetoresistance sensor fabricated with an unpatterned semiconductor epilayer

    KAUST Repository

    Sun, Jian

    2013-04-01

    An extraordinary magnetoresistance device is developed from an unpatterned semiconductor epilayer onto which the metal contacts are fabricated. Compared with conventionally fabricated devices, for which semiconductor patterning and precise alignment are required, this design is not only easier from a technological point of view, but it also has the potential to reduce damage introduced to the semiconductor during fabrication. The device shows a similar magnetoresistance ratio as a conventional one but it has a lower sensitivity. Because of the reduced resistance, and hence less noise, high magnetic field resolution is maintained. © 1980-2012 IEEE.

  10. On the dispersion characteristics of extraordinary mode in a relativistic fully degenerate electron plasma

    Science.gov (United States)

    Noureen, S.; Abbas, G.; Sarfraz, M.

    2018-01-01

    The study of relativistic degenerate plasmas is important in many astrophysical and laboratory environments. Using linearized relativistic Vlasov-Maxwell equations, a generalized expression for the plasma conductivity tensor is derived. Employing Fermi-Dirac distribution at zero temperature, the dispersion relation of the extraordinary mode in a relativistic degenerate electron plasma is investigated. The propagation characteristics are examined in different relativistic density ranges. The shifting of cutoff points due to relativistic effects is observed analytically and graphically. Non-relativistic and ultra-relativistic limiting cases are also presented.

  11. Strong temperature dependence of extraordinary magnetoresistance correlated to mobility in a two-contact device

    KAUST Repository

    Sun, Jian

    2012-02-21

    A two-contact extraordinary magnetoresistance (EMR) device has been fabricated and characterized at various temperatures under magnetic fields applied in different directions. Large performance variations across the temperature range have been found, which are due to the strong dependence of the EMR effect on the mobility. The device shows the highest sensitivity of 562ω/T at 75 K with the field applied perpendicularly. Due to the overlap between the semiconductor and the metal shunt, the device is also sensitive to planar fields but with a lower sensitivity of about 20 to 25% of the one to perpendicular fields. © 2012 The Japan Society of Applied Physics.

  12. A quasi-optical and corrugated waveguide microwave transmission system for simultaneous dynamic nuclear polarization NMR on two separate 14.1 T spectrometers

    Science.gov (United States)

    Dubroca, Thierry; Smith, Adam N.; Pike, Kevin J.; Froud, Stuart; Wylde, Richard; Trociewitz, Bianca; McKay, Johannes; Mentink-Vigier, Frederic; van Tol, Johan; Wi, Sungsool; Brey, William; Long, Joanna R.; Frydman, Lucio; Hill, Stephen

    2018-04-01

    Nuclear magnetic resonance (NMR) is an intrinsically insensitive technique, with Boltzmann distributions of nuclear spin states on the order of parts per million in conventional magnetic fields. To overcome this limitation, dynamic nuclear polarization (DNP) can be used to gain up to three orders of magnitude in signal enhancement, which can decrease experimental time by up to six orders of magnitude. In DNP experiments, nuclear spin polarization is enhanced by transferring the relatively larger electron polarization to NMR active nuclei via microwave irradiation. Here, we describe the design and performance of a quasi-optical system enabling the use of a single 395 GHz gyrotron microwave source to simultaneously perform DNP experiments on two different 14.1 T (1H 600 MHz) NMR spectrometers: one configured for magic angle spinning (MAS) solid state NMR; the other configured for solution state NMR experiments. In particular, we describe how the high power microwave beam is split, transmitted, and manipulated between the two spectrometers. A 13C enhancement of 128 is achieved via the cross effect for alanine, using the nitroxide biradical AMUPol, under MAS-DNP conditions at 110 K, while a 31P enhancement of 160 is achieved via the Overhauser effect for triphenylphosphine using the monoradical BDPA under solution NMR conditions at room temperature. The latter result is the first demonstration of Overhauser DNP in the solution state at a field of 14.1 T (1H 600 MHz). Moreover these results have been produced with large sample volumes (∼100 μL, i.e. 3 mm diameter NMR tubes).

  13. A quasi-optical and corrugated waveguide microwave transmission system for simultaneous dynamic nuclear polarization NMR on two separate 14.1 T spectrometers.

    Science.gov (United States)

    Dubroca, Thierry; Smith, Adam N; Pike, Kevin J; Froud, Stuart; Wylde, Richard; Trociewitz, Bianca; McKay, Johannes; Mentink-Vigier, Frederic; van Tol, Johan; Wi, Sungsool; Brey, William; Long, Joanna R; Frydman, Lucio; Hill, Stephen

    2018-04-01

    Nuclear magnetic resonance (NMR) is an intrinsically insensitive technique, with Boltzmann distributions of nuclear spin states on the order of parts per million in conventional magnetic fields. To overcome this limitation, dynamic nuclear polarization (DNP) can be used to gain up to three orders of magnitude in signal enhancement, which can decrease experimental time by up to six orders of magnitude. In DNP experiments, nuclear spin polarization is enhanced by transferring the relatively larger electron polarization to NMR active nuclei via microwave irradiation. Here, we describe the design and performance of a quasi-optical system enabling the use of a single 395 GHz gyrotron microwave source to simultaneously perform DNP experiments on two different 14.1 T ( 1 H 600 MHz) NMR spectrometers: one configured for magic angle spinning (MAS) solid state NMR; the other configured for solution state NMR experiments. In particular, we describe how the high power microwave beam is split, transmitted, and manipulated between the two spectrometers. A 13 C enhancement of 128 is achieved via the cross effect for alanine, using the nitroxide biradical AMUPol, under MAS-DNP conditions at 110 K, while a 31 P enhancement of 160 is achieved via the Overhauser effect for triphenylphosphine using the monoradical BDPA under solution NMR conditions at room temperature. The latter result is the first demonstration of Overhauser DNP in the solution state at a field of 14.1 T ( 1 H 600 MHz). Moreover these results have been produced with large sample volumes (∼100 µL, i.e. 3 mm diameter NMR tubes). Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Enhancement of the transverse magneto-optical Kerr effect via resonant tunneling in trilayers containing magneto-optical metals

    Energy Technology Data Exchange (ETDEWEB)

    Girón-Sedas, J. A. [Departamento de Física, Universidad del Valle, AA 25360, Cali (Colombia); Centro de Investigación e Innovación en Bioinformática y Fotónica - CIBioFI, AA 25360 Cali (Colombia); Mejía-Salazar, J. R., E-mail: jrmejia3146@gmail.com [Instituto de Física de São Carlos, Universidade de São Paulo, CP 369, 13560-970 São Carlos, SP (Brazil); Moncada-Villa, E.; Porras-Montenegro, N. [Departamento de Física, Universidad del Valle, AA 25360, Cali (Colombia)

    2016-07-18

    We propose a way to enhance the transverse magneto-optical Kerr effect, by the excitation of resonant tunneling modes, in subwavelength trilayer structures featuring a dielectric slab sandwiched between two magneto-optical metallic layers. Depending on the magneto-optical layer widths, the proposed system may exhibit an extraordinary transverse magneto-optical Kerr effect, which makes it very attractive for the design and engineering of thin-film magneto-optical-based devices for future photonic circuits or fiber optical-communication systems.

  15. Absorber transmissivities in 57Fe Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Ballet, O.

    1985-01-01

    Some useful relations are derived for the polarization dependent optical index of 57 Fe Moessbauer absorbers. Real rotation matrices are extensively used and, besides wave-direction dependence, their properties simplify also the treatment of texture and f-anisotropy. The derivation of absorber transmissivities from the optical index is discussed with a special emphasis on line overlapping. (Auth.)

  16. Transcending Transmission

    DEFF Research Database (Denmark)

    Schoeneborn, Dennis; Trittin, Hannah

    2013-01-01

    Purpose – Extant research on corporate social responsibility (CSR) communication primarily relies on a transmission model of communication that treats organizations and communication as distinct phenomena. This approach has been criticized for neglecting the formative role of communication...... in the emergence of organizations. This paper seeks to propose to reconceptualize CSR communication by drawing on the “communication constitutes organizations” (CCO) perspective. Design/methodology/approach – This is a conceptual paper that explores the implications of switching from an instrumental...... to a constitutive notion of communication. Findings – The study brings forth four main findings: from the CCO view, organizations are constituted by several, partly dissonant, and potentially contradictory communicative practices. From that viewpoint, the potential impact of CSR communication becomes a matter...

  17. Survivability Research of Power Optical Transmission Network based on Complex Network%基于复杂网络的电力光传输网生存性研究

    Institute of Scientific and Technical Information of China (English)

    夏正云; 孙娜; 施建强; 黄明明

    2017-01-01

    电力光传输网是服务于电力系统的通信专网,其生存性高低对电力系统安全、稳定运行至关重要.首先,基于复杂网络理论给出网络生存性的定义;其次,从最短路径选择和基于平均距离的拓扑优化两个方面作为研究切入点研究网络生存性,最短路径的选择可以有效减少网络拥塞发生的概率,基于平均距离的拓扑优化可以减小网络均距,提高网络的传输效率;最后,结合A市电力光传输网东北环实例,从最短路径选择和拓扑优化两方面分析整个东北环网的生存能力.这对保障电网系统安全可靠运行、降低大规模电网事故的发生具有十分重要的意义.%Power optical transmission network is a communication private network serving electric power system. Its survivability is crucial to the security and stability of power system. First of all, the definition of network survivability is given based on complex network theory. Secondly, the network survivability is studied from two aspects: the shortest path selection and the topology optimization based on the average distance. The selection of the shortest path can effectively reduce the probability of network congestion. Topology optimization based on average distance can reduce the average distance of the network and improve the transmission efficiency. Finally, combining with the northeast ring of A city power transmission network, the survivability of the whole northeast ring network is analyzed from two aspects of the shortest path selection and topology optimization. This is of great significance to ensure the safe and reliable operation of power grid system and reduce the occurrence of large-scale power grid accidents.

  18. Newton's Contributions to Optics

    Indian Academy of Sciences (India)

    creativity is apparent, even in ideas and models in optics that were ... Around Newton's time, a number of leading figures in science ..... successive circles increased as integers, i.e. d increases by inte- ... of easy reflections and transmission".

  19. Misfitting and Hater Blocking: A Feminist Disability Analysis of the Extraordinary Body on Reality Television

    Directory of Open Access Journals (Sweden)

    Krystal Cleary

    2016-12-01

    Full Text Available This article analyzes three popular TLC programs that are emblematic of contemporary reality televisual representations of the extraordinary body: Abby & Brittany (2012, The Little Couple (2009-, and My Big Fat Fabulous Life (2015-. Extending Rosemarie Garland-Thomson's concept of "misfitting," I demonstrate how the non-normative body fits seamlessly into the mediated domain of reality television precisely because of its misfit in material and social spheres. The representational mode of these programs appears as a corrective to oppressive depictions of people with non-normative bodies, yet, I argue, the discourse of extraordinary normalcy built into the narrative framework of these programs is in fact supported by a scaffolding of normativizing logics that hinge upon casts members' whiteness, upward class mobility, and fulfillment of conventional gender and sexual norms. As such, I examine how specific bodies–heterosexual, white, gender normative, affluent–are called upon to perform disability on reality television. I assert that these programs dangerously depoliticize disability by narratively isolating it from other facets of identity and power, and furthermore regard ableism as an individual and moralistic matter perpetuated by antagonistic "haters" rather than a concern of the State.

  20. Extraordinary tunable dynamic range of electrochemical aptasensor for accurate detection of ochratoxin A in food samples

    Directory of Open Access Journals (Sweden)

    Lin Cheng

    2017-06-01

    Full Text Available We report the design of a sensitive, electrochemical aptasensor for detection of ochratoxin A (OTA with an extraordinary tunable dynamic sensing range. This electrochemical aptasensor is constructed based on the target induced aptamer-folding detection mechanism and the recognition between OTA and its aptamers results in the conformational change of the aptamer probe and thus signal changes for measurement. The dynamic sensing range of the electrochemical aptasensor is successfully tuned by introduction of free assistant aptamer probes in the sensing system. Our electrochemical aptasensor shows an extraordinary dynamic sensing range of 11-order magnitude of OTA concentration from 10−8 to 102 ng/g. Of great significance, the signal response in all OTA concentration ranges is at the same current scale, demonstrating that our sensing protocol in this research could be applied for accurate detections of OTA in a broad range without using any complicated treatment of signal amplification. Finally, OTA spiked red wine and maize samples in different dynamic sensing ranges are determined with the electrochemical aptasensor under optimized sensing conditions. This tuning strategy of dynamic sensing range may offer a promising platform for electrochemical aptasensor optimizations in practical applications.