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Author Jiang, Leaf A.; Luu, Jane X.
Title Heterodyne detection with a weak local oscillator Type Journal Article
Year 2008 Publication Appl. Opt. Abbreviated Journal Appl. Opt.
Volume 47 Issue (down) 10 Pages 1486-1503
Keywords weak local oscillator, weak LO, photon-counting detector, photon-counting mixer, counter detector, counter mixer, PD mixer, PCD mixer
Abstract eterodyne detection in the limit of weak (a few photons) local oscillator and signal power levels has been largely neglected in the past, as authors almost always assumed that the noise was dominated by the shot noise from a strong local oscillator. We present the theory for heterodyne detection of diffuse and specular targets at arbitrary power levels, including the case where the local oscillator power is only a few photons per coherent integration period. The theory was tested with experimental results, and was found to show good agreement. We show how to interpret the power spectral density of the heterodyne signal and how to determine the optimal number of signal and local oscillator photons per coherent integration.
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Notes Approved no
Call Number Serial 979
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Author Semenov, A. V.; Devyatov, I. A.; Ryabchun, S. A.; Maslennikov, S. N.; Maslennikova, A. S.; Larionov, P. A.; Voronov, B. M.; Chulkova, G. M.
Title Absorption of terahertz electromagnetic radiation in dirty superconducting film at arbitrary type of the spectral functions Type Journal Article
Year 2011 Publication Rus. J. Radio Electron. Abbreviated Journal Rus. J. Radio Electron.
Volume Issue (down) 10 Pages
Keywords terahertz electromagnetic radiation; superconductors; detectors of terahertz range
Abstract A problem of absorption of high-frequency electromagnetic field in dirty superconductor is treated within Keldysh technic. Expression for the source term in the kinetic equation for quasiparticle distribution function is derived. The result is significant for deriving a consistent microscopic theory of superconducting detectors for terahertz frequency range, perspective detectors on kinetic inductance of current-biased superconducting strip and on Josephson inductance of tunnel.
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Notes 7 pages Approved no
Call Number Serial 1117
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Author Lieberzeit, P.; Afzal, A.; Rehman, A.; Dickert, F.
Title Nanoparticles for detecting pollutants and degradation processes with mass-sensitive sensors Type Journal Article
Year 2007 Publication Sensors and Actuators B: Chemical Abbreviated Journal Sensors and Actuators B: Chemical
Volume 127 Issue (down) 1 Pages 132-136
Keywords molecular imprinted polymer, MIP, recognition, quartz crystal microbalance, QCM, mass-sensitive sensor, detector
Abstract Compared with thin films, nanoparticle layers as coatings for QCM offer substantially increased interaction areas and sensitivities with favourable response times. Molybdenum disulphide (MoS2), e.g. has turned out to be a highly suitable material for interacting with thiols. The resulting materials are sufficiently soft according to Pearson to bind sulphur containing compounds reversibly. Depositing MoS2 nanoparticle submonolayers (particle size 200–300 nm) leads to an increase in sensor response by a factor of ten compared to a pure gold layer. Additionally, the nanoparticle layers show fully reversible sensor signals. Particle synthesis can also be combined with the molecular imprinting approach: by a precipitation technique, it is possible to generate molecularly imprinted TiO2 particles for engine oil degradation measurements. Compared with deposited thin layers, particles incorporate oxidised compounds from lubricants by a factor of two better.
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ISSN 0925-4005 ISBN Medium
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Notes Approved no
Call Number Serial 568
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Author Шангина, Е. Л.; Смирнов, К. В.; Морозов, Д. В.; Ковалюк, В. В.; Гольцман, Г. Н.; Веревкин, А. А.; Торопов, А. И.
Title Концентрационная зависимость полосы преобразования смесителей субмиллиметрового диапазона на основе наноструктур AlGaAs/GaAs Type Journal Article
Year 2010 Publication Изв. РАН Сер. Физ. Abbreviated Journal Изв. РАН Сер. Физ.
Volume 74 Issue (down) 1 Pages 110-112
Keywords 2DEG AlGaAs/GaAs heterostructures, THz heterodyne detectors, IF bandwidth
Abstract Методом субмиллиметровой спектроскопии с высоким временным разрешением при Т = 4.2 К измерена концентрационная зависимость полосы преобразования гетеродинного детектирования гетероструктур AlGaAs/GaAs с двумерным электронным газом. С увеличением концентрации двумерных электронов ns = (1.6–6.6) · 1011см-2 ширина полосы преобразования f3dB уменьшается от 245 до 145 МГц. В исследованной области концентраций наблюдается зависимость f3dB , обусловленная рассеянием электронов на деформационном потенциале акустических фононов и пьезоэлектрическим рассеянием.
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Language Russian Summary Language Original Title
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Notes Duplicated as 1217 Approved no
Call Number RPLAB @ gujma @ Serial 642
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Author Mitin, Vladimir; Antipov, Andrei; Sergeev, Andrei; Vagidov, Nizami; Eason, David; Strasser, Gottfried
Title Quantum Dot Infrared Photodetectors: Photoresponse Enhancement Due to Potential Barriers Type Journal Article
Year 2011 Publication Nanoscale Research Letters Abbreviated Journal Nanoscale res lett
Volume 6 Issue (down) 1 Pages 6
Keywords Quantum dots; Infrared detectors; Photoresponse; Doping; Potential barriers; Capture processes
Abstract Potential barriers around quantum dots (QDs) play a key role in kinetics of photoelectrons. These barriers are always created, when electrons from dopants outside QDs fill the dots. Potential barriers suppress the capture processes of photoelectrons and increase the photoresponse. To directly investigate the effect of potential barriers on photoelectron kinetics, we fabricated several QD structures with different positions of dopants and various levels of doping. The potential barriers as a function of doping and dopant positions have been determined using nextnano3 software. We experimentally investigated the photoresponse to IR radiation as a function of the radiation frequency and voltage bias. We also measured the dark current in these QD structures. Our investigations show that the photoresponse increases ~30 times as the height of potential barriers changes from 30 to 130 meV.
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Notes Approved no
Call Number RPLAB @ gujma @ Serial 712
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