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Author Iomdina, E. N.; Seliverstov, S.; Sianosyan, A.; Teplyakova, K.; Rusova, A.; Goltsman, G. url  doi
openurl 
  Title The prospects of using the radiation for the assessment of corneal and scleral hydration Type Abstract
  Year (down) 2016 Publication Acta Ophthalmol. Abbreviated Journal Acta Ophthalmol.  
  Volume 94 Issue Pages  
  Keywords BWO, avalanche transit‐time diode, medicine, biology  
  Abstract Purpose

An adequate water balance (hydration extent) is one of the basic factors of normal eye function, including its external shells – the cornea and the sclera. THz systems creating images in reflected beams are likely to become ideal instruments of noninvasive testing of corneal and scleral hydration degree as THz radiation is highly sensitive to water content. The paper aims at studying the transmittance and reflectance spectra of the cornea and the sclera of rabbit and human eyes, as well as those of the whole rabbit eye, in the frequency range of 0.13–0.32 THz.

Methods

The experiments were carried out on 3 corneas and 3 rabbit scleras, 2 whole rabbit eyes, and 3 human healthy adult scleras using a specially developed THz system based on reliable and easy‐to‐use continuous wave sources: a backward‐wave oscillator and an avalanche transit‐time diode.

Results

The transmittance spectra of the cornea and the sclera and the dependence of the reflection coefficient of these tissues in THz range on water percentage content were determined. Comparison of the rabbit cornea hydrated from 73.2% to 76.3% concentration by mass demonstrated an approximately linear relationship between THz reflectivity and water concentration. The decrease of free water concentration by 1% leads to a drop of the reflectance coefficient by 13%. The parameters studied displayed noticeable differences between the sclera and the cornea of rabbits and between rabbit sclera and human sclera.

Conclusions

Preliminary results demonstrate that the proposed technique, based on continuous THz radiation, may be used to create a device for noninvasive testing of corneal and scleral hydration, which has good potential of wide‐scale practical application.

The work was supported by the Russian Foundation of Basic Research (grant No.15‐29‐03843)
 
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  Series Volume Series Issue Edition  
  ISSN 1755375X ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1333  
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Author Kahl, O.; Ferrari, S.; Kovalyuk, V.; Vetter, A.; Lewes-Malandrakis, G.; Nebel, C.; Korneev, A.; Goltsman, G.; Pernice, W. url  openurl
  Title Spectrally resolved single-photon imaging with hybrid superconducting – nanophotonic circuits Type Miscellaneous
  Year (down) 2016 Publication arXiv Abbreviated Journal arXiv  
  Volume Issue Pages 1-20  
  Keywords waiveguide SSPD, SNSPD, imaging  
  Abstract The detection of individual photons is an inherently binary mechanism, revealing either their absence or presence while concealing their spectral information. For multi-color imaging techniques, such as single photon spectroscopy, fluorescence resonance energy transfer microscopy and fluorescence correlation spectroscopy, wavelength discrimination is essential and mandates spectral separation prior to detection. Here, we adopt an approach borrowed from quantum photonic integration to realize a compact and scalable waveguide-integrated single-photon spectrometer capable of parallel detection on multiple wavelength channels, with temporal resolution below 50 ps and dark count rates below 10 Hz. We demonstrate multi-detector devices for telecommunication and visible wavelengths and showcase their performance by imaging silicon vacancy color centers in diamond nanoclusters. The fully integrated hybrid superconducting-nanophotonic circuits enable simultaneous spectroscopy and lifetime mapping for correlative imaging and provide the ingredients for quantum wavelength division multiplexing on a chip.  
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  Notes Approved no  
  Call Number Serial 1334  
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Author Iomdina, E. N.; Goltsman, G. N.; Seliverstov, S. V.; Sianosyan, A. A.; Teplyakova, K. O.; Rusova, A. A. url  doi
openurl 
  Title Study of transmittance and reflectance spectra of the cornea and the sclera in the THz frequency range Type Journal Article
  Year (down) 2016 Publication J. Biomed. Opt. Abbreviated Journal J. Biomed. Opt.  
  Volume 21 Issue 9 Pages 97002 (1 to 5)  
  Keywords BWO, IMPATT diode, Schottky diode, medicine, animals, cornea, physiology, humans, rabbits, sclera diagnostic imaging, physiology  
  Abstract An adequate water balance (hydration extent) is one of the basic factors of normal eye function, including its external shells: the cornea and the sclera. Adequate control of corneal and scleral hydration is very important for early diagnosis of a variety of eye diseases, stating indications for and contraindications against keratorefractive surgeries and the choice of contact lens correction solutions. THz systems of creating images in reflected beams are likely to become ideal instruments of noninvasive control of corneal and scleral hydration degrees. This paper reports on the results of a study involving transmittance and reflectance spectra for the cornea and the sclera of rabbit and human eyes, as well as those of the rabbit eye, in the frequency range of 0.13 to 0.32 THz. The dependence of the reflectance coefficient of these tissues on water mass percentage content was determined. The experiments were performed on three corneas, three rabbit scleras, two rabbit eyes, and three human scleras. The preliminary results demonstrate that the proposed technique, based on the use of a continuous THz radiation, may be utilized to create a device for noninvasive control of corneal and scleral hydration, which has clear potential of broad practical application.  
  Address Moscow State Pedagogical University, Department of Physics, 29 Malaya Pirogovskaya Street, Moscow 119435, Russia  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1083-3668 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:27626901 Approved no  
  Call Number Serial 1335  
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Author Gayduchenko, I. A.; Fedorov, G. E.; Stepanova, T. S.; Titova, N.; Voronov, B. M.; But, D.; Coquillat, D.; Diakonova, N.; Knap, W.; Goltsman, G. N. url  doi
openurl 
  Title Asymmetric devices based on carbon nanotubes as detectors of sub-THz radiation Type Conference Article
  Year (down) 2016 Publication J. Phys.: Conf. Ser. Abbreviated Journal J. Phys.: Conf. Ser.  
  Volume 741 Issue Pages 012143 (1 to 6)  
  Keywords carbon nanotubes, CNT  
  Abstract Demand for efficient terahertz (THz) radiation detectors resulted in intensive study of the asymmetric carbon nanostructures as a possible solution for that problem. In this work, we systematically investigate the response of asymmetric carbon nanodevices to sub-terahertz radiation using different sensing elements: from dense carbon nanotube (CNT) network to individual CNT. We conclude that the detectors based on individual CNTs both semiconducting and quasi-metallic demonstrate much stronger response in sub-THz region than detectors based on disordered CNT networks at room temperature. We also demonstrate the possibility of using asymmetric detectors based on CNT for imaging in the THz range at room temperature. Further optimization of the device configuration may result in appearance of novel terahertz radiation detectors.  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1742-6588 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1336  
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Author Seliverstov, S. V.; Rusova, A. A.; Kaurova, N. S.; Voronov, B. M.; Goltsman, G. N. url  doi
openurl 
  Title Attojoule energy resolution of direct detector based on hot electron bolometer Type Conference Article
  Year (down) 2016 Publication J. Phys.: Conf. Ser. Abbreviated Journal J. Phys.: Conf. Ser.  
  Volume 741 Issue Pages 012165 (1 to 5)  
  Keywords NbN HEB detector  
  Abstract We characterize superconducting antenna-coupled NbN hot-electron bolometer (HEB) for direct detection of THz radiation operating at a temperature of 9.0 K. At signal frequency of 2.5 THz, the measured value of the optical noise equivalent power is 2.0×10-13 W-Hz-0.5. The estimated value of the energy resolution is about 1.5 aJ. This value was confirmed in the experiment with pulsed 1.55-μm laser employed as a radiation source. The directly measured detector energy resolution is 2 aJ. The obtained risetime of pulses from the detector is 130 ps. This value was determined by the properties of the RF line. These characteristics make our detector a device-of-choice for a number of practical applications associated with detection of short THz pulses.  
  Address  
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  Publisher IOP Publishing Place of Publication Editor  
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  Series Editor Series Title Abbreviated Series Title  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Seliverstov_2016 Serial 1337  
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Author Arutyunov, K. Y.; Ramos-Álvarez, A.; Semenov, A. V.; Korneeva, Y. P.; An, P. P.; Korneev, A. A.; Murphy, A.; Bezryadin, A.; Gol’tsman, G. N. url  openurl
  Title Quasi-1-dimensional superconductivity in highly disordered NbN nanowires Type Miscellaneous
  Year (down) 2016 Publication arXiv Abbreviated Journal  
  Volume Issue Pages  
  Keywords narrow NbN nanowires, BCS  
  Abstract The topic of superconductivity in strongly disordered materials has attracted a significant attention. In particular vivid debates are related to the subject of intrinsic spatial inhomogeneity responsible for non-BCS relation between the superconducting gap and the pairing potential. Here we report experimental study of electron transport properties of narrow NbN nanowires with effective cross sections of the order of the debated inhomogeneity scales. We find that conventional models based on phase slip concept provide reasonable fits for the shape of the R(T) transition curve. Temperature dependence of the critical current follows the text-book Ginzburg-Landau prediction for quasi-one-dimensional superconducting channel Ic~(1-T/Tc)^3/2. Hence, one may conclude that the intrinsic electronic inhomogeneity either does not exist in our structures, or, if exist, does not affect their resistive state properties.  
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  Notes Duplicated as 1332 Approved no  
  Call Number Serial 1338  
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Author Korneeva, Y.; Sidorova, M.; Semenov, A.; Krasnosvobodtsev, S.; Mitsen, K.; Korneev, A.; Chulkova, G.; Goltsman, G. url  doi
openurl 
  Title Comparison of hot-spot formation in NbC and NbN single-photon detectors Type Journal Article
  Year (down) 2016 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 26 Issue 3 Pages 1-4  
  Keywords NbC, NbN SSPD, SNSPD  
  Abstract We report an experimental investigation of the hot-spot evolution in superconducting single-photon detectors made of disordered superconducting materials with different diffusivity and energy downconversion time values, i.e., 33-nm-thick NbN and 23-nm-thick NbC films. We have demonstrated that, in NbC film, only 405-nm photons produce sufficiently large hot spot to trigger a single-photon response. The dependence of detection efficiency on bias current for 405-nm photons in NbC is similar to that for 3400-nm photons in NbN. In NbC, large diffusivity and downconversion time result in 1-D critical current suppression profile compared with the usual 2-D profile in NbN.  
  Address  
  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1348  
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Author Fedorov, G. E.; Stepanova, T. S.; Gazaliev, A. S.; Gaiduchenko, I. A.; Kaurova, N. S.; Voronov, B. M.; Goltzman, G. N. url  doi
openurl 
  Title Asymmetric devices based on carbon nanotubes for terahertz-range radiation detection Type Journal Article
  Year (down) 2016 Publication Semicond. Abbreviated Journal Semicond.  
  Volume 50 Issue 12 Pages 1600-1603  
  Keywords carbon nanotubes, CNT detectors  
  Abstract Various asymmetric detecting devices based on carbon nanotubes (CNTs) are studied. The asymmetry is understood as inhomogeneous properties along the conducting channel. In the first type of devices, an inhomogeneous morphology of the CNT grid is used. In the second type of devices, metals with highly varying work functions are used as the contact material. The relation between the sensitivity and detector configuration is analyzed. Based on the data obtained, approaches to the development of an efficient detector of terahertz radiation, based on carbon nanotubes are proposed.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1063-7826 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1776  
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Author Ryzhii, V.; Otsuji, T.; Ryzhii, M.; Leiman, V. G.; Fedorov, G.; Goltzman, G. N.; Gayduchenko, I. A.; Titova, N.; Coquillat, D.; But, D.; Knap, W.; Mitin, V.; Shur, M. S. url  doi
openurl 
  Title Two-dimensional plasmons in lateral carbon nanotube network structures and their effect on the terahertz radiation detection Type Journal Article
  Year (down) 2016 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.  
  Volume 120 Issue 4 Pages 044501 (1 to 13)  
  Keywords carbon nanotubes, CNT detectors, plasmons  
  Abstract We consider the carrier transport and plasmonic phenomena in the lateral carbon nanotube (CNT) networks forming the device channel with asymmetric electrodes. One electrode is the Ohmic contact to the CNT network and the other contact is the Schottky contact. These structures can serve as detectors of the terahertz (THz) radiation. We develop the device model for collective response of the lateral CNT networks which comprise a mixture of randomly oriented semiconductor CNTs (s-CNTs) and quasi-metal CNTs (m-CNTs). The proposed model includes the concept of the collective two-dimensional (2D) plasmons in relatively dense networks of randomly oriented CNTs (CNT “felt”) and predicts the detector responsivity spectral characteristics exhibiting sharp resonant peaks at the signal frequencies corresponding to the 2D plasmonic resonances. The detection mechanism is the rectification of the ac current due the nonlinearity of the Schottky contact current-voltage characteristics under the conditions of a strong enhancement of the potential drop at this contact associated with the plasmon excitation. The detector responsivity depends on the fractions of the s- and m-CNTs. The burning of the near-contact regions of the m-CNTs or destruction of these CNTs leads to a marked increase in the responsivity in agreement with our experimental data. The resonant THz detectors with sufficiently dense lateral CNT networks can compete and surpass other THz detectors using plasmonic effects at room temperatures.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1777  
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Author Schroeder, E.; Mauskopf, P.; Pilyavsky, G.; Sinclair, A.; Smith, N.; Bryan, S.; Mani, H.; Morozov, D.; Berggren, K.; Zhu, D.; Smirnov, K.; Vakhtomin, Y. url  doi
openurl 
  Title On the measurement of intensity correlations from laboratory and astronomical sources with SPADs and SNSPDs Type Conference Article
  Year (down) 2016 Publication Proc. SPIE Abbreviated Journal Proc. SPIE  
  Volume 9907 Issue Pages 99070P (1 to 13)  
  Keywords SPAD, NbN SSPD applications, SNSPD  
  Abstract We describe the performance of detector modules containing silicon single photon avalanche photodiodes (SPADs) and superconducting nanowire single photon detectors (SNSPDs) to be used for intensity interferometry. The SPADs are mounted in fiber-coupled and free-space coupled packages. The SNSPDs are mounted in a small liquid helium cryostat coupled to single mode fiber optic cables which pass through a hermetic feed-through. The detectors are read out with microwave amplifiers and FPGA-based coincidence electronics. We present progress on measurements of intensity correlations from incoherent sources including gas-discharge lamps and stars with these detectors. From the measured laboratory performance of the correlation system, we estimate the sensitivity to intensity correlations from stars using commercial telescopes and larger existing research telescopes.  
  Address  
  Corporate Author Thesis  
  Publisher SPIE Place of Publication Editor Malbet, F.; Creech-Eakman, M.J.; Tuthill, P.G.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference Optical and Infrared Interferometry and Imaging V  
  Notes Approved no  
  Call Number Serial 1809  
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