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Author Goltsman, G. N.; Shcherbatenko, M. L.; Lobanov, Y. V.; Kovalyuk, V. V.; Kahl, O.; Ferrari, S.; Korneev, A.; Pernice, W. H. P.
Title Superconducting nanowire single photon detector for coherent detection of weak optical signals Type (up) Abstract
Year 2016 Publication LPHYS'16 Abbreviated Journal LPHYS'16
Volume Issue Pages 1-2
Keywords SSPD, SNSPD
Abstract Traditionally, photon detectors are operated in a direct detection mode counting incident photonswith a known quantum efficiency. This procedure allows one to detect weak sources of radiation but allthe information about its frequency is limited by the optical filtering/resonating structures used which arenot as precise as would be required for some practical applications. In this work we propose heterodynereceiver based on a photon counting mixer which would combine excellent sensitivity of a photon countingdetector and excellent spectral resolution given by the heterodyne technique. At present, Superconducting-Nanowire-Single-Photon-Detectors (SNSPDs) [1] are widely used in a variety of applications providing thebest possible combination of the sensitivity and speed. SNSPDs demonstrate lack of drawbacks like highdark count rate or autopulsing, which are common for traditional semiconductor-based photon detectors,such as avalanche photon diodes.In our study we have investigated SNSPD operated as a photon counting mixer. To fully understandits behavior in such a regime, we have utilized experimental setup based on a couple of distributedfeedback lasers irradiating at 1.5 micrometers, one of which is being the Local Oscillator (LO) and theother mimics the test signal [2]. The SNSPD was operated in the current mode and the bias currentwas slightly below of the critical current. Advantageously, we have found that LO power needed for anoptimal mixing is of the order of hundreds of femtowatts to a few picowatts, which is promising for manypractical applications, such as receiver matrices [3]. With use of the two lasers, one can observe thevoltage pulses produced by the detected photons, and the time distribution of the pulses reproduces thefrequency difference between the lasers, forming power response at the intermediate frequency which canbe captured by either an oscilloscope (an analysis of the pulse statistics is needed) or by an RF spectrumanalyzer. Photon-counting nature of the detector ensures quantum-limited sensitivity with respect to theoptical coupling achieved. In addition to the chip SNSPD with normal incidence coupling, we use thedetectors with a travelling wave geometry design [4]. In this case a NbN nanowire is placed on the topof a Si3N4 nanophotonic waveguide, thus increasing the efficient interaction length. For this reason it ispossible to achieve almost complete absorption of photons and reduce the detector footprint. This reducesthe noise of the device together with the expansion of the bandwidth. Integrated device scheme allowsus to measure the optical losses with high accuracy. Our approach is fully scalable and, along with alarge number of devices integrated on a single chip can be adapted to the mid and far IR ranges wherephoton-counting measurement may be beneficial as well [5].Acknowledgements: This work was supported in part by the Ministry of Education and Science of theRussian Federation, contract No. 14.B25.31.0007 and by RFBR grant No. 16-32-00465.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1220
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Author Iomdina, E. N.; Seliverstov, S.; Sianosyan, A.; Teplyakova, K.; Rusova, A.; Goltsman, G.
Title The prospects of using the radiation for the assessment of corneal and scleral hydration Type (up) Abstract
Year 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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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1755375X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1333
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Author Столяров, А. В.
Title Программирование. Введение в профессию. Том 1. Азы программирования Type (up) Book Whole
Year 2016 Publication МАКС Пресс Abbreviated Journal
Volume Issue Pages
Keywords programming, computer science
Abstract Первый том серии «Программирование: введение в профессию» включает две основные части. В первую часть книги вошли избранные сведения из истории вычислительной техники, обсуждение некоторых областей математики, непосредственно используемых программистами (таких как алгебра логики, комбинаторика, позиционные системы счисления), математических основ программирования (теория вычислимости и теория алгоритмов), принципы построения и функционирования вычислительных систем, начальные сведения о работе с командной строкой ОС Unix. Вторая часть посвящена начальным навыкам составления компьютерных программ на примере Free Pascal под ОС Unix. Материал ориентирован на изучение в будущем языка Си, так что, в частности, много внимания уделено работе с адресами и указателями, построению списков и других динамических структур данных; в то же время многие возможности Паскаля из рассмотрения исключены. Даются сведения о правилах оформления текстов программ, о тестировании и отладке.
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Corporate Author Thesis
Publisher Place of Publication Москва Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-5-317-05222-5 Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1133
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Author Столяров, А. В.
Title Программирование. Введение в профессию. Том 2. Низкоуровневое программирование Type (up) Book Whole
Year 2016 Publication МАКС Пресс Abbreviated Journal
Volume Issue Pages
Keywords programming, computer science
Abstract Во второй том книги «Программирование: введение в профессию» вошли её третья и четвёртая части. Третья часть книги посвящена программированию на уровне машинных команд на примере ассемблера NASM. Рассматривается «юзерспейсовская» часть системы команд i386, конвенции системных вызовов Linux/i386 и FreeBSD/i386, изучается макропроцессор, раздельная трансляция и работа компоновщика, приведены сведения об арифметике с плавающей точкой. Четвёртая часть, посвящённая языку Си, включает, кроме собственно описания этого языка, также краткие сведения о библиотеке ncurses; рассказ о том, как использовать компилятор Си без его стандартной библиотеки; дополнительные сведения об инструментах сборки и отладки программ; наконец, в книге приводится краткое описание систем контроля версий CVS и git.
Address
Corporate Author Thesis
Publisher Place of Publication Москва Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-5-317-05301-7 Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1134
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Author Voss, Chris; Raz, Tahl
Title Never split the difference: negotiating as if your life depended on it Type (up) Book Whole
Year 2016 Publication Abbreviated Journal
Volume Issue Pages
Keywords business, negotiating, psychology, FBI
Abstract
Address
Corporate Author Thesis
Publisher HarperCollins Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 978-0-06-240780-1 Medium
Area Expedition Conference
Notes pdf, epub, mp3 (audio book) -- 85 MB in total Approved no
Call Number Serial 1838
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