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Author Казаков, А. Ю.; Селиверстов, С. В.; Дивочий, А. В.; Смирнов, К. В.; Финкель, М. И.; Вахтомин, Ю. Б.
Title Возможность применения сверхпроводниковых материалов в качестве отражающего покрытия зеркала телескопа, предназначенного для наблюдений анизотропии реликтового излучения Type Journal Article
Year 2012 Publication Преподаватель ХХI век Abbreviated Journal
Volume Issue 3 Pages 221-224
Keywords (down) submillimeter radio telescope
Abstract В статье исследуется возможность использования сверхпроводящего материала в качестве отражающего слоя зеркала субмиллиметрового телескопа, охлажденного до криогенных температур и предназначенного для наблюдений реликтового излучения. Для нескольких сверхпроводниковых материалов вычислен диапазон частот, в котором флуктуации теплового излучения покрытия меньше флуктуаций источника. Показана перспективность применения покрытия из Nb3Ge.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Russian 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 1820
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Author Семенов, А. В.; Корнеев, А. А.; Лобанов, Ю. В.; Корнеева, Ю. П.; Рябчун, С. А.; Лаврова, О. С.; Третьяков, И. В.; Флоря, И. Н.; Силаев, М. А.; Кинев, Н. В.; Ковалюк, В. В.; Смирнов, К. В.; Гольцман, Г. Н.
Title Поляризация электромагнитной волны вблизи фокуса зеркала и системы зеркал в субтерагерцовом диапазоне частот Type Journal Article
Year 2012 Publication Современные проблемы науки и образования Abbreviated Journal
Volume Issue 2 Pages
Keywords (down) sub-terahertz radio telescope
Abstract Рассмотрено влияние оптической системы телескопа на поляризацию принимаемого электромагнитного сигнала. Описано изменение поляризации луча при отражении от произвольно ориентированной поверхности зеркала. Учтены искажения поляризации, обусловленные как отклонением лучей от первоначального направления, так и различием в коэффициентах отражения для разных поляризаций в случае неидеального отражения. В рамках метода Френеля получены оценочные формулы, дающие отношение амплитуд поля с исходной поляризацией и с поляризацией, перпендикулярной исходной, вблизи фокальной точки оптической системы. Формулы выведены для нескольких практически важных случаев, в том числе для параболического зеркала и системы двух зеркал. Оценена верхняя граница поляризационных искажений в пределах кружка Эйри. Полученные оценки согласуются с результатами численного расчёта для двухзеркального радиотелескопа субтерагерцового диапазона.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Russian Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes 9 страниц; УДК 535-47 Approved no
Call Number Serial 1819
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Author Shcherbatenko, M.; Elezov, M.; Sych, D.; Goltsman, G. N.
Title Optimal fiber optic scheme for sub-SQL quantum receiver realization Type Conference Article
Year 2020 Publication J. Phys.: Conf. Ser. Abbreviated Journal J. Phys.: Conf. Ser.
Volume 1695 Issue Pages 012140
Keywords (down) sub-SQL, below quantum limit, QL, system quantum limit, SQL
Abstract Practical implementation of high-precision quantum measurements is an important problem in modern science. One of the main parts of the quantum receiver is the optical scheme. We developed and tested several optical circuits based on different types of interferometers, namely Sagnac-based scheme, Mach-Zehnder-based scheme, and Michelson-based scheme. All these schemes are assembled with optical fibers and fiber-optic components, since the fiber-optic implementation is closest to application in practical devices. Schemes were evaluated according to two main criteria: extinction and interference stability. On the basis of the obtained data, it can be concluded that the most suitable is the scheme based on the Mach-Zehnder interferometer. In continuous mode, we were able to obtain an interference extinction about 30 dB with acceptable temporal stability.
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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 1742-6588 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1265
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Author Sych, Denis; Shcherbatenko, Michael; Elezov, Michael; Goltsman, Gregory N.
Title Towards the improvement of the heterodyne receiver sensitivity beyond the quantum noise limit Type Conference Article
Year 2018 Publication Proc. 29th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 29th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 245-247
Keywords (down) standard quantum limit, sub-SQL quantum receiver, Kennedy receiver, SSPD, SNSPD
Abstract Noise reduction in heterodyne receivers of the terahertz range is an important issue for astronomical applications. Quantum fluctuations, also known as shot noise, prohibit errorless measurements of the amplitude of electro-magnetic waves, and introduce the so-called standard quantum limit (SQL) on the minimum error of the heterodyne measurements. Nowadays, the sensitivity of modern heterodyne receivers approaches the SQL, and the growing demand for the improvement of measurement precision stimulates a number of both theoretical and experimental efforts to design novel measurement techniques aimed at overcoming the SQL. Here we demonstrate the first steps towards the practical implementation of a sub-SQL quantum receiver. As the principal resources, it requires a highly efficient single-photon counting detector and an interferometer-based scheme for mixing the signal with a low-power local oscillator. We describe the idea of such receiver and its main components.
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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 1314
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Author Vetter, A.; Ferrari, S.; Rath, P.; Alaee, R.; Kahl, O.; Kovalyuk, V.; Diewald, S.; Goltsman, G. N.; Korneev, A.; Rockstuhl, C.; Pernice, W. H. P.
Title Cavity-enhanced and ultrafast superconducting single-photon detectors Type Journal Article
Year 2016 Publication Nano Lett. Abbreviated Journal Nano Lett.
Volume 16 Issue 11 Pages 7085-7092
Keywords (down) SSPD; SNSPD; multiphoton detection; nanophotonic circuit; photonic crystal cavity
Abstract Ultrafast single-photon detectors with high efficiency are of utmost importance for many applications in the context of integrated quantum photonic circuits. Detectors based on superconductor nanowires attached to optical waveguides are particularly appealing for this purpose. However, their speed is limited because the required high absorption efficiency necessitates long nanowires deposited on top of the waveguide. This enhances the kinetic inductance and makes the detectors slow. Here, we solve this problem by aligning the nanowire, contrary to usual choice, perpendicular to the waveguide to realize devices with a length below 1 mum. By integrating the nanowire into a photonic crystal cavity, we recover high absorption efficiency, thus enhancing the detection efficiency by more than an order of magnitude. Our cavity enhanced superconducting nanowire detectors are fully embedded in silicon nanophotonic circuits and efficiently detect single photons at telecom wavelengths. The detectors possess subnanosecond decay ( approximately 120 ps) and recovery times ( approximately 510 ps) and thus show potential for GHz count rates at low timing jitter ( approximately 32 ps). The small absorption volume allows efficient threshold multiphoton detection.
Address Institute of Physics, University of Munster , 48149 Munster, Germany
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984 ISBN Medium
Area Expedition Conference
Notes PMID:27759401 Approved no
Call Number Serial 1208
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