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Author | Tong, C. Edward; Trifonov, Andrey; Blundell, Raymond; Shurakov, Alexander; Gol’tsman, Gregory | ||||
Title | A digital terahertz power meter based on an NbN thin film | Type | Abstract | ||
Year | 2014 | Publication | Proc. 25th Int. Symp. Space Terahertz Technol. | Abbreviated Journal | Proc. 25th Int. Symp. Space Terahertz Technol. |
Volume | Issue | Pages | 170 | ||
Keywords | waveguide NbN HEB mixers | ||||
Abstract | We have further studied the effect of subjecting a superconducting Hot Electron Bolometer (HEB) element made from an NbN thin film to microwave radiation. Since the photon energy is weak, the microwave radiation does not simply heat the film, but generates a bi-static state, switching between the superconducting and normal states, upon the application of a small voltage bias. Indeed, a relaxation oscillation of a few MHz has previously been reported in this regime [1]. Switching between the superconducting and normal states modulates the reflected microwave pump power from the device. A simple homodyne setup readily recovers the spontaneous switching waveform in the time domain. The switching frequency is a function of both the bias voltage (DC heating) and the applied microwave power. In this work, we use a 0.8 THz HEB waveguide mixer for the purpose of demonstration. The applied microwave pump, coupled through a directional coupler, is at 1 GHz. Since the pump power is of the order of a few μW, a room temperature amplifier is sufficient to amplify the reflected pump power from the HEB mixer, which beats with the microwave source in a homodyne set-up. After further amplification, the switching waveform is passed onto a frequency counter. The typical frequency of the switching pulses is 3-5 MHz. It is found that the digital frequency count increases with higher microwave pump power. When the HEB mixer is subjected to additional optical power at 0.8 THz, the frequency count also increases. When we vary the incident optical power by using a wire grid attenuator, a linear relationship is observed between the frequency count and the applied optical power, over at least an order of magnitude of power. This phenomenon can be exploited to develop a digital power meter, using a very simple electronics setup. Further experiments are under way to determine the range of linearity and the accuracy of calibration transfer from the microwave to the THz regime. References 1. Y. Zhuang, and S. Yngvesson, “Detection and interpretation of bistatic effects in NbN HEB devices,” Proc. 13 th Int. Symp. Space THz Tech., 2002, pp. 463–472. | ||||
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Call Number | Serial | 1366 | |||
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Author | Lusche, R.; Semenov, A.; Korneeva, Y.; Trifonov, A.; Korneev, A.; Gol'tsman, G.; Hübers, H.-W. | ||||
Title | Effect of magnetic field on the photon detection in thin superconducting meander structures | Type | Journal Article | ||
Year | 2014 | Publication | Phys. Rev. B | Abbreviated Journal | Phys. Rev. B |
Volume | 89 | Issue | 10 | Pages | 104513 (1 to 7) |
Keywords | NbN SSPD, SNSPD | ||||
Abstract | We have studied the influence of an externally applied magnetic field on the photon and dark count rates of meander-type niobium nitride superconducting nanowire single-photon detectors. Measurements have been performed at a temperature of 4.2 K, and magnetic fields up to 250 mT have been applied perpendicularly to the meander plane. While photon count rates are field independent at weak applied fields, they show a strong dependence at fields starting from approximately ±25 mT. This behavior, as well as the magnetic field dependence of the dark count rates, is in good agreement with the recent theoretical model of vortex-assisted photon detection and spontaneous vortex crossing in narrow superconducting lines. However, the local reduction of the superconducting free energy due to photon absorption, which is the fitting parameter in the model, increases much slower with the photon energy than the model predicts. Furthermore, changes in the free-energy during photon counts and dark counts depend differently on the current that flows through the meander. This indicates that photon counts and dark counts occur in different parts of the meander. | ||||
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ISSN | 1098-0121 | ISBN | Medium | ||
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Notes | Approved | no | |||
Call Number | Serial | 1367 | |||
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Author | Gol’tsman, G.N. | ||||
Title | Overview of recent results for superconducting NbN terahertz and optical detectors and mixers | Type | Miscellaneous | ||
Year | 2014 | Publication | SM2 – Seminar on Terahertz Photonics | Abbreviated Journal | |
Volume | Issue | Pages | 0562 | ||
Keywords | NbN SSPD, SNSPD, HEB | ||||
Abstract | We present our recent achievements in the development of sensitive and ultrafast thin-film superconducting sensors: hot-electron bolometers (HEB), HEB-mixers for terahertz range and infrared single-photon counters. These sensors have already demonstrated a performance that makes them devices-of-choice for many terahertz and optical applications. | ||||
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Call Number | Serial | 1746 | |||
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Author | Смирнов, Константин Владимирович; Чулкова, Галина Меркурьевна; Вахтомин, Юрий Борисович; Корнеев, Александр Александрович; Окунев, Олег Валерьевич; Дивочий, Александр Валерьевич; Семенов, Александр Владимирович; Гольцман, Григорий Наумович | ||||
Title | Особенности разогрева и релаксации горячих электронов О-754 в тонкопленочных cверхпроводниковых наноструктурах и 2D полупроводниковых гетероструктурах при поглощении излучения инфракрасного и терагерцового диапазонов | Type | Book Whole | ||
Year | 2014 | Publication | Abbreviated Journal | ||
Volume | Issue | Pages | |||
Keywords | 2DEG | ||||
Abstract | В монографии рассмотрены основные особенности эффекта электронного разогрева в тонких сверхпроводниковых пленках и полупроводниковых гетеропереходах, возникающего при поглощении носителями заряда излучений терагерцового и инфракрасного диапазонов. Значительная часть монографии посвящена представлению современных достижений при использовании указанного эффекта для создания приемных устройств с рекордными характеристиками: терагерцовых гетеродинных и болометрических приемников на основе сверхпроводниковых и полупроводниковых структур; сверхпроводниковых приемников одиночных ИК фотонов. В работе также подробно рассмотрены основы современной сверхпроводниковой тонкопленочной технологии. Монография может быть полезна студентам старших курсов, аспирантам и начинающим исследователям, работающим в области физики твердого тела, оптики, радиофизики. |
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Address | Москва | ||||
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Publisher | МПГУ | Place of Publication | Editor | ||
Language | Russian | Summary Language | Original Title | ||
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ISSN | ISBN | 978-5-4263-0145-0 | Medium | ||
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Notes | 240 страниц | Approved | no | ||
Call Number | Serial | 1814 | |||
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Author | Гольцман, Григорий Наумович; Корнеев, Александр Александрович; Антипов, Андрей Владимирович; Минаева, Ольга Вячеславовна; Дивочий, Александр Валерьевич; Антипов, Сергей Владимирович; Вахтомин, Юрий Борисович; Смирнов, Константин Владимирович | ||||
Title | Способ фильтрации фонового излучения инфракрасного диапазона | Type | Patent | ||
Year | 2014 | Publication | Abbreviated Journal | ||
Volume | Issue | RU 2510056 C1 | Pages | ||
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Abstract | Изобретение относится к способам уменьшения интенсивности фонового излучения инфракрасного диапазона. Способ фильтрации фонового излучения инфракрасного диапазона, падающего на сверхпроводниковый однофотонный детектор, включает передачу излучения инфракрасного диапазона с длиной волны 0,4-1,8 микрометров на сверхпроводниковый однофотонный детектор при помощи одномодового волокна, частично находящегося при температуре 4,0-4,4 К. При этом длина охлаждаемого участка одномодового волокна составляет 0,2-3,5 м. Технический результат заключается в повышении надежности работы фотонных детекторов. 2 з.п. ф-лы. | ||||
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Notes | Approved | no | |||
Call Number | Serial | 1815 | |||
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