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Author | Trifonov, A.; Tong, C.-Y. E.; Blundell, R.; Ryabchun, S.; Gol'tsman, G. | ||||
Title | Probing the stability of HEB mixers with microwave injection | Type | Journal Article | ||
Year | 2015 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
Volume | 25 | Issue | 3 | Pages | 2300404 (1 to 4) |
Keywords | NbN HEB mixer, stability, Allan-variance | ||||
Abstract | Using a microwave probe as a tool, we have performed experiments aimed at understanding the origin of the output-power fluctuations in hot-electron-bolometer (HEB) mixers. We use a probe frequency of 1.5 GHz. The microwave probe picks up impedance changes of the HEB, which are examined upon demodulation of the reflected wave outside the cryostat. This study shows that the HEB mixer operates in two different regimes under a terahertz pump. At a low pumping level, strong pulse modulation is observed, as the device switches between the superconducting state and the normal state at a rate of a few megahertz. When pumped much harder, to approximate the low-noise mixer operating point, residual modulation can still be observed, showing that the HEB mixer is intrinsically unstable even in the resistive state. Based on these observations, we introduced a low-frequency termination to the HEB mixer. By terminating the device in a 50-Ω resistor in the megahertz frequency range, we have been able to improve the output-power Allan time of our HEB receiver by a factor of four to about 10 s for a detection bandwidth of 15 MHz, with a corresponding gain fluctuation of about 0.035%. | ||||
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Language | Summary Language | Original Title | |||
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Series Volume | Series Issue | Edition | |||
ISSN | 1051-8223 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 1355 | |||
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Author | Lobanov, Y.; Shcherbatenko, M.; Finkel, M.; Maslennikov, S.; Semenov, A.; Voronov, B. M.; Rodin, A. V.; Klapwijk, T. M.; Gol'tsman, G. N. | ||||
Title | NbN hot-electron-bolometer mixer for operation in the near-IR frequency range | Type | Journal Article | ||
Year | 2015 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
Volume | 25 | Issue | 3 | Pages | 2300704 (1 to 4) |
Keywords | HEB mixer, IR, optical antenna | ||||
Abstract | Traditionally, hot-electron-bolometer (HEB) mixers are employed for THz and “super-THz” heterodyne detection. To explore the near-IR spectral range, we propose a fiber-coupled NbN film based HEB mixer. To enhance the incident-light absorption, a quasi-antenna consisting of a set of parallel stripes of gold is used. To study the antenna effect on the mixer performance, we have experimentally studied a set of devices with different size of the Au stripe and spacing between the neighboring stripes. With use of the well-known isotherm technique we have estimated the absorption efficiency of the mixer, and the maximum efficiency has been observed for devices with the smallest pitch of the alternating NbN and NbN-Au stripes. Also, a proper alignment of the incident Eâƒ<2014>-field with respect to the stripes allows us to improve the coupling further. Studying IV-characteristics of the mixer under differently-aligned Eâƒ<2014>-field of the incident radiation, we have noticed a difference in their shape. This observation suggests that a difference exists in the way the two waves with orthogonal polarizations parallel and perpendicular Eâƒ<2014>-field to the stripes heat the electrons in the HEB mixer. The latter results in a variation in the electron temperature distribution over the HEB device irradiated by the two waves. | ||||
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Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 952 | |||
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Author | Korneev, A. A.; Korneeva, Y. P.; Mikhailov, M. Yu.; Pershin, Y. P.; Semenov, A. V.; Vodolazov, D. Yu.; Divochiy, A. V.; Vakhtomin, Y. B.; Smirnov, K. V.; Sivakov, A. G.; Devizenko, A. Yu.; Goltsman, G. N. | ||||
Title | Characterization of MoSi superconducting single-photon detectors in the magnetic field | Type | Journal Article | ||
Year | 2015 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
Volume | 25 | Issue | 3 | Pages | 2200504 (1 to 4) |
Keywords | SSPD, SNSPD | ||||
Abstract | We investigate the response mechanism of nanowire superconducting single-photon detectors (SSPDs) made of amorphous MoxSi1-x. We study the dependence of photon count and dark count rates on bias current in magnetic fields up to 113 mT at 1.7 K temperature. The observed behavior of photon counts is similar to the one recently observed in NbN SSPDs. Our results show that the detecting mechanism of relatively high-energy photons does not involve the vortex penetration from the edges of the film, and on the contrary, the detecting mechanism of low-energy photons probably involves the vortex penetration from the film edges. | ||||
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Language | Summary Language | Original Title | |||
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Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | RPLAB @ akorneev @ KorneevIEEE2015 | Serial | 991 | ||
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Author | Tong, C.-Y. E.; Trifonov, A.; Shurakov, A.; Blundell, R.; Gol’tsman, G. | ||||
Title | A microwave-operated hot-electron-bolometric power detector for terahertz radiation | Type | Journal Article | ||
Year | 2015 | Publication | IEEE Trans. Appl. Supercond. | Abbreviated Journal | IEEE Trans. Appl. Supercond. |
Volume | 25 | Issue | 3 | Pages | 2300604 (1 to 4) |
Keywords | NbN HEB mixer | ||||
Abstract | A new class of microwave-operated THz power detectors based on the NbN hot-electron-bolometer (HEB) mixer is proposed. The injected microwave signal ( 1 GHz) serves the dual purpose of pumping the HEB element and enabling the read-out of the internal state of the device. A cryogenic amplifier amplifies the reflected microwave signal from the device and a homodyne scheme recovers the effects of the incident THz radiation. Two modes of operation have been identified, depending on the level of incident radiation. For weak signals, we use a chopper to chop the incident radiation against a black body reference and a lock-in amplifier to perform synchronous detection of the homodyne readout. The voltage measured is proportional to the incident power, and we estimate an optical noise equivalent power of 5pW/ √Hz at 0.83 THz. At higher signal levels, the homodyne circuit recovers the stream of steady relaxation oscillation pulses from the HEB device. The frequency of these pulses is in the MHz frequency range and bears a linear relationship with the incident THz radiation over an input power range of 15 dB. A digital frequency counter is used to measure THz power. The applicable power range is between 1 nW and 1 μW. | ||||
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Language | Summary Language | Original Title | |||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1558-2515 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 1354 | |||
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Author | Mehdi, I.; Gol'tsman, G.; Putz, P. | ||||
Title | Introduction to the mini-special-issue on the 25th international symposium on space terahertz technology (ISSTT) | Type | Miscellaneous | ||
Year | 2015 | Publication | IEEE Trans. THz Sci. Technol. | Abbreviated Journal | IEEE Trans. THz Sci. Technol. |
Volume | 5 | Issue | 1 | Pages | 14-15 |
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Abstract | THE 25th International Symposium on Space Terahertz Technology (ISSTT) was held in Moscow, Russia, between April 27–30, 2014. The conference was organized by Moscow State Pedagogical University and the Higher School of Economics (National Research University) and Chaired by Professor Gregory Gol'tsman of Moscow State Pedagogical University. The conference was attended by roughly 150 participants from 15 countries. The technology covered by ISSTT includes detectors, devices, circuits and systems in various areas of THz science and technology. Each year this symposium brings together the global THz space science technology community, and as such, emphasizes the broad international collaboration that is required to execute these large complicated instrument programs that dominate this field. However, talks covering technologies for balloon, aircraft, and ground-based telescopes were also presented. In this special section of IEEE Transactions on Terahertz Science and Technology, we include eight expanded papers from the 25th ISSTT symposium. The papers range from development of SIS mixers to optical adjustment systems for radio telescopes. The 26th ISSTT will be held in Boston, MA, USA, during March 16–18, 2015. Researchers and scientist involved in THz research are invited to attend this symposium (more details are at http://www.cfa.harvard.edu/events/2015/isstt2015/). You can access the full list of papers presented at the ISSTT symposia from the National Radio Astronomy Observatory website: http://www.nrao.edu/meetings/isstt/index.shtml Yours sincerely |
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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 | 2156-342X | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Approved | no | |||
Call Number | Serial | 1353 | |||
Permanent link to this record |