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Author Gol'tsman, G.; Kouminov, P.; Goghidze, I.; Gershenzon, E.
Title Nonequilibrium kinetic inductive response of YBCO thin films to low power laser pulses Type Journal Article
Year 1995 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 5 Issue 2 Pages 2591-2594
Keywords YBCO HTS KID
Abstract (down) We have discovered a transient nonequilibrium kinetic inductive voltage response of YBCO thin films to 20 ps pulses of YAG:Nd laser radiation with 0.63 /spl mu/m and 1.54 /spl mu/m wavelength. By increasing the sensitivity of the read-out system with 100 ps resolution time and diminishing the light intensity (fluence 0.1-2 /spl mu/J/cm/sup 2/) and transport current (density /spl les/10/sup 5/ A/cm/sup 2/) we were able to observe a peculiar bipolar signal form with nearly equal amplitudes for each sign. The integration of the kinetic inductive response over time gives the result which is qualitatively, of the same form as the response in the resistive and normal states: the nonequilibrium picosecond scale component is followed by the bolometric nanosecond component. The nonequilibrium response is interpreted as suppression of the order parameter by excess quasiparticles followed by a change both in resistance (for the resistive state) and in kinetic inductance (for the superconducting state).
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Publisher Place of Publication Editor
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 1621
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Author Yngvesson, K. S.; Gerecht, E.; Musante, C. F.; Zhuang, Y.; Ji, M.; Goyette, T. M.; Dickinson, J. C.; Waldman, J.; Yagoubov, P. A.; Gol’tsman, G. N.; Voronov, B. M.; Gershenzon, E. M.
Title Low-noise HEB heterodyne receivers and focal plane arrays for the THz regime using NbN Type Conference Article
Year 1999 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 3795 Issue Pages 357-368
Keywords NbN HEB mixers
Abstract (down) We have developed prototype HEB receivers using thin film superconducting NbN devices deposited on silicon substrates. The devices are quasi-optically coupled through a silicon lens and a self-complementary log-specific toothed antenna. We measured DSB receiver noise temperatures of 500 K (13 X hf/2k) at 1.56 THz and 1,100 K (20 X hf/2k) at 2.24 THz. Noise temperatures are expected to fall further as devices and quasi-optical coupling methods are being optimized. The measured 3 dB IF conversion gain bandwidth for one device was 3 GHz, and it is estimated that the bandwidth over which the receiver noise temperature is within 3 dB of its minimum value is 6.5 GHz which is sufficient for a number of practical applications. We will discuss our latest results and give a detailed description of our prototype setup and experiments. We will also discuss our plans for developing focal plane arrays with tens of Hot Electron Bolometric mixer elements on a single silicon substrate which will make real time imaging systems in the THz region feasible.
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Corporate Author Thesis
Publisher SPIE Place of Publication Editor Hwu, R.J.; Wu, K.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference Terahertz and Gigahertz Photonics
Notes Approved no
Call Number Serial 1561
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Author Kawamura, J.; Tong, C.-Y. E.; Blundell, R.; Papa, D. C.; Hunter, T. R.; Patt, F.; Gol’tsman, G.; Gershenzon, E.
Title Terahertz-frequency waveguide NbN hot-electron bolometer mixer Type Journal Article
Year 2001 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.
Volume 11 Issue 1 Pages 952-954
Keywords NbN HEB mixers
Abstract (down) We have developed a low-noise waveguide heterodyne receiver for operation near 1 THz using phonon-cooled NbN hot-electron bolometers. The mixer elements are submicron-sized microbridges of 4 nm-thick NbN film fabricated on a quartz substrate. Operating at a bath temperature of 4.2 K, the double-sideband receiver noise temperature is 760 K at 1.02 THz and 1100 K at 1.26 THz. The local oscillator is provided by solid-state sources, and power measured at the source is less than 1 /spl mu/W. The intermediate frequency bandwidth exceeds 2 GHz. The receiver was used to make the first ground-based heterodyne detection of a celestial spectroscopic line above 1 THz.
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Publisher Place of Publication Editor
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 1546
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Author Gerecht, E.; Musante, C. F.; Wang, Z.; Yngvesson, K. S.; Waldman, J.; Gol'tsman, G. N.; Yagoubov, P. A.; Svechnikov, S. I.; Voronov, B. M.; Cherednichenko, S. I.; Gershenzon, E. M.
Title NbN hot electron bolometric mixer for 2.5 THz: the phonon cooled version Type Conference Article
Year 1997 Publication Proc. 8th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 8th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 258-271
Keywords NbN HEB mixers
Abstract (down) We describe an investigation of a NbN HEB mixer for 2.5 THz. NbN HEBs are phonon-cooled de-. vices which are expected, according to theory, to achieve up to 10 GHz IF conversion gain bandwidth. We have developed an antenna coupled device using a log-periodic antenna and a silicon lens. We have demon- strated that sufficient LO power can be coupled to the device in order to bring it to the optimum mixer oper- ating point. The LO power required is less than 1 microwatts as measured directly at the device. We also describe the impedance characteristics of NbN devices and compare them with theory. The experimental results agree with theory except for the imaginary part of the impedance at very low frequencies as was demonstrated by other groups.
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Area Expedition Conference
Notes Approved no
Call Number Serial 1605
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Author Gerecht, E.; Musante, C. F.; Wang, Z.; Yngvesson, K. S.; Mueller, E. R.; Waldman, J.; Gol'tsman, G. N.; Voronov, B. M.; Cherednichenco, S. I.; Svechnikov, S. I.; Yagoubov, P. A.; Gershenzon, E. M.
Title Optimization of hot eleciron bolometer mixing efficiency in NbN at 119 micrometer wavelength Type Conference Article
Year 1996 Publication Proc. 7th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 7th Int. Symp. Space Terahertz Technol.
Volume Issue Pages 584-600
Keywords NbN HEB mixers
Abstract (down) We describe an investigation of a NbN HEB mixer for 2.5 THz. An intrinsic conversion loss of 23 dB has been measured with a two-laser measurement technique. The conversion loss was limited by the LO power available and is expected to decrease to 10 dB or less when sufficient LO power is available. For this initial experiment we used a prototype device which is directly coupled to the laser beams. We present results for a back-short technique that improves the optical coupling to the device and describe our progress for an antenna-coupled device with a smaller dimension. Based on our measured data for conversion loss and device output noise level, we predict that NbN HEB mixers will be capable of achieving DSB receiver noise temperatures of ten times the quantum noise limit in the THz range.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1616
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