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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. url  doi
openurl 
  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 (up) 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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  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  
Permanent link to this record
 

 
Author Meledin, D.; Tong, C.-Y. E.; Blundell, R.; Goltsman, G. url  doi
openurl 
  Title Measurement of intermediate frequency bandwidth of hot electron bolometer mixers at terahertz frequency range Type Journal Article
  Year 2003 Publication IEEE Microw. Wireless Compon. Lett. Abbreviated Journal IEEE Microw. Wireless Compon. Lett.  
  Volume 13 Issue 11 Pages 493-495  
  Keywords waveguide NbN HEB mixers  
  Abstract (up) We have developed a new experimental setup for measuring the IF bandwidth of superconducting hot electron bolometer mixers. In our measurement system we use a chopped hot filament as a broadband signal source, and can perform a high-speed IF scan with no loss of accuracy when compared to coherent methods. Using this technique we have measured the 3 dB IF bandwidth of hot electron bolometer mixers, designed for THz frequency operation, and made from 3-4 nm thick NbN film deposited on an MgO buffer layer over crystalline quartz.  
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  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1531-1309 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1509  
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Author Meledin, D.; Tong, C. Y.-E.; Blundell, R.; Kaurova, N.; Smirnov, K.; Voronov, B.; Gol'tsman, G. url  openurl
  Title The sensitivity and IF bandwidth of waveguide NbN hot electron bolometer mixers on MgO buffer layers over crystalline quartz Type Conference Article
  Year 2002 Publication Proc. 13th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 13th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 65-72  
  Keywords waveguide NbN HEB mixers  
  Abstract (up) We have developed and characterized waveguide phonon-cooled NbN Hot Electron Bolometer (FMB) mixers fabricated from a 3-4 nm thick NbN film deposited on a 200nm thick MgO buffer layer over crystalline quartz. Double side band receiver noise temperatures of 900-1050 K at 1.035 THz, and 1300-1400 K at 1.26 THz have been measured at an intermediate frequency of 1.5 GHz. The intermediate frequency bandwidth, measured at 0.8 THz LO frequency, is 3.2 GHz at the optimal bias point for low noise receiver operation.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge, MA, USA Editor Harvard university  
  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 326  
Permanent link to this record
 

 
Author Tong, C. Edward; Trifonov, Andrey; Blundell, Raymond; Shurakov, Alexander; Gol’tsman, Gregory url  openurl
  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 (up) 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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  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1366  
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Author Ryabchun, S.; Tong, C.-Y. E.; Blundell, R.; Kimberk, R.; Gol'tsman, G. url  doi
openurl 
  Title Study of the effect of microwave radiation on the operation of HEB mixers in the terahertz frequency range Type Journal Article
  Year 2007 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 17 Issue 2 Pages 391-394  
  Keywords NbN HEB mixers  
  Abstract (up) We have investigated the effect of injecting microwave radiation, with a frequency much lower than that corresponding to the energy gap of the superconductor, on the performance of the hot-electron bolometer mixer incorporated into a THz heterodyne receiver. More specifically, we show that exposing the mixer to microwave radiation does not cause a significant rise of the receiver noise temperature and fall of the mixer conversion gain so long as the microwave power is a small fraction of local oscillator power. The injection of a small, but controlled amount of microwave power therefore enables active compensation of local oscillator power and coupling fluctuations which can significantly degrade the gain stability of hot electron bolometer mixer receivers.  
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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 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1427  
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