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Author Ekström, H.; Karasik, B.; Kollberg, E.; Gol'tsman, G.; Gershenzon, E. url  openurl
  Title 350 GHz NbN hot electron bolometer mixer Type Conference Article
  Year 1995 Publication Proc. 6th Int. Symp. Space Terahertz Technol. Abbreviated Journal Proc. 6th Int. Symp. Space Terahertz Technol.  
  Volume Issue Pages 269-283  
  Keywords NbN HEB mixers  
  Abstract Superconducting NbN hot-electron bolometer (HEB) mixer devices have been fabricated and measured at 350 GHz. The HEB is integrated with a double dipole antenna on an extended crystalline quartz hyper hemispherical substrate lens. Heterodyne measurement gave a -3 dB bandwidth, mainly determined by the electron- phonon interaction time, of about 680 and 1000 MHz for two different films with Tc = 8.5 and 11 K respectively. The measured DSB receiver noise temperature is around 3000 K at 800 MHz IF frequency. The main contribution to the output noise from the device is due to electron temperature fluctuations with the equivalent output noise temperature TFL-100 K. TH, has the same frequency dependence as the IF response. The contribution from Johnson noise is of the order of T. The RF coupling loss is estimated to be = 6 dB. The film with lower Tc, had an estimated intrinsic low-frequency conversion loss = 7 dB, while the other film had a conversion loss as high as 14 dB. The difference in intrinsic conversion loss is explained by less uniform absorption of radiation. Measurements of the small signal impedance shows a transition of the output impedance from the DC differential resistance Rd=dV/dI in the low frequency limit to the DC resistance R 0 =Uoff 0 in the bias point for frequencies above 3 GHz. We judge that the optimum shape of the IV-characteristic is more easily obtained at THz frequencies where the main restriction in performance should come from problems with the RF coupling.  
  Address  
  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 (up) Serial 1628  
Permanent link to this record
 
 
Author Zorin, M.; Lindgren, M.; Danerud, M.; Karasik, B.; Winkler, D.; Gol'tsman, G.; Gershenzon, E. url  doi
openurl 
  Title Nonequilibrium and bolometric responses of YBaCuO thin films to high-frequency modulated laser radiation Type Journal Article
  Year 1995 Publication J. Supercond. Abbreviated Journal J. Supercond.  
  Volume 8 Issue 1 Pages 11-15  
  Keywords YBCO HTS HEB  
  Abstract Picosecond nonequilibrium and slow bolometric responses to infrared radiation from a patterned high-T c superconducting (HTS) film in resistive and normal states deposited onto LaAlO3, NdGaO3, and MgO substrates were investigated using both pulse and modulation techniques. The response time of 35 ps to a laser pulse of 17 ps FWHM has been observed. The intrinsic response time of the fast process is expected to be about a few picoseconds. The modulation technique, being free from the disadvantages of pulse methods (poor sensitivity, limited dynamic range), makes the detailed study of a number of relaxation processes possible. Besides the nonequilibrium response, two kinds of bolometric processes, namely phonon transport through the film-substrate interface and phonon thermal diffusion in a substrate, manifest themselves in certain frequency dependences.  
  Address  
  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 0896-1107 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (up) Serial 1630  
Permanent link to this record
 
 
Author Gershenzon, E. M.; Gol'tsman, G. N.; Zorin, M. A.; Karasik, B. S.; Trifonov, V. A. url  openurl
  Title Nonequilibrium and bolometric response of YBaCuO films in a resistive state to infrared low intensity radiation Type Conference Article
  Year 1994 Publication Council on Low-temp. Phys. Abbreviated Journal Council on Low-temp. Phys.  
  Volume Issue Pages 82-83  
  Keywords YBCO HTS HEB  
  Abstract  
  Address Dubna  
  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 Joint Inst. for Nuclear Research, Dubna (Russian Federation); 296 p; 1994; p. 82-83; 30. Conference on low-temperature physics; 30. Soveshchanie po fizike nizkikh temperatur; Dubna (Russian Federation); 6-8 Sep 1994  
  Notes Неравновесный и болометрический отклик YBaCuO пленок в резиотивном состоянии на инфракрасное лазерное излучение малой интенсивности Approved no  
  Call Number (up) Serial 1632  
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Author Karasik, B.S.; Milostnaya, I.I.; Zorin, M.A.; Elantev, A.I.; Gol'tsman, G.N.; Gershenzon, E.M. url  doi
openurl 
  Title Subnanosecond S-N and N-S switching of YBCO film induced by current pulse Type Journal Article
  Year 1994 Publication Phys. C: Supercond. Abbreviated Journal Phys. C: Supercond.  
  Volume 235-240 Issue Pages 1981-1982  
  Keywords YBCO HTS switches  
  Abstract A transition of YBCO bridge 60 nm thick from superconducting to normal state induced by an abrupt current step has been studied. A subnanosecond stage has been observed during both S-N and N-S transition. The data obtained can be explained by hot-electron phenomena. On the basis of experimental results a prediction of picosecond switch performance has been made.  
  Address  
  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 0921-4534 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (up) Serial 1633  
Permanent link to this record
 
 
Author Gol'tsman, G. N.; Goghidze, I. G.; Kouminov, P. B.; Karasik, B. S.; Semenov, A. D.; Gershenzon, E. M. url  doi
openurl 
  Title Influence of grain boundary weak links on the nonequilibrium response of YBaCuO thin films to short laser pulses Type Journal Article
  Year 1994 Publication J. Supercond. Abbreviated Journal J. Supercond.  
  Volume 7 Issue 4 Pages 751-755  
  Keywords YBCO HTS detector, nonequilibrium response  
  Abstract The transient voltage response in both epitaxial and granular YBaCuO thin films to 80 ps pulses of YAG∶Nd laser radiation of wavelength 0.63 and 1.54 μm was studied. In the normal and resistive states both types of films demonstrate two components: a nonequilibrium picosecond component and a bolometric nanosecond one. The normalized amplitudes are almost the same for all films. In the superconducting state we observed a kinetic inductive response and two-component shape after integration. The normalized amplitude of the response in granular films is up to five orders of magnitude larger than in epitaxial films. We interpret the nonequilibrium response in terms of a suppression of the order parameter by the excess of quasiparticles followed by the change of resistance in the normal and resistive states or kinetic inductance in the superconducting state. The sharp rise of inductive response in granular films is explained both by a diminishing of the cross section for current percolation through the disordered network of Josephson weak links and by a decrease of condensate density in neighboring regions.  
  Address  
  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 0896-1107 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (up) Serial 1636  
Permanent link to this record
 
 
Author Danerud, M.; Winkler, D.; Lindgren, M.; Zorin, M.; Trifonov, V.; Karasik, B. S.; Gol’tsman, G. N.; Gershenzon, E. M. url  doi
openurl 
  Title Nonequilibrium and bolometric photoresponse in patterned YBa2Cu3O7−δ thin films Type Journal Article
  Year 1994 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.  
  Volume 76 Issue 3 Pages 1902-1909  
  Keywords YBCO HTS HEB detector, nonequilibrium response  
  Abstract Epitaxial laser deposited YBa2Cu3O7−δ films of ∼50 nm thickness were patterned into detectors consisting of ten parallel 1 μm wide strips in order to study nonequilibrium and bolometric effects. Typically, the patterned samples had critical temperatures around 86 K, transition widths around 2 K and critical current densities above 1×106A/cm2 at 77 K. Pulsed laser measurements at 0.8 μm wavelength (17 ps full width at half maximum) showed a ∼30 ps response, attributed to electron heating, followed by a slower bolometric decay. Amplitude modulation in the band fmod=100 kHz–10 GHz of a laser with wavelength λ=0.8 μm showed two different thermal relaxations in the photoresponse. Phonon escape from the film (∼3 ns) is the limiting process, followed by heat diffusion in the substrate. Similar relaxations were also seen for λ=10.6 μm. The photoresponse measurements were made with the film in the resistive state and extended into the normal state. These states were created by supercritical bias currents. Measurements between 75 and 95 K (i.e., from below to above Tc) showed that the photoresponse was proportional to dR/dT for fmod=1 MHz and 4 GHz. The fast response is limited by the electron‐phonon scattering time, estimated to 1.8 ps from experimental data. The responsivity both at 0.8 and 10.6 μm wavelength was ∼1.2 V/W at fmod=1 GHz and the noise equivalent power was calculated to 1.5×10−9 WHz−1/2 for the fast response.  
  Address  
  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 0021-8979 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (up) Serial 1637  
Permanent link to this record
 
 
Author Karasik, B. S.; Zorin, M. A.; Milostnaya, I. I.; Elantev, A. I.; Gol’tsman, G. N.; Gershenzon, E. M. url  doi
openurl 
  Title Evidence of subnanosecond transition stage in S-N current switching of YBaCuO films Type Conference Article
  Year 1994 Publication Proc. SPIE Abbreviated Journal Proc. SPIE  
  Volume 2160 Issue Pages 74-82  
  Keywords YBCO HTS switches  
  Abstract We report on a study of S-N and N-S current switching in high quality YBaCuO films deposited onto ZrO2 and NdGaO3 substrates. The films 60-120 nm thick prepared by laser ablation were structured into single strips and were provided with gold contacts. We monitored the time dependence of the resistance upon application of the voltage step on the film. Experiment performed within certain ranges of voltage amplitudes and temperatures showed the occurrence of the fast stage both in S-N (shorter than 300 ps) and N-S transition. We discuss the mechanism of switching taking into account the hot electron phenomena in YBaCuO. The contributions of various thermal processes in the subsequent stage of the resistance dynamic are also discussed. The basic limiting characteristics (average dissipated power, minimum work done for switching, maximum repetition rate) of a picosecond switch which is proposed to be developed are estimated.  
  Address  
  Corporate Author Thesis  
  Publisher SPIE Place of Publication Editor Buhrman, R.A.; Clarke, J.T.; Daly, K.; Koch, R.H.; Luine, J.A.; Simon, R.W.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference Superconductive Devices and Circuits  
  Notes Approved no  
  Call Number (up) Serial 1638  
Permanent link to this record
 
 
Author Lindgren, M.; Trifonov, V.; Zorin, M.; Danerud, M.; Winkler, D.; Karasik, B. S.; Gol’tsman, G. N.; Gershenzon, E.M. url  doi
openurl 
  Title Transient resistive photoresponse of YBa2Cu3O7−δ films using low power 0.8 and 10.6 μm laser radiation Type Journal Article
  Year 1994 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.  
  Volume 64 Issue 22 Pages 3036-3038  
  Keywords YBCO HTS HEB, nonequilibrium  
  Abstract Thin YBa2Cu3O7−δ laser deposited films were patterned into devices consisting of ten parallel 1 μm wide strips. Nonequilibrium picosecond and bolometric photoresponses were studied by the use of 17 ps full width at half‐maximum laser pulses and amplitude modulated radiation from an AlGaAs laser up to 10 GHz and from a CO2 laser up to 1 GHz. The time and frequency domain measurements were in agreement. The fast response can be explained by electron heating. The use of low optical power and a sensitive measurement system excluded any nonlinear transient processes and kinetic inductance changes in the superconducting state. At 1 GHz modulation frequency, the responsivity was ∼1.2 V/W both for 0.8 and 10.6 μm wavelengths. The sensitivity of a fast and spectrally broadband infrared detector is discussed.  
  Address  
  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 0003-6951 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number (up) Serial 1639  
Permanent link to this record
 
 
Author Karasik, B.S.; Lindgren, M.; Zorin, M.A.; Danerud, M.; Winkler, D.; Trifonov, V.V.; Gol’tsman, G.N.; Gershenzon, E.M. url  doi
openurl 
  Title Picosecond detection and broadband mixing of near-infrared radiation by YBaCuO films Type Conference Article
  Year 1994 Publication Proc. SPIE Abbreviated Journal Proc. SPIE  
  Volume 2159 Issue Pages 68-76  
  Keywords YBCO HTS HEB mixer  
  Abstract Nonequilibrium picosecond and bolometric responses of YBCO films 500 angstroms thick patterned into 20 X 20 micrometers 2 size structure to 17 ps laser pulses and modulated radiation of GaAs and CO2 lasers have been studied. The modulation frequencies up to 10 GHz for GaAs laser and up to 1 GHz for CO2 were attained. The use of small radiation power (1 – 10 mW/cm2 for cw radiation and 10 – 100 nJ/cm2 for pulse radiation) in combination with high sensitive read-out system made possible to avoid any non-linear transient processes caused by an overheating of sample above a critical temperature or S-N switching enhanced by an intense radiation. Responses due to the change of kinetic inductance were believed to be negligible. The only signals observed were caused by a small change of the film resistance either in the resistive state created by a bias current or in the normal state. The data obtained by means of pulse and modulation techniques are in agreement. The responsivity about 1 V/W was measured at 1 GHz modulation frequency both for 0.85 micrometers and 10.6 micrometers wavelengths. The sensitivity of high-Tc fast wideband infrared detector is discussed.  
  Address  
  Corporate Author Thesis  
  Publisher Spie Place of Publication Editor Nahum, M.; Villegier, J.-C.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference High-Temperature Superconducting Detectors: Bolometric and Nonbolometric  
  Notes Approved no  
  Call Number (up) Serial 1640  
Permanent link to this record
 
 
Author Gol’tsman, G. N.; Kouminov, P. B.; Goghidze, I. G.; Karasik, B. S.; Gershenzon, E. M. url  doi
openurl 
  Title Nonbolometric and fast bolometric responses of YBaCuO thin films in superconducting, resistive, and normal states Type Conference Article
  Year 1994 Publication Proc. SPIE Abbreviated Journal Proc. SPIE  
  Volume 2159 Issue Pages 81-86  
  Keywords YBCO HTS HEB, nonbolornetric  
  Abstract The transient voltage response in both epitaxial and granular YBaCuO thin films to 20 ps pulses of YAG:Nd laser radiation with 0.63 micrometers and 1.54 micrometers was studied. In normal and resistive states both types of films demonstrate two components: nonequilibrium picosecond component and following bolometric nanosecond. The normalized amplitudes are almost the same for all films. In superconducting state we observed a kinetic inductive response and two-component shape after integration. The normalized amplitude of the response in granular films is up to several orders of magnitude larger than in epitaxial films. We interpret the nonequilibrium response in terms of a suppression of order parameter by the excess of quasiparticles followed by the change of resistance in normal and resistive states or kinetic inductance in superconducting state. The sharp rise of inductive response in granular films is explained both by a diminishing of the crossection for current percolation through the disordered network os Josephson weak links and by a decrease of condensate density in neighboring regions.  
  Address  
  Corporate Author Thesis  
  Publisher SPIE Place of Publication Editor Nahum, M.; Villegier, J.-C.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference High-Temperature Superconducting Detectors: Bolometric and Nonbolometric  
  Notes Approved no  
  Call Number (up) Serial 1641  
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