| |
Records |
Links |
|
Author |
Chulkova, G.; Milostnaya, I.; Korneev, A.; Minaeva, O.; Rubtsova, I.; Voronov, B.; Okunev, O.; Smirnov, K.; Gol’tsman, G.; Kitaygorsky, J.; Cross, A.; Pearlman, A.; Sobolewski, R.; Slysz, W. |
|
| |
Title |
Superconducting nanostructures for counting of single photons in the infrared range |
Type |
Conference Article |
| |
Year |
2005 |
Publication |
Proc. 2-nd CAOL |
Abbreviated Journal |
Proc. 2-nd CAOL |
|
| |
Volume |
2 |
Issue |
|
Pages  |
100-103 |
|
| |
Keywords |
SSPD, SNSPD |
|
| |
Abstract |
We present our studies on ultrafast superconducting single-photon detectors (SSPDs) based on ultrathin NbN nanostructures. Our SSPDs are patterned by electron beam lithography from 4-nm thick NbN film into meander-shaped strips covering square area of 10/spl times/10 /spl mu/m/sup 2/. The advances in the fabrication technology allowed us to produce highly uniform 100-120-nm-wide strips with meander filling factor close to 0.6. The detectors exploit a combined detection mechanism, where upon a single-photon absorption, an avalanche of excited hot electrons and the biasing supercurrent, jointly produce a picosecond voltage transient response across the superconducting nanostrip. The SSPDs are typically operated at 4.2 K, but they have shown that their sensitivity in the infrared radiation range can be significantly improved by lowering the operating temperature from 4.2 K to 2 K. When operated at 2 K, the SSPD quantum efficiency (QE) for visible light photons reaches 30-40%, which is the saturation value limited by optical absorption of our 4-nm-thick NbN film. For 1.55 /spl mu/m photons, QE was /spl sim/20% and decreases exponentially with the increase of the optical wavelength, but even at the wavelength of 6 /spl mu/m the detector remains sensitive to single photons and exhibits QE of about 10/sup -2/%. The dark (false) count rate at 2 K is as low as 2 /spl times/ 10/sup -4/ s/sup -1/, what makes our detector essentially a background-limited sensor. The very low dark-count rate results in the noise equivalent power (NEP) as low as 10/sup -18/ WHz/sup -1/2/ for the mid-infrared range (6 /spl mu/m). Further improvement of the SSPD performance in the mid-infrared range can be obtained by substituting NbN for the other, lower-T/sub c/ superconductors with the narrow superconducting gap and low quasiparticle diffusivity. The use of such materials will shift the cutoff wavelength towards the values even longer than 6 /spl mu/m. |
|
| |
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 |
Second International Conference on Advanced Optoelectronics and Lasers |
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1461 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Гершензон, Е. М.; Литвак-Горская, Л. Б.; Луговая, Г. Я.; Шапиро, Е. З. |
|
| |
Title |
Об интерпретации отрицательного магнитосопротивления в случае проводимости по верхней зоне Хаббарда в n-Ge⟨Sb⟩ |
Type |
Journal Article |
| |
Year |
1986 |
Publication |
Физика и техника полупроводников |
Abbreviated Journal |
Физика и техника полупроводников |
|
| |
Volume |
20 |
Issue |
1 |
Pages |
99-103 |
|
| |
Keywords |
n-Ge, Hubbard upper zone conductivity, negative magnetoresistance |
|
| |
Abstract |
В рамках теории квантовых поправок к проводимости объяснено отрицательное магнитосопротивление в n-Ge с концентрацией доноров Nd≃2.8⋅1016÷1.1⋅1017см−3, наблюдаемое в диапазоне температур 4.2−10 K, когда основной вклад в проводимость дают электроны верхней зоны Хаббарда. Показано, что время релаксации фазы волновой функции τφ определяется временем электрон-фононного взаимодействия τeph. |
|
| |
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 |
|
Serial |
1759 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Nikogosyan, A. S.; Martirosyan, R. M.; Hakhoumian, A. A.; Makaryan, A. H.; Tadevosyan, V. R.; Goltsman, G. N.; Antipov, S. V. |
|
| |
Title |
Effect of absorption on the efficiency of terahertz radiation generation in the metal waveguide partially filled with nonlinear crystal LiNbO3, DAST or ZnTe |
Type |
Journal Article |
| |
Year |
2019 |
Publication |
J. Contemp. Phys. |
Abbreviated Journal |
J. Contemp. Phys. |
|
| |
Volume |
54 |
Issue |
1 |
Pages |
97-104 |
|
| |
Keywords |
nonlinear crystal, THz, waveguide |
|
| |
Abstract |
The influence of terahertz (THz) radiation absorption on the efficiency of generation of coherent THz radiation in the system ‘nonlinear-optical crystal partially filling the cross section of a rectangular metal waveguide’ has been investigated. The efficiency of the nonlinear frequency conversion of optical laser radiation to the THz range depends on the loss in the system and the fulfillment of the phase-matching (FM) condition in a nonlinear crystal. The method of partially filling of a metal waveguide with a nonlinear optical crystal is used to ensure phase matching. The phase matching is achieved by numerical determination of the thickness of the nonlinear crystal, that is the degree of partial filling of the waveguide. The attenuation of THz radiation caused by losses both in the metal walls of the waveguide and in the crystal was studied, taking into account the dimension of the cross section of the waveguide, the degree of partial filling, and the dielectric constant of the crystal. It is shown that the partial filling of the waveguide with a nonlinear crystal results in an increase in the efficiency of generation of THz radiation by an order of magnitude, owing to the decrease in absorption. |
|
| |
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 |
1068-3372 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
|
Serial |
1289 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Nebosis, R. S.; Heusinger, M. A.; Semenov, A. D.; Lang, P. T.; Schatz, W.; Steinke, R.; Renk, K. F.; Gol'tsman, G. N.; Karasik, B. S.; Gershenzon, E. M. |
|
| |
Title |
Ultrafast photoresponse of an YBa2Cu3O7-δ film to far-infrared radiation pulses |
Type |
Journal Article |
| |
Year |
1993 |
Publication |
Opt. Lett. |
Abbreviated Journal |
Opt. Lett. |
|
| |
Volume |
18 |
Issue |
2 |
Pages |
96-97 |
|
| |
Keywords |
YBCO HTS detectors |
|
| |
Abstract |
We report the observation of an ultrafast photoresponse of a high-T(c), film to far-infrared radiation pulses. The response of a sample, consisting of a current-carrying structured YBa(2)Cu(3)O(7-delta) film cooled to liquid-nitrogen temperature, was studied by use of ultrashort laser pulses from an optically pumped far-infrared laser in the frequency range from 0.7 to 7 THz. We found that the response time was limited by the time resolution, 120 ps, of our electronic registration equipment. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0146-9592 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:19802049 |
Approved |
no |
|
| |
Call Number |
|
Serial |
1660 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Gershenzon, E. M.; Orlov, L. A.; Ptitsina, N. G. |
|
| |
Title |
Absorption spectra in electron transitions between excited states of impurities in germanium |
Type |
Journal Article |
| |
Year |
1975 |
Publication |
JETP Lett. |
Abbreviated Journal |
JETP Lett. |
|
| |
Volume |
22 |
Issue |
4 |
Pages |
95-97 |
|
| |
Keywords |
Ge, impurities, excited states, absorption spectra |
|
| |
Abstract |
|
|
| |
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 |
|
Serial |
1773 |
|
| Permanent link to this record |
