| 1. |
- Tarasov, Mikhail, 1954, et al.
(författare)
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Nonthermal optical response of superconductor-insulator-normal metal-insulator-superconductor tunnel structures
- 2014
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Ingår i: Journal of Experimental and Theoretical Physics. - : Pleiades Publishing Ltd. - 1090-6509 .- 1063-7761. ; 119:1, s. 107-114
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Tidskriftsartikel (refereegranskat)abstract
- Bolometers, which are based on superconductor-insulator-normal metal-insulator-superconductor structures integrated into double slot antennas, are designed and fabricated. The change in the tunneling current in such structures during irradiation at a frequency of 330 GHz is experimentally studied at a temperature of about 0.1 K. It is found that, during irradiation, the energy distribution of electrons has a substantially nonequilibrium form, which differs from the Fermi distribution, and the main contribution to the addition to the tunneling current is made by the electrons that have no time to attain equilibrium within the electron system of the normal metal absorber. The characteristic electron and phonon relaxation times are estimated, and the estimates support the fact that the electron system is strongly nonequilibrium in the radiation field.
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| 2. |
- Tarasov, Mikhail, 1954, et al.
(författare)
-
Optical response of a cold-electron bolometer array
- 2010
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Ingår i: JETP Letters. - 1090-6487 .- 0021-3640. ; 92:6, s. 416-420
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Tidskriftsartikel (refereegranskat)abstract
- A multielement bolometric receiver system has been developed to measure the power and polarization of radiation at a calculated frequency of 345 GHz. Arrays of ten series-parallel connected cold-electron bolometers have been pairwise integrated into orthogonal ports of a cross-slot antenna. Arrays are connected in parallel in the high-frequency input signal and in series in the output signal, which is measured at a low frequency, and in a dc bias. Such an array makes it possible to increase the output resistance by two orders of magnitude as compared to an individual bolometer under the same conditions of high-frequency matching and to optimize the matching with the JFET amplifier impedance up to dozens of megohms. Parallel connection ensures matching of the input signal to the cross-slot antenna with an impedance of 30 Omega on a massive silicon dielectric lens. At a temperature of 100 mK, a response to the thermal radiation of a thermal radiation source with an emissivity of 0.3, which covers the input aperture of the antenna and is heated to 3 K, is 25 mu V/K. Taking into account real noise, the optical fluctuation dc sensitivity is 5 mK, the estimated sensitivity corresponding to the noise of the amplifier is about 10(-4) K/Hz(1/2), and the noise-equivalent power is about (1-5) x 10(-17) W/Hz(1/2).
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| 3. |
- Tarasov, Mikhail, 1954, et al.
(författare)
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Optical Response of a Cold-Electron Bolometer Array Integrated in a 345-GHz Cross-Slot Antenna
- 2011
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Ingår i: IEEE Transactions on Applied Superconductivity. - 1558-2515 .- 1051-8223. ; 21:6, s. 3635-3639
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Tidskriftsartikel (refereegranskat)abstract
- Two series/parallel arrays of ten cold-electronbolometers with superconductor–insulator–normal tunnel junctionswere integrated in orthogonal ports of a cross-slot antenna.To increase the dynamic range of the receiver, all single bolometersin an array are connected in parallel for the microwavesignal by capacitive coupling. To increase the output response,bolometers are connected in series for dc bias. With the measuredvoltage-to-temperature response of 8.8 μV/mK, absorbervolume of 0.08 μm3, and output noise of about 10 nV/Hz1/2,we estimated the dark electrical noise equivalent power (NEP)as NEP = 6∗ 10−18 W/Hz1/2. The optical response down toNEP = 2∗ 10−17 W/Hz1/2 was measured using a hot/cold loadas a radiation source and a sample temperature down to 100 mK.The fluctuation sensitivity to the radiation source temperature is1.3 ∗ 10−4 K/Hz1/2. A dynamic range over 43 dB was measuredusing a backward-wave oscillator, a variable polarization gridattenuator, and cold filters/attenuators.
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| 4. |
- Tarasov, Mikhail, 1954, et al.
(författare)
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Power Load and Temperature Dependence of Cold-Electron Bolometer Optical Response at 350 GHz
- 2014
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Ingår i: IEEE Transactions on Applied Superconductivity. - 1558-2515 .- 1051-8223. ; 24:6, s. 1-
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Tidskriftsartikel (refereegranskat)abstract
- Cold-electron bolometers (CEBs) integrated with twin-slot antennas have been designed and fabricated. Optical response was measured at bath temperatures of 0.06 to 3 K using blackbody radiation source at temperatures of 3 to 15 K. The responsivity of 0.3 * 10(9) V/W was measured at 2.7-K blackbody temperature that is close to the temperature of the cosmic microwave background. Optical measurements indicate quasi-optical coupling efficiency of up to 60% at low phonon temperature and low signal level. Estimations for bolometer responsivity were made for practical range of bath temperatures and blackbody radiation temperatures. The estimated ultimate dark responsivity at 100-mK bath temperature can approach S-V = 10(10) V/W and reduces down to 1.1 * 10(8) V/W at 300 mK for a device with absorber volume of 5 * 10(-20) m(3).
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