Koshelets, V. P., Borisov, V. B., Dmitriev, P. N., Ermakov, A. B., Filippenko, L. V., Khudchenko, A. V., et al. (2006). Integrated submillimeter receiver for TELIS. Joint International Workshop “Nanosensors and Arrays of Quantum Dots and Josephson Junctions for space applications”, 10th International Workshop “From Andreev Reflection to the Earliest Universe”, .
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Semenov, A., Il'yin, K., Siegel, M., Smirnov, A., Pavlov, S., Richter, H., et al. (2006). Intermediate frequency bandwidth of a hot-electron mixer: Comparision with bolometric models. In Proc. 17th Int. Symp. Space Terahertz Technol. (pp. 73–76). Paris, France.
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Kerman, A. J., Dauler, E. A., Keicher, W. E., Yang, J. K. W., Berggren, K. K., Gol’tsman, G., et al. (2006). Kinetic-inductance-limited reset time of superconducting nanowire photon counters. Appl. Phys. Lett., 88(11), 111116 (1 to 3).
Abstract: We investigate the recovery of superconducting NbN-nanowire photon counters after detection of an optical pulse at a wavelength of 1550nm, and present a model that quantitatively accounts for our observations. The reset time is found to be limited by the large kinetic inductance of these nanowires, which forces a tradeoff between counting rate and either detection efficiency or active area. Devices of usable size and high detection efficiency are found to have reset times orders of magnitude longer than their intrinsic photoresponse time.
The authors acknowledge D. Oates and W. Oliver (MIT Lincoln Laboratory), S.W. Nam, A. Miller, and R. Hadfield (NIST) and R. Sobolewski, A. Pearlman, and A. Verevkin (University of Rochester) for helpful discussions and technical assistance. This work made use of MIT’s shared scanning-electron-beam-lithography facility in the Research Laboratory of Electronics. This work is sponsored by the United States Air Force under Air Force Contract No. FA8721-05-C-0002. Opinions, interpretations, recommendations and conclusions are those of the authors and are not necessarily endorsed by the United States Government.
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Piotr슠Orleanski, Miroslaw슠Ciechanowicz, Malgorzata슠Michalska, Witold슠Nowosielski, Miroslaw슠Rataj, & Marek슠Winkler. (2006). LCU: the control unit dedicated for local oscillator subsystem in ESA HIFI/Herschel project. In Proc. SPIE (Vol. 6159).
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Walther, C., Scalari, G., Faist, J., Beere, H., & Ritchie, D. (2006). Low frequency terahertz quantum cascade laser operating from 1.6 to 1.8 THz. Appl. Phys. Lett., 89, 231121(1–3).
Abstract: The authors report a GaAs/Al0.1Ga0.9As quantum cascade laser based on a bound-to-continuum transition optimized for low frequency operation. High tunability of the gain curve is achieved by the Stark effect and laser emission is measured between 1.6 and 1.8 THz. Pulsed mode operation up to 95 K and continuous wave operation up to 80 K are reported. The dynamical range in current is as high as 43%.
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Rogalski, A. (2006). Material considerations for third generation photon detectors.
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Gol'tsman, G., Korneev, A., Minaeva, O., Antipov, A., Divochiy, A., Kaurova, N., et al. (2006). Middle-infrared to visible-light ultrafast superconducting single-photon detector. In Proc. ASC. Seattle.
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(2006). Millimetron project.
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Kitaygorsky, J., Komissarov, I., Jukna, A., Sobolewski, R., Minaeva, O., Kaurova, N., et al. (2006). Nanosecond, transient resistive state in two-dimensional superconducting stripes. In Proc. APS March Meeting (H38.13).
Abstract: We have observed, nanosecond-in-duration, transient voltage pulses, generated across two-dimensional (2-D) NbN stripes (width: 100--500 nm; thickness: 3.5--10 nm) of various lengths (1--500 μm), when the wires were completely isolated from the outside world, biased at currents close to the critical current, and kept at temperatures below the mean-field critical temperature Tco. In 2-D superconducting films, at temperatures below the Kosterlitz-Thouless transition, all vortices are bound and the resistance is zero. However, these vortices can get unbound when a large enough transport current is applied. The latter results in a transient resistive state, which manifests itself as spontaneous, 2.5--8-ns-long voltage pulses with the amplitude corresponding to the unbinding potential of a vortex pair. In our 100-nm-wide stripes, we have also observed the formation of phase slip centers (PSCs) at temperatures close to Tco, and a mixture of PSCs and unbound vortex-antivortex pairs at low temperatures.
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Gol'tsman, G., Maslennikov, S., Finkel, M., Antipov, S., Kaurova, N., Grishina, E., et al. (2006). Nanostructured ultrathin NbN film as a terahertz hot-electron bolometer mixer. In Proc. MRS (Vol. 935, 210 (1 to 6)).
Abstract: Planar spiral antenna coupled and directly lens coupled NbN HEB mixer structures are studied. An additional MgO buffer layer between the superconducting film and Si substrate is introduced. The buffer layer enables us to increase the gain bandwidth of a HEB mixer due to better acoustic transparency. The gain bandwidth is widened as NbN film thickness decreases and amounts to 5.2 GHz. The noise temperature of antenna coupled mixer is 1300 and 3100 K at 2.5 and 3.8 THz respectively. The structure and composition of NbN films is investigated by X-ray diffraction spectroscopy methods. Noise performance degradation at LO frequencies more than 3 THz is due to the use of a planar antenna and signal loss in contacts between the antenna and the sensitive NbN bridge. The mixer is reconfigured for operation at higher frequencies in a manner that receiver’s noise temperature is only 2300 K (3 times of quantum limit) at LO frequency of 30 THz.
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Rosfjord, K. M., Yang, J. K. W., Dauler, E. A., Kerman, A. J., Vikas Anant, Voronov, B. M., et al. (2006). Nanowire Single-photon detector with an integrated optical cavity and anti-reflection coating. Opt. Express, 14(2), 527–534.
Abstract: We have fabricated and tested superconducting single-photon detectors and demonstrated detection efficiencies of 57% at 1550-nm wavelength and 67% at 1064 nm. In addition to the peak detection efficiency, a median detection efficiency of 47.7% was measured over 132 devices at 1550 nm. These measurements were made at 1.8K, with each device biased to 97.5% of its critical current. The high detection efficiencies resulted from the addition of an optical cavity and anti-reflection coating to a nanowire photodetector, creating an integrated nanoelectrophotonic device with enhanced performance relative to the original device. Here, the testing apparatus and the fabrication process are presented. The detection efficiency of devices before and after the addition of optical elements is also reported.
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(2006). ORNL developed infrared laser and modulator technology for last mile internet.
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Baryshev A., Hovenier J.N., Adam A.J.L., Kašalynas I., Gao J.R., Klaassen T.O., et al. (2006). Phase locking and spectral linewidth of a two-mode terahertz quantum cascade laser. Physics Letters, 89.
Abstract: We have studied the phase locking and spectral linewidth of an ~ 2.7 THz quantum cascade laser by mixing its two lateral lasing modes. The beat signal at about 8 GHz is compared with a microwave eference by applying conventional phase lock loop circuitry with feedback to the laser bias current. Phase locking has been demonstrated, resulting in a narrow beat linewidth of less than 10 Hz. Under requency stabilization we find that the terahertz line profile is essentially Lorentzian with a minimum linewidth of ~ 6.3 kHz. Power dependent measurements suggest that this linewidth does not approach the Schawlow-Townes limit.
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Hovenier J.N., Adam A.J.L., Kašalynas I., Gao J.R., Klaassen T.O., Baryshev A., et al. (2006). Phase-locking on the beat signal of a two-mode 2.7 terahertz metal-metal quantum cascade laser. In Proc. Symp. IEEE/LEOS Benelux Chapter (pp. 125–128).
Abstract: We have studied the linewidth and phase-locking of a 2.7 THz quantum cascade laser by using a superconducting bolometer mixer. The 8 GHz beat signal is compared with a microwave reference with a feedback to the laser bias current. Phase locking has been demonstrated, resulting in an extremely narrow beat linewidth of less than 10 Hz. Under frequency-stabilization conditions we find that the line profile is virtually Lorentzian with a long-term minimum linewidth of the THz modes of about 6.3 kHz. Temperature dependent measurements suggestthat this linewidthdoes not approach the Schawlow-Townes limit.
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Stevens, M., Hadfeld, R., Schwall, R., Nam, S. W., & and Mirin, R. (2006). Quantum dot single photon sources studied with superconducting single photon detectors. IEEE J. Sel. Topics Quantum Electron., 12(6), 1255–1267.
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