Yates, S. J. C., Baryshev, A. M., Baselmans, J. J. A., Klein, B., & Güsten, R. (2009). Fast Fourier transform spectrometer readout for large arrays of microwave kinetic inductance detectors. Appl. Phys. Lett., 95(4), 3.
Abstract: Microwave kinetic inductance detectors have great potential for large, very sensitive detector arrays for use in, for example, submillimeter imaging. Being intrinsically readout in the frequency domain, they are particularly suited for frequency domain multiplexing allowing ~1000 s of devices to be readout with one pair of coaxial cables. However, this moves the complexity of the detector from the cryogenics to the warm electronics. We present here the concept and experimental demonstration of the use of fast Fourier transform spectrometer readout, showing no deterioration of the noise performance compared to the low noise analog mixing while allowing high multiplexing ratios.
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Mannino, G., Spinella, C., Ruggeri, R., La Magna, A., Fisicaro, G., Fazio, E., et al. (2010). Crystallization of implanted amorphous silicon during millisecond annealing by infrared laser irradiation. Appl. Phys. Lett., 97(2), 3.
Abstract: We investigated the homogenous nucleation of crystalline grains in amorphous Si during transient temperature pulse of few milliseconds IR laser irradiation. The crystallized volume fraction is ~80%. Significant crystallization occurs in nonsteady regime because of the rapid temperature variation (106 °C/s). Our model combines the time evolution of the crystal grain population with the consumption of the amorphous volume due to the growth of grains. Thanks to the experimental approach based on a laser source to heat α-Si and the theoretical model we extended the description of the spontaneous crystallization up to 1323 K or 250 K above the temperature investigated by conventional annealing.
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Gaggero, A., Nejad, S. J., Marsili, F., Mattioli, F., Leoni, R., Bitauld, D., et al. (2010). Nanowire superconducting single-photon detectors on GaAs for integrated quantum photonic applications. Appl. Phys. Lett., 97(15), 3.
Abstract: We demonstrate efficient nanowire superconducting single photon detectors (SSPDs) based on NbN thin films grown on GaAs. NbN films ranging from 3 to 5 nm in thickness have been deposited by dc magnetron sputtering on GaAs substrates at 350 °C. These films show superconducting properties comparable to similar films grown on sapphire and MgO. In order to demonstrate the potential for monolithic integration, SSPDs were fabricated and measured on GaAs/AlAs Bragg mirrors, showing a clear cavity enhancement, with a peak quantum efficiency of 18.3% at λ = 1300 nm and T = 4.2 K.
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Cao, Q., Yoon, S. F., Tong, C. Z., Ngo, C. Y., Liu, C. Y., Wang, R., et al. (2009). Two-state competition in 1.3 μm multilayer InAs/InGaAs quantum dot lasers. Appl. Phys. Lett., 95(19), 3.
Abstract: The competition of ground state (GS) and excited state (ES) is investigated from the as-grown and thermally annealed 1.3 μm ten-layer p-doped InAs/GaAs quantum dot (QD) lasers. The modal gain competition between GS and ES are measured and analyzed around the ES threshold characteristics. Our results show that two-state competition is more significant in devices with short cavity length operating at high temperature. By comparing the as-grown and annealed devices, we demonstrate enhanced GS and suppressed ES lasing from the QD laser annealed at 600 °C for 15 s.
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Baek, B., Lita, A. E., Verma, V., & Nam, S. W. (2011). Superconducting a-WxSi1–x nanowire single-photon detector with saturated internal quantum efficiency from visible to 1850 nm. Appl. Phys. Lett., 98(25), 3.
Abstract: We have developed a single-photon detector based on superconducting amorphous tungsten–silicon alloy (a-WxSi1–x) nanowire. Our device made from a uniform a-WxSi1–x nanowire covers a practical detection area (16 μm×16 μm) and shows high sensitivity featuring a plateau of the internal quantum efficiencies, i.e., efficiencies of generating an electrical pulse per absorbed photon, over a broad wavelength and bias range. This material system for superconducting nanowire detector technology could overcome the limitations of the prevalent nanowire devices based on NbN and lead to more practical, ideal single-photon detectors having high efficiency, low noise, and high count rates.
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