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Santavicca, D. F., Reulet, B., Karasik, B. S., Pereverzev, S. V., Olaya, D., Gershenson, M. E., et al. (2010). Energy resolution of terahertz single-photon-sensitive bolometric detectors. Appl. Phys. Lett., 96(8), 083505-3.
Abstract: We report measurements of the energy resolution of ultrasensitive superconducting bolometric detectors. The device is a superconducting titanium nanobridge with niobium contacts. A fast microwave pulse is used to simulate a single higher-frequency photon, where the absorbed energy of the pulse is equal to the photon energy. This technique allows precise calibration of the input coupling and avoids problems with unwanted background photons. Present devices have an intrinsic full-width at half-maximum energy resolution of approximately 23 THz, near the predicted value due to intrinsic thermal fluctuation noise.
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Zhang, W., Khosropanah, P., Gao, J. R., Kollberg, E. L., Yngvesson, K. S., Bansal, T., et al. (2010). Quantum noise in a terahertz hot electron bolometer mixer. Appl. Phys. Lett., 96(11), 111113–(1–3).
Abstract: We have measured the noise temperature of a single, sensitive superconducting NbN hot electron bolometer (HEB) mixer in a frequency range from 1.6 to 5.3 THz, using a setup with all the key components in vacuum. By analyzing the measured receiver noise temperature using a quantum noise (QN) model for HEB mixers, we confirm the effect of QN. The QN is found to be responsible for about half of the receiver noise at the highest frequency in our measurements. The beta-factor (the quantum efficiency of the HEB) obtained experimentally agrees reasonably well with the calculated value.
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Tanner, M. G., Natarajan, C. M., Pottapenjara, V. K., O'Connor, J. A., Warburton, R. J., Hadfield, R. H., et al. (2010). Enhanced telecom wavelength single-photon detection with NbTiN superconducting nanowires on oxidized silicon. Appl. Phys. Lett., 96(22), 3.
Abstract: Superconducting nanowire single-photon detectors (SNSPDs) have emerged as a highly promising infrared single-photon detector technology. Next-generation devices are being developed with enhanced detection efficiency (DE) at key technological wavelengths via the use of optical cavities. Furthermore, new materials and substrates are being explored for improved fabrication versatility, higher DE, and lower dark counts. We report on the practical performance of packaged NbTiN SNSPDs fabricated on oxidized silicon substrates in the wavelength range from 830 to 1700 nm. We exploit constructive interference from the SiO2/Si interface in order to achieve enhanced front-side fiber-coupled DE of 23.2 % at 1310 nm, at 1 kHz dark count rate, with 60 ps full width half maximum timing jitter.
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Tuchak, A. N., Gol’tsman, G. N., Kitaeva, G. K., Penin, A. N., Seliverstov, S. V., Finkel, M. I., et al. (2012). Generation of nanosecond terahertz pulses by the optical rectification method. JETP Lett., 96(2), 94–97.
Abstract: The possibility of the generation of quasi-cw terahertz radiation by the optical rectification method for broad-band Fourier unlimited nanosecond laser pulses has been experimentally demonstrated. The broadband radiation of a LiF dye-center laser is used as a pump source of a nonlinear optical oscillator. The energy efficiency of terahertz optical frequency conversion in a periodically polarized lithium niobate crystal is 4 × 10−9 at a pump power density of 7 MW/cm2.
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Zinoni, C., Alloing, B., Li, L. H., Marsili, F., Fiore, A., Lunghi, L., et al. (2010). Erratum: “Single photon experiments at telecom wavelengths using nanowire superconducting detectors” [Appl. Phys. Lett. 91, 031106 (2007)]. Appl. Phys. Lett., 96(8), 089901.
Abstract: A calculation error was made in the original publication of this letter. The error was in the calculation of the noise equivalent power (NEP) values for the avalanche photodiode detector (APD) and the superconducting single photon detector (SSPD), the incorrect values were plotted on the right axis in Fig. 1(b). The correct NEP values were calculated with the same equation reported in the original letter and the revised Fig. 1(b) is shown below. The other conclusions of the paper remain unaltered.
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