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Korneev, A., Divochiy, A., Marsili, F., Bitauld, D., Fiore, A., Seleznev, V., et al. (2008). Superconducting photon number resolving counter for near infrared applications. In P. Tománek, D. Senderáková, & M. Hrabovský (Eds.), Proc. SPIE (Vol. 7138, 713828 (1 to 5)). Spie.
Abstract: We present a novel concept of photon number resolving detector based on 120-nm-wide superconducting stripes made of 4-nm-thick NbN film and connected in parallel (PNR-SSPD). The detector consisting of 5 strips demonstrate a capability to resolve up to 4 photons absorbed simultaneously with the single-photon quantum efficiency of 2.5% and negligibly low dark count rate.
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Marsili, F., Bitauld, D., Fiore, A., Gaggero, A., Mattioli, F., Leoni, R., et al. (2010). Photon-number-resolution at telecom wavelength with superconducting nanowires. IntechOpen [DOI:10.5772/6920]. Retrieved June 26, 2024, from http://dx.doi.org/10.5772/6920
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Fiore, A., Marsili, F., Bitauld, D., Gaggero, A., Leoni, R., Mattioli, F., et al. (2009). Counting photons using a nanonetwork of superconducting wires. In M. Cheng (Ed.), Nano-Net (pp. 120–122). Berlin, Heidelberg: Springer Berlin Heidelberg.
Abstract: We show how the parallel connection of photo-sensitive superconducting nanowires can be used to count the number of photons in an optical pulse, down to the single-photon level. Using this principle we demonstrate photon-number resolving detectors with unprecedented sensitivity and speed at telecommunication wavelengths.
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Korneev, A., Korneeva, Y., Florya, I., Voronov, B., & Goltsman, G. (2011). Spectral sensitivity of narrow strip NbN superconducting single-photon detector. In J. Fiurásek, & I. Prochazka (Eds.), Proc. SPIE (Vol. 8072, 80720G (1 to 9)). SPIE.
Abstract: Superconducting single-photon detector (SSPD) is patterned from 4-nm-thick NbN film deposited on sapphire substrate as a 100-nm-wide strip. Due to its high detection efficiency, low dark counts, and picosecond timing jitter SSPD has become a competitor to the InGaAs avalanche photodiodes at 1550 nm and longer wavelengths. Although the SSPD is operated at liquid helium temperature its efficient single-mode fibre coupling enabled its usage in many applications ranging from single-photon sources research to quantum cryptography. In our strive to increase the detection efficiency at 1550 nm and longer wavelengths we developed and fabricated SSPD with the strip almost twice narrower compared to the standard 100 nm. To increase the voltage response of the device we utilized cascade switching mechanism: we connected 50-nm-wide and 10-μm-long strips in parallel covering the area of 10 μmx10 μm. Absorption of a photon breaks the superconductivity in a strip leading to the bias current redistribution between other strips followed their cascade switching. As the total current of all the strips about is 1 mA by the order of magnitude the response voltage of such an SSPD is several times higher compared to the traditional meander-shaped SSPDs. In middle infrared (about 3 μm wavelength) these devices have the detection efficiency several times higher compared to the traditional SSPDs.
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Maingault, L., Tarkhov, M., Florya, I., Semenov, A., Espiau de Lamaëstre, R., Cavalier, P., et al. (2010). Spectral dependency of superconducting single photon detectors. J. Appl. Phys., 107(11), 116103 (1 to 3).
Abstract: We investigate the effect of varying both incoming optical wavelength and width of NbN nanowires on the superconducting single photon detectors (SSPD) detection efficiency. The SSPD are current biased close to critical value and temperature fixed at 4.2 K, far from transition. The experimental results are found to verify with a good accuracy predictions based on the “hot spot model,” whose size scales with the absorbed photon energy. With larger optical power inducing multiphoton detection regime, the same scaling law remains valid, up to the three-photon regime. We demonstrate the validity of applying a limited number of measurements and using such a simple model to reasonably predict any SSPD behavior among a collection of nanowire device widths at different photon wavelengths. These results set the basis for designing efficient single photon detectors operating in the infrared (2–5 μm range).
This work was supported by European projects FP6 STREP “SINPHONIA” (Contract No. NMP4-CT-2005-16433) and IP “QAP” (Contract No. 15848).
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