@InProceedings{Goltsman_etal2005, author="Goltsman, G. and Korneev, A. and Minaeva, O. and Rubtsova, I. and Chulkova, G. and Milostnaya, I. and Smirnov, K. and Voronov, B. and Lipatov, A. P. and Pearlman, A. J. and Cross, A. and Slysz, W. and Verevkin, A. A. and Sobolewski, R.", editor="Razeghi, M. and Brown, G. J.", title="Advanced nanostructured optical NbN single-photon detector operated at 2.0 K", booktitle="Proc. SPIE", year="2005", publisher="Spie", volume="5732", pages="520--529", optkeywords="NbN SSPD; SNSPD", abstract="We present our studies on quantum efficiency (QE), dark counts, and noise equivalent power (NEP) of the latest generation of nanostructured NbN superconducting single-photon detectors (SSPDs) operated at 2.0 K. Our SSPDs are based on 4 nm-thick NbN films, patterned by electron beam lithography as highly-uniform 100{\textdiv}120-nm-wide meander-shaped stripes, covering the total area of 10x10 $\mu$m$^{2}$ with the meander filling factor of 0.7. Advances in the fabrication process and low-temperature operation lead to QE as high as ~30-40{\%} for visible-light photons (0.56 $\mu$m wavelength)-the saturation value, limited by optical absorption of the NbN film. For 1.55 $\mu$m photons, QE was ~20{\%} and decreased exponentially with the wavelength reaching ~0.02{\%} at the 5-$\mu$m wavelength. Being operated at 2.0-K temperature the SSPDs revealed an exponential decrease of the dark count rate, what along with the high QE, resulted in the NEP as low as 5x10$^{-21}$ W/Hz$^{-1/2}$, the lowest value ever reported for near-infrared optical detectors. The SSPD counting rate was measured to be above 1 GHz with the pulse-to-pulse jitter below 20 ps. Our nanostructured NbN SSPDs operated at 2.0 K significantly outperform their semiconducting counterparts and find practical applications ranging from noninvasive testing of CMOS VLSI integrated circuits to ultrafast quantum communications and quantum cryptography.", optnote="exported from refbase (https://db.rplab.ru/refbase/show.php?record=1478), last updated on Mon, 17 May 2021 22:09:55 -0500", doi="10.1117/12.590455", opturl="https://doi.org/10.1117/12.590455" }