The limitation of noise equivalent power by background radiation for infrared superconducting single photon detectors coupled to standard single mode optical fibers

 

K. Smirnov ^1,2,3, Y. Vachtomin ^1,2, A. Divochiy ², A. Antipov ², G. Goltsman ^1,2,3

 ¹ Moscow State Pedagogical University

 ² CJSC “Superconducting nanotechnology” (Scontel)

 ³ National Research University Higher School of Economics

 

The paper is received on April 20, 2015

 

Abstract. We investigated the minimum level of the dark count rates and noise equivalent power of superconducting single photon detectors coupled to standard single mode optical fibers. We found that background radiation limits the minimum level of the dark count rates. We also proposed the effective method for reducing background radiation out of the required spectral range of the detector. Measured noise equivalent power of detector reaches 8.9×10^-19 W×Hz^1/2 at a wavelength of 1.55 μm and quantum efficiency 35%.

Keywords: superconducting single photon detectors, dark counts, noise equivalent power, single mode fiber, background radiation.