A superconducting single photon detector (SSPD) is promising candidate of the detector in a quantum key distribution (QKD) system, because of its low dark count and high speed repetition rate. We have developed the SSPD system cooled by a GM cryocooler. In this system, and the work surface can be cooled 2.95 K and up to 6 SSPDs can be installed. The active areas of SSPDs are 10×10 μm2 or 20×20 μm2, and the system detection efficiency at dark count rate of 100 Hz reached 2.6% at a wavelength of 1550 nm.

This content is only available via PDF.
You do not currently have access to this content.