Afterpulse-like phenomenon of superconducting single photon detector in high speed quantum key distribution system
We discuss our estimates of the performance of a superconducting single photon detector (SSPD) in a high speed quantum key distribution (QKD) system. We find that at high repetition operation reflections from the readout circuit at room temperature causes an afterpulse-like phenomenon, and drastically increases the quantum bit error rate (QBER). Such effects are not seen during low frequency operation. By using an amplifier with a small reflection coefficient S11, we succeed in reducing the afterpulse-like phenomenon and increasing a secure key rate.
- Optics Express
Optics Express 19(20), 19562-19571, 2011-09-26
Optical Society of America