Quantum Key Generation Based on Coding of Polarization States of Photons

摘要

This paper reports on the results of experimental investigations into the distribution of a quantum key on a setup designed for quantum cryptography with single photons. The quantum key is transmitted with pulsed semiconductor lasers by coding polarization states of photons in two alternative nonorthogonal bases. Silicon avalanche photodiodes (C30902S) serve as single-photon detectors. The rate of key generation is equal to 1.8 kbit/s when the clock frequency of laser pulse repetition is 100 kHz and the mean number of photons per pulse is approximately equal to 0.2. The number of errors in the key does not exceed 1%.