Plug and Play quantum key distribution system using differential phase shift
Xiuliang Chen, Chunyuan Zhou, Guang Wu, Xianghe Li, Heping Zeng · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2004
This report proposes a “Plug and Play” quantum key distribution system using differential phase shift, in which any birefringence effects and polarization-dependent losses in the telecom fiber are automatically compensated by using a Faraday mirror. In this system, a light pulse is split into three pulses after traveling through four couplers and a light intensity feedback servosystem is plugged into this system in order to adjust the phase shifter to compensate the variation of these three pulses. The efficiency of key creation in this system is 8/3 higher than the conventional cryptosystem based on the BB84 protocol.