Secure key distribution based on bidirectional Michelson interferometers
Qiuheng Song, Xin Quan Lai, Yongchao Chen, Hekuo Peng, Jiachen Guo, Hongyan Wu, Bo Jia · Optics Letters · 2021
A scheme based on bidirectional Michelson interferometers to distribute secret keys through the phase of light wave is proposed and demonstrated. The structure uses two optical cable transmission schemes, lasers of short coherent length, random phase drift, polarization random disturbance, and vibration positioning technology to ensure the safe transmission of the secret key. The feasibility of 80 km secret key transmission is verified by experiments. When the secret key is transmitted at the frequency of 200 kHz, the bit error rate is less than 0.3%, and the disturbance positioning accuracy is within $\pm {100}\;{\rm m}$.