| 摘要 |
<p>Systems and methods for suppressing the unwanted detection of backscattered light in a two-way quantum key distribution (QKD) system (10) is disclosed. The system includes a first QKD station (Bob) that has laser sources (L1, L2, L3,...) that emit light at different wavelengths, and two or more single-photon detector (SPD) units (128, 138). In a two-way QKD system, backscattered light is typically generated in an optical fiber link (FL) connecting the first and second QKD stations (Bob and Alice) by the relatively strong outgoing optical pulses (Pn', Pn"). To prevent the backscattered light from interfering with the detection of the optical pulses returned from the second QKD station to the first, a controller (66) sequentially activates the different light sources while sequentially activating pairs of SPDS (130, 140; 132, 142; 134, 144) in the SPD units.</p> |
