基于双光纤布拉格光栅滤波的量子密钥分发误码率分析

Quantum Key Distribution Analysis for Filtering Scheme Based on Double Fiber Bragg Grating

给出了偏振编码副载波复用量子密钥分发方案中的信号边带严格的表达式,并分析了调制过程中量子误码率的主要来源。基于此提出了一种基于双光纤布拉格光栅的量子密钥分发滤波方案,该方案采用两个光纤布拉格光栅反射端对向放置的结构设计,利用其极窄的反射谱将所需的信号频率从较强的杂波频率中滤出。仿真结果表明,该滤波结构能够有效地滤除副载波复用量子密钥分发系统中信号频率以外的互调边带,从而降低量子误码率。

A strict express of signal sideband in the polarization coding subcarrier multiplexing quantum key distribution scheme is presented. The source of quantum bit error rate in the modulation process is analyzed. A filtering scheme based on double fiber Bragg grating （FBG） for the polarization eo^ling subczrrier multiplexing quantum key distribution is presented. The reflection ends of these two FBG are placed toward each other. The reflection spectra are used to filter out the signal frequency from clutter frequency. The simulation results show that, the reflection structure can filter the intermodulation sideband except signal frequency and decrease the quantum bit error rate.