The effect of balanced homodyne detection on continuous variable quantum key distribution
平衡零拍测量对连续变量量子密钥分配的影响

Different from single photon quantum key distribution, continuous variable quantum key distribution uses the balanced homodyne detection. In this paper, the detection error of balanced homodyne caused by vacuum noise of the local light and unbalance of beam splitter is analyzed, the maximal safe distance limited by the electronic noise of balance homodyne detector is given, finally, the relationship between the noise of balanced homodyne detection and key rate are shown.