摘要
量子密钥分发融合经典通信方案将连续变量量子密钥分发和经典通信合并到了一起,为将来在现有的光网络上同时进行密钥分发和经典通信提供了一个有效的方法.然而,在量子信号上叠加一个经典信号将会给连续变量量子密钥分发系统引入过噪声从而大大降低系统的性能.本文提出基于光前置放大器的量子密钥分发融合经典通信方案,即在接收端插入光前置放大器来提升系统的性能.首先,在相同比特误码率条件下,光前置放大器对信号的放大能够降低对发送端经典信号调制振幅的要求,从而降低经典信号对量子信号的噪声影响;其次,光前置放大器能够补偿接收端探测器的不完美;再次,对于本地本振光的情形,放大器还能放大弱相位参考脉冲,从而降低参考脉冲散粒噪声带来的相位过噪声.在实际可达到的系统参数下,数值仿真结果表明本文提出的方案相比于原方案在安全密钥率和传输距离上都有很好的提升.这些结果表明本方案为量子密钥分发融合经典通信方案的进一步发展和实际应用提供了一个十分有效而实用的方法.
That the simultaneous quantum key distribution and classical communication(SQCC)scheme are combined with the continuous variable quantum key distribution(CVQKD)and the classical communication together,will provide an effective method to implement the simultaneous CVQKD and the classical communication in the existing optical networks in the future.However,superimposing a classical signal on the quantum signal will introduce excess noise into the CVQKD system,thus greatly reducing the performance of the system.In this paper,a novel scheme of SQCC based on optical preamplifier(OPA)is proposed,that is,the OPA is inserted into the receiver to improve the performance of the system.On the one hand,under the condition of the same bit error rate,the amplification of the signal by the OPA can reduce the requirement for the modulation amplitude of the classical signal at the sending end,thereby reducing the noise effect of the classical signal on the quantum signal.On the other hand,the OPA can compensate for the imperfection of the receiver detector.Moreover,in the case of locally generated local oscillator,the amplifier can also amplify the weak phase reference pulse,and thus reducing the phase excess noise caused by the shot noise of the weak phase reference pulse.Numerical simulation results show that the proposed scheme has better performance than the original scheme in the sense of security key rate and transmission distance.These results show that this scheme provides an effective and practical method for the further development and practical application of the SQCC scheme.
作者
钟海
叶炜
吴晓东
郭迎
Zhong Hai;Ye Wei;Wu Xiao-Dong;Guo Ying(School of Computer Science and Engineering,Central South University,Changsha 410083,China;School of Automation,Central South University,Changsha 410083,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2021年第2期298-305,共8页
Acta Physica Sinica
基金
国家自然科学基金(批准号:61871407,61872390,61801522)
中南大学研究生自主探索创新项目(批准号:2020zzts136)资助的课题.
关键词
连续变量
量子密钥分发融合经典通信
光前置放大器
continuous variable
simultaneous quantum key distribution and classical communication
optical preamplifier
