基于单光子相位调制的多路复用密钥分发系统的研究

发布时间：2018-09-19 08:55

【摘要】：量子保密通信自提出以来由于其独特的安全性受到了全世界的广泛关注。在相位编码的量子保密通信中通过在单光子调制的相位上编码密钥,在接收端进行解调获得单光子携带的密钥。因为单光子的行为符合量子力学定理,所以由单光子充当载体的量子保密通信是绝对安全的。由于单光子调制的量子保密通信用于高频调制有很好的信噪比,在光纤量子通信中有很高的实用价值。基于副载波的多路复用量子密钥通信可以有效的提高系统的成钥率。在实际应用中,由于受外界噪声和实验条件的限制,需要解决系统快速锁定和容量分析的问题。本文基于单光子相位调制的多路复用密钥分发系统的研究,从实验上研究了单光子调制的频谱特性,实现了系统中FP腔的快速锁定。理论上研究了基于单光子调制的多路复用密钥分发系统的容量,实验上验证了多通道的响应。我们针对目前单光子相位调制的多路复用密钥分发系统存在的问题进行了如下工作研究：第一,提出了单光子调制方法,研究了单光子调制的频谱特性。同传统的光子计数调制相比,这种方法不仅可以用于实现高频调制也可以得到较高的信噪比,在实验中得到的信噪比高达122。应用这种单光子调制解调的方法我们实现了系统中FP腔的快速锁定。第二,通过研究副载波多路复用系统的量子比特误码率和成钥率来研究系统的容量,研究了通道相关参数的典型值和理论极限值对系统容量的影响。在实验上验证了多通道的响应,证明在调制深度为0.02的情况下,系统可以同时用于多个通道传输,通道之间没有串扰现象发生。
[Abstract]:Quantum secure communication has attracted worldwide attention for its unique security since it was proposed. In the phase coded quantum secure communication, the single photon carrier key is obtained by encoding the key on the phase of single photon modulation and demodulating at the receiving end. Because the behavior of single photon conforms to the quantum mechanics theorem, the quantum secure communication with single photon acting as carrier is absolutely safe. Because of the high signal-to-noise ratio (SNR) of single photon modulated quantum communication, it has high practical value in optical fiber quantum communication. Multi-channel multiplexing quantum key communication based on subcarrier can effectively improve the key rate of the system. In practical application, due to the limitation of external noise and experimental conditions, it is necessary to solve the problems of system fast locking and capacity analysis. Based on the research of multiplex key distribution system based on single photon phase modulation, the spectrum characteristics of single photon modulation are studied experimentally, and the fast locking of FP cavity in the system is realized. The capacity of multiplex key distribution system based on single photon modulation is studied theoretically and the response of multi-channel is verified experimentally. We have done the following research on the existing problems of the multiplex key distribution system with single photon phase modulation: first, we propose a single photon modulation method and study the spectrum characteristics of the single photon modulation. Compared with the traditional photon counting modulation, this method can not only be used to achieve high frequency modulation, but also can obtain higher SNR. The SNR obtained in the experiment is as high as 122. Using this method of single photon modulation and demodulation, we realize the fast locking of FP cavity in the system. Secondly, the capacity of the system is studied by studying the quantum bit error rate (QBER) and the key rate of the subcarrier multiplexing system, and the influence of the typical values of the channel related parameters and the theoretical limit values on the system capacity is studied. The multi-channel response is verified experimentally and it is proved that the system can be used to transmit multiple channels simultaneously when the modulation depth is 0.02 and there is no crosstalk between the channels.
【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN918.4;O413

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