摘要： 量子密钥分发采用的是偏振编码,用普通的单模光纤作为量子态传输的量子信道时,光纤会出现轻微的双折射效应,不能保持量子偏振态。为此,提出对量子态进行偏振补偿的方法。通过逐步逼近的方式,采用2个四分之一波片和1个半波片的旋转组合,实现对光纤的偏振补偿。通过测量得到系统的偏振对比度,并根据测量的结果逐步调整三波片的旋转角度,直到系统的偏振性能满足要求。仿真结果表明,与采用遍历方式的偏振补偿方法相比,逐步逼近的方法能更快地实现偏振补偿。

关键词: 偏振补偿, 逐步逼近, 遍历, 波片, 阈值, 偏振对比

Abstract: Quantum key distribution uses polarization coding.When using conventional single-mode fiber as the channel for quantum state transfer,optical fiber has a slight birefringence and cannot maintain the quantum state of polarization.In this case,this paper proposes a method to make polarization compensation for quantum state.Using the polarization compensation method of successive approximation,it is a promising scheme to complete the polarization compensation by rotating the combination of 2 quarter-wave plate and 1 half-wave plate successively.By measuring the values of polarization contrast ratio,it rotates the three wave plates according to the results of the measurement,until the polarization performance of the system finally meets the requirements.Experimental results show that compared with the polarization compensation method of traversal mode,the method of successive approximation can realize polarization compensation more quickly.

Key words: polarization compensation, successive approximation, traverse, wave plate, threshold, polarization contrast

中图分类号: 

• TP301.6