Characterization of free-space quantum channels
Characterization of free-space quantum channels
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DOI：
10.1117/12.2320037
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发表时间：
2018-09
期刊：
影响因子：
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通讯作者：
D. Vasylyev;A. Semenov;W. Vogel
中科院分区：
文献类型：
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作者：
D. Vasylyev;A. Semenov;W. Vogel
量子光学中的许多基础和应用实验都需要远距离传输光的非经典态。在这种情况下，自由空间信道是光纤的一种非常有前途的替代方案，因为它们是移动的，并且能够使用卫星进行全球量子链路，与移动物体建立通信。对于这种信道，大气湍流是主要的干扰因素。透过率概率分布给出了湍流大气透过率脉动的统计特性。我们推导了大气量子信道的一致性光动力学方程，该方程逐步包含了各种大气效应，如光束漂移、光束展宽和光束变形为椭圆形、光束变形为任意形状。我们讨论了PDT模型的适用性不同的传播距离和光学湍流强度的情况下，当接收模块有一个环形孔径。分析了改善信道传输特性的最优检测和纠错策略。所得结果对于后选择和自适应策略等光学实验的设计以及自由空间量子通信协议的安全性分析具有重要意义。
Many fundamental and applied experiments in quantum optics require transferring nonclassical states of light through large distances. In this context the free-space channels are a very promising alternative to optical fibers as they are mobile and enable to establish communications with moving objects, using satellites for global quantum links. For such channels the atmospheric turbulence is the main disturbing factor. The statistical properties of the fluctuating transmittance through the turbulent atmosphere are given by the probability distribution of transmittance (PDT). We derive the consistent PDTs for the atmospheric quantum channels by step-by-step inclusion of various atmospheric effects such as beam wandering, beam broadening and deformation of the beam into elliptic form, beam deformations into arbitrary forms. We discuss the applicability of PDT models for different propagation distances and optical turbulence strengths in the case when the receiver module has an annular aperture. We analyze the optimal detection and correction strategies which can improve the channel transmission characteristics. The obtained results are important for the design of optical experiments including postselection and adaptive strategies and for the security analysis of quantum communication protocols in freespace.