连续变量光纤量子信息处理中光纤信道额外噪声的影响与抑制  

The Influence and Suppression of Additional Noise in Fiber Channel in Continuous Variable Fiber-based Quantum Information Processing

作　　者：程琳[1] 冯晋霞[1,2] 李渊骥 张宽收[1,2] CHENG Lin;FENG Jin-xia;LI Yuan-ji;ZHANG Kuan-shou(State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Opto-Electronics,Shanxi University,Taiyuan,030006,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan,030006,China)

机构地区：[1]山西大学光电研究所量子光学与光量子器件国家重点实验室,山西太原030006 [2]山西大学极端光学协同创新中心,山西太原030006

出　　处：《量子光学学报》2024年第3期62-69,共8页Journal of Quantum Optics

基　　金：国家自然科学基金(62175135);山西省基础研究计划资助项目(202103021224025)。

摘　　要：本文主要开展了基于光纤信道的连续变量量子信息处理中光纤信道额外噪声的研究,首先从理论和实验上研究了光通信波段1550nm光场在光纤信道中由于声导波布里渊散射效应(GAWBS)引起的额外噪声的影响,理论计算出影响GAWBS效应引起额外噪声的关键参数一散射效率,并在实验上在不同距离光纤信道环境进行验证。在低本底振荡(LO)光功率和短光纤传输距离条件下,GAWBS散射效率与典型值基本一致。但随着LO光功率和光纤传输距离增加,GAWBS散射效率随之增大。在LO光功率为3mW,光纤传输距离为20km时,散射效率增大到典型值的8倍。在此基础上,利用脉冲调制LO光的方案抑制光纤信道的额外噪声,并在实验上验证该方案对光纤信道额外噪声抑制的影响因素。利用该方案,压缩度为3dB的1550nm压缩真空态光场在单模光纤中传输距离由7km提高至为15km。Objective In the process of continuous variable quantum information processing,the quantum state light field is usually transmitted and distributed through quantum channels.Quantum channel includes free space channel and optical fiber channel.Free space channel depends on weather conditions,atmospheric disturbance,etc.,and has high requirements on technology a cost.The fiber channel is highly compatible with the existing classical fiber communication system.It has the advantages of no electromagnetic interference,long relay distance and large transmission capacity,and is the best quantum channel for constructing metropolitan and intercity quantum networks.Telecommunication wavelengths of 1550 nm and 1342 nm correspond to the lowest loss and lowest dispersion window of fiber channel,respectively.The non-classical light fields of these two wavelengths are the ideal quantum light sources in quantum information processing over fiber.However,the decoherence effect caused by the interaction between the continuous variable quantum state field and the fiber channel is an unavoidable problem.Methods In this paper,the influence and suppression methods of the excess noise in fiber channel in fiber-based continuous variable quantum information processing are investigated.Firstly,the excess noise of fiber channel in continuous variable quantum information processing based on fiber channel is studied.In a specific frequency range,the power of extra noise under different optical fiber lengths and different background optical power is measured.The relationship between the scattering efficiency and the power and the optical fiber length is studied theoretically and experimentally.At the same time,the crosstalk effect of 1342 nm and 1550 nm optical field on 1550 nm channel is studied.Then,the scheme of pulse modulated LO light is used to suppress the excess noise of fiber channel,and the influencing factors of this scheme on the suppression of excess noise of fiber channel are verified experimentally.Results and Discussions The fi

关 键 词：连续变量量子通信 光纤信道 压缩态光场 额外噪声 

分 类 号：O437.1[机械工程—光学工程]