相干反馈实现非相敏放大器量子压缩特性增强的理论研究  

Theoretical Research on the Squeezing Enhancement from a Phase-insensitive Optical Amplifiers Using Coherent Feedback

作　　者：胡飞飞[1] 洪丹轲[1] 黄昱[1] 林旭斌 吴彤浩 韩亚帅 刘云 HU Fei-fei;HONG Dan-ke;HUANG Yu;LIN Xu-bin;WU Tong-hao;HAN Ya-shuai;LIU Yun(China Southern Power Grid Power Dispatch Control Center,Guangzhou 510000,China;Anhui Quantum Security Engineering Technology Research Center,Wuhu 241000,China)

机构地区：[1]中国南方电网电力调度控制中心,广东广州510000 [2]安徽省量子安全工程技术研究中心,安徽芜湖241000

出　　处：《量子光学学报》2024年第4期1-7,共7页Journal of Quantum Optics

基　　金：国家自然科学基金(12104013);南方电网科技项目(000005KK52220034(ZDKJXM2022036))。

摘　　要：基于原子四波混频的非相敏放大器是实验制备强度差压缩态光场的理想方案之一,提升其量子特性对于此非经典光场在量子信息和精密测量领域应用具有重要意义。利用分束器作为反馈控制器,将非相敏放大器输出的共轭光场部分反馈回真空端口,可实现其输出光场强度差压缩特性增强。针对相干反馈的非相敏放大器,本论文系统研究了其压缩增强效果随系统物理参数的依赖关系。研究结果表明,在忽略损耗的理想情况下,通过调控反馈控制器的反射率可实现无穷大的压缩增强效果。在实际实验系统的参数条件下,相干反馈系统依然可以实现显著的压缩增强。本论文研究成果可为基于相干反馈的非经典光场操控提供理论依据。Objective A phase-insensitive amplifier(PIA)based on atomic four-wave mixing is one of the ideal schemes for experimentally producing intensity-difference squeezed light.Improving its quantum properties is of great significance for the application of this non-classical light in the fields of quantum information and quantum precision measurement.By using a beam splitter as a feedback controller,the conjugated light from a PIA is partially fed back to the vacuum port,which can enhance the squeezing characteristics of its output intensity-difference squeezed light.This paper systematically investigates the dependence of the squeezing enhancement effect,induced by coherent feedback,on the physical parameters of the phase-insensitive amplifier.Our results indicate that in the ideal case of ignoring losses,infinite squeezing enhancement can be achieved by adjusting the reflectivity of the feedback controller. Under the parameter conditions of the actual experimental system, the PIA with coherent feedbackcan still realize significant squeezing enhancement. The research results can lay a theoretical foundation for the manipulation ofthe non-classical light field based on coherent feedback.Methods This paper focuses on the PIA based on the four-wave mixing process of 85Rb atoms. The conjugated light from a PIA ispartially fed back to the vacuum port. Based on the input-output relationship of the PIA and a beam splitter, the noise formula ofthe output intensity-difference squeezed light is finally obtained. Based on this, the dependence of the squeezing characteristicson physical system parameters is explored.Results and Discussions Based on the noise formula, the dependence of intensity-difference squeezing form the PIA on feedbackintensity, intensity gain, the absorption loss of the atomic vapor, and the optical loss of the feedback loop is numerically simulatedand presented in the paper. The paper delves into the impact of feedback on controlling the non-classical properties of the outputlight field from the PIA, both i

关 键 词：光参量放大器 压缩态光场 相干反馈 压缩增强 

分 类 号：O431.2[机械工程—光学工程]