宽频带压缩态光场光学参量腔的设计  

Design of optical parametric cavity for broadband squeezed light field

作　　者：王俊萍 张文慧 李瑞鑫 田龙[1,2] 王雅君 郑耀辉[1,2] Wang Jun-Ping;Zhang Wen-Hui;Li Rui-Xin;Tian Long;Wang Ya-Jun;Zheng Yao-Hui(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,太原030006 [2]山西大学,极端光学协同创新中心,太原030006

出　　处：《物理学报》2020年第23期118-125,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:62027821,11654002,11874250,11804207);国家重点研发计划(批准号:2016YFA0301401);山西省三晋学者特聘教授项目;山西省重点研发计划(批准号:201903D111001);山西省“1331”重点建设学科;山西省高等学校中青年拔尖创新人才计划资助的课题.

摘　　要：压缩态光场是量子光学研究中的一种重要量子资源.在量子信息应用中,压缩态光场的频谱带宽是限制信息传输容量的重要指标.目前,光学参量振荡器是产生强压缩度非经典光场最有效的方法之一.本文通过分析输出耦合镜透射率、线宽、阈值功率对简并光学参量振荡器频谱带宽的影响,实验完成了低阈值(18 mW)、宽频带(84.2 MHz)、高稳定(锁定基线标准偏差为0.32 MHz)量子压缩器的设计.结果表明,相比单共振光学参量振荡器,双共振腔型具有低阈值、高稳定的特点,更适合于宽频带压缩态光场的制备与实际应用.The field of squeezed state is an important quantum resource in the study of quantum optics.In the application of quantum information,the spectrum bandwidth of the squeezed light field is an important index to limit the information transmission capacity.Currently,the optical parametric oscillator(OPO)is one of the most efficient ways to generate high squeezed non-classical optical fields.In this paper,the degenerate singlyresonant and doubly-resonant OPO structures are introduced.Both OPOs are composed of concave mirrors and periodically poled potassium titanyl phosphate crystals(PPKTP).The length of PPKTP crystal is 10 mm.The curvature radius of the curved surface is 12 mm,and it has high reflectivity at 1550 nm and 775 nm.The plane surface is coated with anti-reflection coating.The air gap length is 21 mm.The concave mirror is an output coupling mirror,and its radius of curvature is 25 mm.In the singly-resonant OPO,only the signal light resonates in the cavity,and the pump light passes through the nonlinear crystal twice and then outputs out of the cavity.The reflectivity of OPO output coupling mirror to the wavelength of 1550 nm is 88%.The linewidth of the corresponding fundamental frequency wave is 77.4 MHz.For doubly-resonant OPO,both the signal light and the pump light resonate simultaneously in the cavity.The reflectivity of OPO output coupling mirror to 1550 nm and 775 nm is 85%and 97.5%,respectively.The linewidth of the corresponding fundamental frequency wave and harmonic is 97.1 MHz and 15.6 MHz,respectively.Then the threshold of OPO is calculated.The threshold pump power of OPO increases with signal light transmittance increasing,but the threshold value of doubly-resonant OPO is obviously smaller than that of singly-resonant OPO.After that,the variation of the squeezing bandwidth of the squeezed light field generated by OPO with the transmittance of the signal is analyzed.Finally,we complete the design of quantum squeezer with low threshold(18 mW),broadband(84.2 MHz)and high stability(the standard dev

关 键 词：压缩态光场 光学参量振荡器 泵浦阈值 压缩带宽 

分 类 号：O431.2[机械工程—光学工程]