非临界压缩光场探测的实验方案研究  

Experimental scheme of non-critical squeezed light field detection

作　　者：刘鹏 李娟 项晓[1] 曹明涛 董瑞芳[1,2] 刘涛 张首刚[1,2] Liu Peng;Li Juan;Xiang Xiao;Cao Ming-Tao;Dong Rui-Fang;Liu Tao;Zhang Shou-Gang(Key Laboratory of Time and Frequency Primary Standards,National Time Service Center,Chinese Academy of Sciences,Xi’an 710600,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院国家授时中心,中国科学院时间频率基准重点实验室,西安710600 [2]中国科学院大学天文与空间科学学院,北京100049

出　　处：《物理学报》2022年第1期11-17,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12033007,61875205,61801458,91836301);中国科学院前沿科学重点研究项目(批准号:QYZDBSW-SLH007)、中国科学院战略性先导科技专项C类项目(批准号:XDC07020200)、中国科学院“西部青年学者”项目(批准号:XAB2019B17,XAB2019B15)和中国科学院重点项目(批准号:ZDRW-KT-2019-1-0103)资助的课题。

摘　　要：压缩态光场作为一种重要的量子光源,在量子计算、量子通信、精密测量等领域有广泛的应用前景.在非临界压缩光场产生的理论预测中,阈值以上泵浦的简并光学参量振荡器(DOPO)产生横向空间分布为一阶厄米高斯模式的非临界压缩光场,具有对泵浦光功率波动鲁棒性的量子特性,因此在实验中具有重要的应用价值.然而该非临界压缩光场的横向幅角随机旋转,导致无法利用本底探针光对其压缩特性进行稳定的平衡零拍实验探测.本文提出利用DOPO同时产生的与压缩光场空间正交的明亮光场作为本底探针光的实验探测方案.理论分析表明,该方案虽然引入了真空噪声,但可以很好地抵消压缩光场空间模式随机旋转引入的探测输出动态波动,得到3 d B的稳定探测结果,且对本底探针光的相位波动具有鲁棒性.因此该探测方案对于非临界压缩光场的实验研究具有重要的实用价值.The squeezed state, as an important quantum resource, has great potential applications in quantum computing, quantum communication and precision measurement. In the noncritically squeezed light theory, the predicted noncritically squeezed light can be generated by breaking the spontaneous rotational symmetry occurring in a degenerate optical parametric oscillator(DOPO) pumped above threshold. The reliability of this kind of squeezing is crucially important, as its quantum performance is robust to the pump power in experiment. However, the detected squeezing degrades rapidly in detection, because the squeezed mode orientation diffuses slowly, resulting in a small mode mismatch during the homodyne detection. In this paper,we propose an experimentally feasible scheme to detect noncritically squeezing reliable by employing the spatial mode swapping technic. Theoretically, the dynamic fluctuation aroused by random mode rotation in the squeezing detection can be compensated for perfectly, and 3 dB squeezing can be achieved robustly even with additional vacuum noise. Our scheme makes an important step forward for the experimental generation of noncritically squeezed light.

关 键 词：非临界 压缩光场 自发旋转对称破缺 

分 类 号：O431.2[机械工程—光学工程]