摘要
铌酸锂晶体在3.2μm波段满足群速度匹配条件,可以在自发参量下转换(SPDC)过程中产生频域无关联光子对。但是,此时光子对在空间域通常为环状分布,降低了光子对的收集效率,从而降低光源亮度。如何让双光子在满足频域无关联的同时,处于空间单模状态,成为了一个亟需解决的问题。通过理论计算和数值模拟,对双光子的空间分布进行优化设计,发现周期极化铌酸锂和定制极化铌酸锂在特定波长和温度条件下,在SPDC中产生的双光子可在空间呈现类束状分布,施密特数可达1.170和1.150。本方案可为中红外波段的量子光学实验提供频域无关联和空间单模的量子光源。
Lithium niobate crystal satisfies the group-velocity-matching condition in 3.2μm wavelength band,enabling the generation of spectrally uncorrelated biphotons through spontaneous parametric down-conversion(SPDC).However,under this condition,the biphotons typically exhibit an annular distribution in the spatial domain,resulting in reduced photon collection efficiency and diminished source brightness.Therefore,achieving the frequency-uncorrelated and spatialsingle-mode states has become an urgent problem that needs to be addressed.In this study,through theoretical calculations and numerical simulations,the spatial distribution of biphotons was optimized.It was found that under specific wavelength and temperature conditions,the two-photons generated in SPDC by periodically polarized lithium niobate and custom polarized lithium niobate can exhibit a beam like distribution in space,with Schmidt number of 1.170 and 1.150.This approach offers a solution for quantum optical experiments in the mid-infrared wavelength range,by providing quantum light sources with frequency-uncorrelated and spatial single-mode characteristics.
作者
尤世欣
袁晨智
金锐博
You Shixin;Yuan Chenzhi;Jin Ruibo(Hubei Key Laboratory of Optical Information and Pattern Recognition,Wuhan Institute of Technology,Wuhan 430205,Hubei,China)
出处
《激光与光电子学进展》
CSCD
北大核心
2024年第11期136-143,共8页
Laser & Optoelectronics Progress
基金
国家自然科学基金(92365106,12074299)
湖北省自然科学基金杰出青年项目(2022CFA039)。
关键词
铌酸锂晶体
量子光源
自发参量下转换
类束状分布
群速度匹配
lithium niobate crystal
quantum light source
spontaneous parametric down-conversion
beamlike distribution
group-velocity-matching