自发参量下转换和倍频的光谱对比研究  

Comparative study on the spectra of spontaneous parametric down conversion and second harmonic generation

作　　者：谢涛 汪湄湄 袁晨智 金锐博[1] XIE Tao;WANG Meimei;YUAN Chenzhi;JIN Ruibo(Hubei Key Laboratory of Optical Information and Pattern Recognition,Wuhan Institute of Technology,Wuhan 430205,China)

机构地区：[1]武汉工程大学光学信息与模式识别湖北重点实验室,湖北武汉430205

出　　处：《中国测试》2024年第12期65-71,共7页China Measurement & Test

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)。

摘　　要：自发参量下转换(SPDC)和倍频(SHG)是两种非常重要的非线性光学效应。但是在以前的研究中,二者是分别进行研究的,缺少对二者区别和联系的对比研究。该文从频域的角度入手,以周期极化磷酸氧钛钾(PPKTP)晶体和三硼酸锂(LBO)晶体为例,在实验和理论上对SPDC和SHG的光谱分布进行对比研究。理论计算和实验测量结果表明:二者的频谱分布函数都可以用泵浦包络函数和相位匹配函数的乘积来获得,但是,在SHG中,泵浦包络函数和相位匹配函数是单变量函数,其频谱调节范围有限;而在SPDC中,泵浦包络函数(PEF)和相位匹配函数(PMF)是双变量函数,频谱分布有更大的调节范围。该研究有助于人们对SPDC和SHG的光谱有更深刻的认识,也可以很精确地指导人们在实验中选取所需的频谱宽度。Spontaneous parametric down conversion(SPDC)and second harmonic generation(SHG)represent two of the most significant nonlinear optical effects.However,in previous studies,the two were studied separately,and a comparative study of the differences and connections between them is lacking.This paper presents a comparative study of the spectral distributions of SPDC and SHG in the perspective of the frequency domain.The study employs periodically poled potassium titanyl phosphate(PPKTP)crystal and lithium borate(LBO)crystal as examples.Theoretical calculations and experimental measurements indicate that the spectral distribution functions of both can be obtained by the product of the pump envelope function(PEF)and the phase matching function(PMF).However,in SHG,the PEF and PMF are single-variable functions with a limited spectral tuning range,while in SPDC,the PEF and PMF are two-variable functions with a larger tuning range.This study provides a deeper understanding of the spectra of SPDC and SHG,as well as guidance on selecting the appropriate spectral width for experimental purposes.

关 键 词：自发参量下转换 倍频 相位匹配 光谱分布 

分 类 号：TB9[一般工业技术—计量学]