非线性超快成像技术的时间分辨率探究  

The temporal resolutions of the ultrafast imaging technologies based on nonlinear optics

作　　者：郑麦杰 陈振宽 王聪颖 曾选科[1] 文侨[1] 蔡懿[1] 徐世祥[1] 李景镇[1] ZHENG Maijie;CHEN Zhenkuan;WANG Congying;ZENG Xuanke;WEN Qiao;CAI Yi;XU Shixiang;LI Jingzhen(College of Physics and Optoelectronic Engineering,Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province,Shenzhen Key Laboratory of Micro-Nano Photonic Information Technology,Shenzhen University,Shenzhen 518060,Guangdong Province,P.R.China)

机构地区：[1]深圳大学物理与光电工程学院,光电子器件与系统教育部/广东省重点实验室,深圳市微纳光子信息技术重点实验室,广东深圳518060

出　　处：《深圳大学学报（理工版）》2022年第4期383-389,共7页Journal of Shenzhen University(Science and Engineering)

基　　金：国家自然科学基金资助项目(92050203,61925507,12174264,12004261,62075138,61827815);广东省自然科学基金资助项目(2020A1515010541);深圳市基础研究计划资助项目(JCYJ20200109105606426,JCYJ 20190808164007485,JCYJ20190808121817100,JCYJ20190808143419622,JCYJ20190808115601653)。

摘　　要：理论研究了基于非线性光学开关效应取样的超快成像技术.推导了基于倍频、光克尔效应及光参量放大等非线性过程取样方式下的开关函数表达式.提出等效曝光时间概念,用于准确描述基于不同非线性光学取样方式超快成像的实际时间分辨能力,对以超快旋转光场为目标物的超快成像过程进行模拟.结果表明,基于倍频的超快成像等效曝光时间与取样激光脉冲宽度相当;基于光克尔效应的超快成像等效曝光时间是取样脉宽的0.7倍,而基于光参量放大的等效曝光时间与取样脉宽和增益大小都有关.增益越高,等效曝光时间越短,超快测量时间分辨越高.当增益为1000时,等效曝光时间降低至取样脉宽的一半.研究结果为提升现有非线性光开关超快成像技术的时间分辨能力提供一条有效技术途径.We theoretically study some ultra-fast imaging technologies based on nonlinear optical switching effect sampling,and derive the expressions of switching functions based on nonlinear process sampling methods such as second harmonic(SH),optical Kerr effect and optical parametric amplification(OPA).For the first time,we propose a new concept,named equivalent exposure time(EET),which is used to describe accurately the actual gating time during ultrafast imaging.By using the ultra-fast rotating light fields as the targets,the simulations show that the EET of the ultrafast imaging based on SH is equivalent to the sampling laser pulse width,but the EET of the ultrafast imaging based on optical Kerr effect is 0.7 times of the sampling pulse width,while for the ultrafast imaging based on OPA,the EET depends on both the sampling pulse width and the gain.The higher the gain is,the shorter the EET,thus the higher the temporal resolution.The EET is reduced to half of the sampling pulse width when the OPA gain is 1000.This research provides an effective way to improve the temporal resolution of the ultrafast imaging via the nonlinear optical switches.

关 键 词：应用物理学 超快成像 超短激光脉冲 光开关 曝光时间 时间分辨率 光参量放大 

分 类 号：O59[理学—应用物理] O437.4[理学—物理]