脉冲展宽系统中的飞秒光电子传输成像特性  

Transmission and Imaging Characteristics of Femtosecond Photoelectrons in Pulse-Dilation System

作　　者：高海英[1] 白雁力[1] 姚荣彬[1] 王旬[2] 刘达见[1] Gao Haiying;Bai Yanli;Yao Rongbin;Wang Xun;Liu Dajian(National Demonstration Center for Experimental Education of Mechanical and Electrical Engineering Training,Guilin University of Electronic Technology,Guilin,Guangxi 541004,China;Institute of Information Technology,Guilin University of Electronic Technology,Guilin,Guangxi 541004,China)

机构地区：[1]桂林电子科技大学机电综合工程训练国家级实验教学示范中心,广西桂林541004 [2]桂林电子科技大学信息科技学院,广西桂林541004

出　　处：《激光与光电子学进展》2019年第12期221-227,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(11865007,61863008);广西自然科学基金(2018GXNSFAA281073);桂林电子科技大学校级重点项目(JGA201806)

摘　　要：设计了短磁聚焦脉冲展宽分幅相机模型,以脉冲展宽原理和光电子运动方程为基础,研究了飞秒光电子在脉冲展宽系统中的加速、传输和成像特性,分析了时空弥散,探讨了降低时空弥散影响的方法。结果表明:当脉冲展宽系统长500mm、展宽斜率为10V·ps^-1、加速电场为2kV·mm^-1时,传输时间弥散引起的总物理时间分辨率为1.62ps,占相机时间分辨率的70%;空间弥散为62.87μm,相机成像对比度降低了13.58%。提高加速电场能有效降低时空弥散对相机物理时间分辨率和成像对比度的影响。We designed and modeled a short-magnetic-focusing pulse-dilation framing camera.Based on the principle of pulse dilation and the equation of photoelectron motion, we studied the fs-photoelectron acceleration,transmission,and imaging characteristics in a pulse-dilation system.In addition,we analyzed the temporal-spatial dispersion and discussed the methods for its reduction.The simulated results show that when the pulse-dilation system has a length of 500 mm,agradient of dilation pulse of 10 V·ps-1,and an accelerating field of 2 kV·mm-1,the total physical-temporal resolution resulting from temporal dispersion is 1.62 ps,which is 70% of the temporal resolution of the camera.The spatial dispersion is 62.87μm,and the image contrast is reduced by 13.58%.Thus,the influence of temporal-spatial dispersion on physical-temporal resolution and imaging contrast can be effectively reduced by enhancing the accelerating field.

关 键 词：超快光学 诊断技术 脉冲展宽分幅相机 飞秒光电子 时间弥散 空间弥散 

分 类 号：TN143[电子电信—物理电子学] O536[理学—等离子体物理]