摘要
围绕小型条纹变像管,数值研究了光电阴极发射的光电子的初始能量及球面阴极曲率半径对物理时间分辨率及时间畸变的影响.结果表明:物理时间分辨率受光电子初始能量影响较大,受阴极曲率半径及离轴距离影响较小;离轴距离越大,时间畸变越大;平面型光电阴极在离轴8mm的物点处,时间畸变大于40ps;随着阴极曲率半径的减小,时间畸变逐渐由正值变为负值;当阴极曲率半径为70mm时,条纹管在整个阴极工作狭缝16mm内的时间畸变小于8ps;同时,在4.3ns全屏扫描时间条件下,光电阴极发射的狭缝像在荧光屏上几乎没有弯曲,且即使在离轴8mm的物点处,光电阴极空间分辨率仍可高达25lp/mm@MTF=10%.此外,实验测试了条纹变像管的静态空间分辨率、阴极积分灵敏度及条纹变像管的亮度增益特性.测试结果显示:光电阴极中心处空间分辨率高于28lp/mm,边缘处高于18lp/mm;阴极灵敏度为178μA/lm,亮度增益高于12,远高于具有相同探测面积的皮秒条纹变像管的亮度增益(亮度增益仅为0.5),在条纹管激光雷达领域具有较强的弱信号探测能力.
Based on the small-size streak tube,the dependence of the physical temporal resolution and temporal distortion on the factors including initial energy of electrons generated from the photocathode and spherical photocathode curvature radius is numerically simulated.The simulation results show that the physical temporal resolution is greatly affected by the initial energy,which is less affected by the spherical curvature radius and off-axis distance;the temporal distortion increases with the off-axis distance.Furthermore,the streak tube with a flat photocathode has a positive temporal distortion.With the decrease of the radius of curvature of the photocathode,the temporal distortion gradually changes from positive value to negative ones.And,when the photocathode curvature radius is 70 mm,the temporal distortion can be reduced to 8 ps and the spatial resolution can reach 25 lp/mm @ MTF=10%,the curvature of the slit image can be almost neglected even though the off-axis distance is 8 mm.Besides,the static spatial resolution and luminance gain of the streak tube,the luminance photocathode sensitivity of the photocathode are tested experimentally.The experiment results show that the spatial resolution of the streak tube is higher than 28 lp/mm at the photocathode center while it is higher than 18 lp/mm at the edge.The luminance photocathode sensitivity of the small-size streak tube is 178 μA/lm and the luminance gain is higher than 12 while the luminance gain of picosecond streak tube is only 0.5.Thus,the small-size streak tube has a good weak light detection ability in the field of streak tube imaging lidar.
作者
田丽萍
温文龙
王兴
陈萍
惠丹丹
卢裕
田进寿
赵卫
TIAN Li-ping;WEN Wen-long;WANG Xing;CHEN Ping;HUI Dan-dan;LU Yu;TIAN Jin-shou;ZHAO Wei(Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology,Xi′an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi′an 710119,China;University of Chinese Academy of Sciences,Beijing 100049,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2019年第7期54-60,共7页
Acta Photonica Sinica
基金
The National Natural Science Foundation of China(No.11805276)
the West Young Scientists Foundation of Chinese Academy of Sciences(No.XAB2017B12)
