微光像增强器信噪比理论极限问题研究  

Theoretical limit for SNR of LLL image intensifiers

作　　者：向世明[1] 

机构地区：[1]西安应用光学研究所第二研究室微光夜视技术国防科技重点实验室,陕西西安710065

出　　处：《应用光学》2008年第5期724-726,共3页Journal of Applied Optics

摘　　要：信噪比是微光像增强器的重要参数之一,其值的高低决定着微光成像系统在低照度条件下的探测距离和图像清晰度。根据线性系统信噪比链理论,借助系统噪声因子关系式,分析了微光像增强器的理论极限信噪比(S/N)limit。在系统各级不附加任何噪声(即NF=1),或仅受输入光子及光电子数涨落噪声限制的理想条件下,给出像管不同量子效率(η)之最大信噪比(S/N)limit的表达式;在η=1的极限情况下,求得该像管的理论极限信噪比(S/N)limit≤64。Signal-to-noise ratio （SNR） is an important parameter of image intensifiers, which determines the detection range and image quality of the photo-electronic imaging systems operating in low-light-level condition. On the basis of SNR chain theory of linear systems, the theoretical limiting SNR of the low-light-level image intensifier was analyzed by the noise factor expression of the system. The expression of maximum SNR for the photocathode quantum efficiency η is given in the precondition of no additional noise in each part of the system, that is NF=1, or in the ideal condition being restricted only by input photons and noise caused by the fluctuation of photoelectron quantity. The theoretical limiting SNR of the tube is≤64, which is derived under the limiting condition of η= 1.

关 键 词：微光像增强器 微通道板(MCP) 信噪比 噪声因子 

分 类 号：TN144-34[电子电信—物理电子学]