光电工程, 2011, 38 (7): 54, 网络出版: 2011-08-10
CCD 强光饱和效应的温度因素分析
Temperature Impact on Saturation Effect of CCD Induced by Highlight
CCD 饱和效应 有限元分析 暗电流 像元饱和阈值 温度影响 CCD saturation effect finite element analysis dark-current pixel saturation threshold temperature influence
摘要
采用1.06 μm 的连续激光对可见光CCD 成像系统进行干扰实验,依次观察到了饱和串扰、串扰亮线加粗、全屏饱和与全屏布满黑白雪花点的实验现象。利用有限元分析的方法对实验中的探测器升温情况进行模拟计算。并通过数值分析,发现随着温度的升高,暗电流不断增大,当温度超过350 K 时,增大的速度显著上升;像元的饱和阈值相应地减小,当温度达到350 K 时,其数值就已经减为零。根据模拟升温的大小,结合温度升高时探测器暗电流、像元饱和阈值的变化,对实验现象进行了合理的解释。结果表明:除了考虑光电转换产生的光电子以外,由于激光辐照导致探测器表面升温,进而引起暗电流增大和像元饱和阈值减小,是CCD 产生饱和效应的重要影响因素。
Abstract
The experiment of 1.06 μm laser disturbing visible CCD image system was carried out, and the phenomenon of crosstalk, crosstalk expanding, full screen saturation and black-and-white spots distributing full screen were observed. With the method of finite element analysis, the temperature rise of detector induced by laser irradiating in the experiment above was simulated. Through numeric analysis, it was found that as temperature rose, dark-current increased while pixel saturation threshold decreased. Especially, when temperature was higher than 350 K, the trend was extremely enhanced. Considering the simulation outcome and changes of dark-current as well as pixel saturation threshold, the experiment phenomenon was properly explained. Results indicated that besides photoelectron produced by photoelectric conversion, the temperature rise induced by laser irradiating and corresponding changes of dark-current as well as pixel saturation threshold was important influencing factor to saturation effect of CCD.
郝向南, 聂劲松, 李化. CCD 强光饱和效应的温度因素分析[J]. 光电工程, 2011, 38(7): 54. HAO Xiang-nan, NIE Jing-song, LI Hua. Temperature Impact on Saturation Effect of CCD Induced by Highlight[J]. Opto-Electronic Engineering, 2011, 38(7): 54.