脉冲激光辐照可见光面阵CCD的入瞳衍射效应

采用波长为532nm的脉冲激光从31.5m的距离辐照可见光面阵电荷耦合器件(CCD),实验观察到了规律性圆环条纹的产生。通过增大激光束的入射角度、调节衰减倍率、重复频率和作用距离,研究了这些规律性圆环条纹的产生条件和机理。结果发现:保持激光器与CCD的作用距离31.5m不变,在激光束的入射角小于或者稍稍大于光学系统半视场角6.8°的情况下,只要光学系统入瞳处的功率密度达到10-3 W/cm2量级,就可以观察到规律性的圆环条纹。通过对探测器表面能量分布进行数学仿真,证实规律性的圆环条纹是由于光学系统入瞳的衍射效应而产生的。

Diffraction effect of entrance pupil by irradiating visible light array CCD with pulsed laser

The regular circular fringes could be observed when the visible array CCD was irradiated by 532 nm pulsed laser from a distance of 31.5 m. Their generating conditions and mechanism have been investigated by changing the incident angle, the attenuation factor, repetition frequency and distance. The experimental results show that in the premise that the incident angle of laser is smaller or a little larger than the half angle of view 6.8°, the regular circular fringes can be observed as long as the power density can reach 10^-3 W/cm² at the pupil of optical system. It was proved that the regular circular fringes were caused by the diffraction effect of the pupil of optical system, based on the simulation of energy distribution on the detector’s surface.