CCD光电参数测试系统的研制

Development of measurement instrument for photoelectric parameters of CCD

研制了一套CCD光电参数测试系统，可实现对CCD的无效像元、相对光谱响应、响应度、等效噪声照度、动态范围、面响应度不均匀性等光电参数的全自动测试。CCD的相对光谱响应测试基于单光路直接比较法实现，而其他CCD光电参数的测试则基于特制的积分球光源。四个可独立开关的溴钨灯分别安置于四个次积分球内，经高精度电动光阑与主积分球级联，主积分球壁上的照度计经标定后可实时测试积分球光源出口照度值。该光源色温不变，可在大动态范围内以较高精度实现连续调节，满足CCD光电参数测试的需求。利用上述装置对E2V公司科学级CCD47-10B进行了实际测试，并分析了测量的不确定度。结果表明：相对光谱响应测试覆盖光谱范围400~1000 nm，不确定度为4.37%。光电转换参数测试装置距离光源出口23 mm处照度覆盖动态范围0~235 lx，Φ80 mm范围内照度均匀性达到99%,测试不确定度为4.9%。该系统可用于航天级CCD的光电参数测试及芯片甄选。

A measurement system for testing the photoelectric parameters of CCD was developed. It can realize automatic testing for the photoelectric parameters of various types of linear or area CCD, including invalid pixels, relative spectral responsivity, saturation irradiance, responsivity, equivalent noise irradiance, dynamic range, linearity, threshold illuminance, nonuniformity. The measurement system for relative spectral responsivity of CCD was based on the method of direct comparison of single optic path. The other parameters measurement system was built on a special designed integrating sphere light source. Four halogen lights was plant in four secondary integrating spheres, then cascaded with main integrating sphere using high-precision electric diaphragm. After calibrated, the light meter planted on the wall of main integrating sphere can test the luminance of export in real-time. The color temperature of the light source unchanged, the luminance of export was uniform, and can adjust in a large dynamic range continuously. The demand of testing the photoelectric parameters of CCD was satisfied. The photoelectric parameters of CCD47-10B was tested, and then the uncertainty of those systems was analyzed. Results indicate that the spectrum range of measurement system of relative spectral responsivity is 400-1 000 nm, the uncertainty is 4.37%. At the distance of 23 mm from exit port of source in measurement system for photoelectric transform parameters of CCD, the dynamic range of luminance was 0-235 lx, and the irradiance uniformity within Φ80 mm has reached 99%, the uncertainty is 4.9%. The measurement system can be used in testing the photoelectric parameters of aerospace-grade CCD and filtering it.