Illumination technique based on integrating sphere with an unequal radius, hyper-uniform luminance and large-field angle

In order to meet the measurement requirements of image sensors’ uniformity of the CCD system with a large-field angle, the design for the form and structure of the integrating sphere, with 600–800 mm and hyper-uniform luminance double hemisphere is presented. LightTools software is used for simulation. The simulation result indicates that the compact structure of the integrating sphere with asymmetric double hemisphere renders both the design values and systematic performance parameters superior to those of the common integrating sphere. The integrating sphere system designed is manufactured and its optical parameters are tested. The test result indicates that at the outlet of the integrating sphere, the variation of illuminance is less than 2.3%, and the variation of luminance on the inner surface is less than 4.4%. Hence, it is concluded that this system can be widely utilized in measuring image sensors’ uniformity of the photoelectric imaging system with a large-field angle.