Experimental study on surface defect measurement of ultra-precision curved optical components

With the continuous development of advanced optical manufacturing method, ultra-precision optical components are widely used in aerospace, microelectronic equipment, optical precision measurement and other major application fields. Surface defect is one of the key parameters of ultra-precision optical components. It can be challenging to the surface defect measurement method of ultra-precision curved optical components. Optical micro-imaging measurement method is an effective defect measurement device. Illumination system optimization is one of the key technologies. This paper mainly provided the experimental results of the surface defect measurement of typical curved optical components with microscopic imaging, analyzed the influence of different light source types, different illumination angles, different illumination brightness and other parameters on the imaging effect of curved surface defects, and the comparative experiments of various types of curved optical components were carried out. The experimental results were analyzed and discussed from the aspects of image contrast, light uniformity, and capacity of weak defect measurement. The results of the paper can provide a certain reference for the optimization and improvement of the surface defect measurement method of ultra-precision curved optical components.