Imaging Simulation And Image Quality Evaluation Of Optical System With Inhomogeneous Medium

Inhomogeneity of optical medium in high-precision optical system often influences the system’s imaging quality. Along with the optical technology’s progress and growing demand for higher imaging quality, Inhomogeneity of optical medium has become an important factor that refer to the optical system’s performance. The optical system used in the field of optical measurement, semiconductor microlithography and aerial mapping, often has the problem of inhomogeneity, so studying the inhomogeneous medium is meaningful to improve the system’s performance.The methods of Polynomial-fitting and Finite-element can be used to describe the refractive index distribution of inhomogeneous medium. By using the method of ray optics to simulate ray tracing in inhomogeneous medium, the Modulation transfer function and wave aberration of optical system can be calculated.In actual optical system, the lenses manufactured by different parts of a same semi-finished optical glass have different influence to imaging quality. In the process of assembling, rotating the lens around the optical axis brings changes in imaging quality. In order to improve optical system’s performance, the method of damped least square can be used for optimization.