A Fast Optical Design Method for the Objective Under Köhler Illumination to Reduce Ghost Images

Abstract In high-precision microscopy, Köhler illumination is often used to ensure clear surface details. However, it can introduce artifacts, such as ghost images, which must be effectively controlled. Here, we propose a matrix optics method (MOM) to estimate the ghost images formed in the microscope objective under Köhler illumination. On the basis of MOM, we develop a function for the evaluation of image quality and ghost image intensity. Using this function, we can optimize the objective to mitigate the ghost images and preserve a good image quality simultaneously. The research results show that our method can reduce the intensity of ghost image by 60.6% as well as the time consumption from 158 seconds to 3 seconds for each iteration. This method can be potentially useful for the optical design of microscope objective.