Design & Optimization of F-Theta Focusing Lens Based on ZEMAX

In this paper, an optical simulation system f-theta lens composed of three ordinary glass spherical lenses is optimized by using optical design software. The lens is made of quartz glass which is commonly used in infrared band. The total length of the lens is 139mm, forming area is 85mm × 85mm. It is compact, simple and low cost. Additionally, the focal spot is very small, and the moving aperture is in a large range of 10-40mm. The focusing performance is close to the diffraction limit, and the spot size of the image plane reaches the diffraction limit of 3μm. The relative linear distortion is less than 0.005%. Therefore, our design meets the requirements of high precision for optical devices.