The Expansion of Field of View of Wavefront Coding-based Infrared Imaging System

When the field of view (FOV) increases, a lot of aberrations will be introduced into the optical system, which results in blurred images. Hence, to expand the FOV of the optical system, it is of great significance to suppress the field aberrations. As a classic computational imaging technique, the wavefront coding (WFC) can effectively reduce the sensitivity of the optical system to defocus. In this paper, we introduce WFC into traditional optical design strategies to expand the FOV of an infrared optical system from ±8° to ±14°. The effect of FOV extension to the imaging performance of optical systems is simulated by CODEV. Then, a cubic phase mask is inserted into the stop position of the system to suppress the effect of field aberration. Modulation transfer function, point spread function and image simulation are used to study the feasibility of this method to correct field aberrations. The results show that the WFC system is insensitive to field aberrations, and a clear image can be obtained after digital filtering. The WFC technology can effectively expand the FOV of optical systems.