Design of diffractive optical element for ultra-thin deep ultraviolet imaging system

Optical imaging systems operating in the deep ultraviolet (UV) waveband have many applications in nanofabrication, medical and cellular imaging. However, Current deep UV optical systems are large form factors and complications since they usually base on the refractive lens and the limitation of available materials in deep UV waveband. The main reason is that chromatic and thermal aberration of the refractive lens is challenging to correct under limited available materials. In this paper, we proposed to use a single diffractive optical element (DOE) to construct a lightweight and ultra-thin UV imaging system. The achromatic realize base on the end-to-end design of the DOE and the following image processing algorithm. The athermalization achieves due to the inherent small thermal aberration of DOE. We design a DOE with a focal length of 50 mm, F-number of 4, and effective thickness of only 1μm for deep UV application. Simulation results show it realized excellent deep UV imaging performance over the waveband of 240 nm ~ 280 nm and working temperature range of - 40 °C ~ + 80 °C.