Process design for micro core mould of binary optical element

Based on the spatial light modulation characteristics of digital micro-mirror device (DMD), a process design method for micro core mould of binary optical element (BOE) is proposed. A computer program was designed to simulate the vectograms of different BOEs such as Fresnel lens, Dammann grating, and Ronchi grating. The BOE pattern displayed on DMD was imaged on the substrate coated with photoresist by 14× reduction optical system, and the BOE mask can be obtained after development, fixation and electrochemical etching. By using DMD system, BOEs were fabricated with low cost and high efficiency, and fabrication parameters could be controlled，which were suitable for many optical systems.