Fabrication of 1×4 MMI Coupler with DMD System Based on Holography

This article presents a new method to make MMI coupler on the Silver Halide Film with Digital Micro mirror Device (DMD) system, without using special mask plate. It uses the refractive index modulation capacity of Silver Halide Film by controlling the exposure to make different refractive indexes thereby forms the core and cover. It does not need further etching and just one exposure, which provides a fast and low-cost method to make holographic micro-optical components.