Research on digital mask fabrication technique of micro-optical element

摘要

By means of control flexibility of digital micromirrors, a digital mask fabrication system of a micro-optical element is designed. A single optical element can be obtained on the substrate after a one-time planar exposure. By using a computer to control the digital micromirrors, real-time movement and switch of the mask can be realized, and accordingly superimposed exposure of the multi-mask can be achieved. The real-time digital-mask technique, the digital-mask-movement technique and the digital-mask-fractal technique are, respectively, investigated. Theoretical analysis and experimental results show that the lost efficiency caused by the limitation of lens aperture is greatly reduced by use of the mask fractal technique. Moreover, the lithography resolution of the gray-scale mask fabricated by an electro-addressable spatial light modulator is improved and the edge acutance is perfected.