Photoresist microparabolas for beam steering

Abstract

A simple grating mask has been used in an ordinary 5:1 projection stepper equipment to fabricate microscopic parabolic topographies in thick positive photoresist. The microparabolic surfaces created were coated with reflective material to form parabolic reflectors. Measurement values of focal length were in agreement with the expected theoretical values. The simple parabola forms the basis for the fabrication of compound parabolic reflector which can be used for beam steering. Normal incidence beam can be redirected by the compound parabolic reflector onto device areas in the vicinity of the focus.