FAST FABRICATION OF POLYMER OUT-OF-PLANE OPTICAL COUPLER BY GRAY-SCALE LITHOGRAPHY

摘要

A lithographic method for making an out-of-plane optical coupler includes forming a photoresist layer of positive photoresist material over a substrate. The positive photoresist layer undergoes a flood exposure to light through a binary mask to pattern a latent image of a mirror blank in the photoresist layer. A laser beam is scanned over the latent image of the mirror blank to apply controlled dosages of light at specified locations to form a latent image of a planar mirror surface that is oriented at a prescribed non-zero angle to a plane in which the substrate extends. The positive photoresist material is developed so that a remaining portion of the developed positive photoresist material forms an out-of-plane optical coupler having a planar mirror surface that is oriented at the prescribed angle.