Patent ID: 7871760
Filing Date: 2011-01-18
Classification: G02B,G03F

Abstract:
1. A method of fabricating a turning mirror for an optical device, comprising the steps of: depositing on a substrate, which defines a plane in which an optical signal propagates in a propagating direction, a photoresist layer sensitive to electrons and to UV radiation, the material in which said photoresist layer is formed having a contrast not larger than 3; exposing a first portion of said photoresist layer to an electron beam, wherein the electron dose of said electron beam exposure is varied within said first portion according to a selected pattern, and wherein the electron dose to which a given region in the photoresist is exposed depends on the resulting photoresist height in said given region after development; exposing a second portion of said photoresist layer to UV radiation, said first and said second portion being overlapped at least in a third portion; developing said photoresist layer so as to form in said third portion of said photoresist layer exposed to both electron beam and to UV radiation a first surface having an angle relative to the propagating direction; and etching said substrate and said photoresist so that a second angled surface is formed in said substrate in correspondence to said third portion, said second surface forming an angle with said propagating direction.