Patent ID: 6567588
Filing Date: 2003-05-20
Classification: G02B,G03F

Abstract:
A method for fabricating with a lithography tool a phase mask for a chirped fiber Bragg grating having a plurality of progressively chirped grating segments stitched together comprising the steps of:providing a substrate having a planar surface coated with photoresist; establishing a fixed reference on said substrate; establishing a set of scale factors corresponding to said progressive chirp of said grating segments; calculating a reference scale factor for a hypothetical segment outside of said plurality of progressively chirped grating segments; and calculating a correction factor for each segment using said hypothetical segment as a reference; dividing said substrate into an array of said plurality of grating segments relative to said fixed reference and according to said correction factor whereby each grating segment is stitched to the segments adjacent thereto; exposing said photoresist to an image writing element of said lithography tool according to said array; developing said photoresist; and etching said substrate to produce a phase mask having a plurality of progressively chirped surface relief grating segments.