Patent ID: 7352931
Filing Date: 2008-04-01
Classification: G02B

Abstract:
1. A method for manufacturing a multi-channel optical grating in a photosensitive medium, each channel of said multi-channel grating having an individual spectral response, said method comprising the steps of: a) for each channel, individually designing an index profile of a sub-grating providing the corresponding individual spectral response, each of said index profiles comprising an individual apodization profile and an individual phase profile of the corresponding sub-grating; b) determining a target index profile Δn where z is an optical axis of said multi-channel grating, k is an indicia representing said sub-gratings, Δn c) determining a modified index profile having a smooth apodization profile and providing said target spectral response at least within a spectral region of interest; d) encoding a phase mask according to said modified index profile; and e) photoinducing said multi-channel grating in the photosensitive medium using said phase mask.