Fabricating optical waveguide gratings

摘要

A method of fabricating an optical waveguide grating having a plurality of grating lines of refractive index variation comprises the steps of: (i) repeatedly exposing a spatially periodic writing light pattern onto a photosensitive optical waveguide: and (ii) moving the writing light pattern and/or the waveguide between successive exposures of the writing light pattern, so that each of at least a majority of the grating lines is generated by at least two exposures to different respective regions of the writing light pattern.