A method for producing a Bragg grating in an optical waveguide device such as an optical fiber. The optical fiber is exposed to a UV source through a phase mask and this produces a Bragg grating on the fiber. The grating on the fiber is overexposed such that the gratings are stronger than desired. The...http://www.google.com.au/patents/US7336872?utm_source=gb-gplus-sharePatent US7336872 - Localized annealing of UV induced index grating in optical waveguides
