Patent ID: 8272236
Filing Date: 2012-09-25
Classification: G02B

Abstract:
1. A method of producing a thermally stable grating comprising the sequential steps of: a) providing an optical waveguide having a type II characteristic intensity threshold for type II grating formation; b) lowering the type II characteristic intensity threshold for type II grating formation of the waveguide by at least 25%; and, c) irradiating the waveguide with femtosecond pulses of light having a sufficient intensity and for a sufficient duration to write the grating having a peak refractive index change Δn so that at least 60% of the peak refractive index change Δn of the grating remains after exposures of at least 10 hours at a temperature of at least 1000° C., wherein the sufficient intensity is less than the type II characteristic intensity threshold for type II grating formation of the optical waveguide; d) wherein the step of lowering the characteristic intensity threshold comprises the step of providing the optical waveguide such that the waveguide is hydrogen or deuterium loaded.