Provided is an optical waveguide with an inscribed Bragg grating, where the Bragg grating is stable at high temperature, has low scattering loss and high reflectivity. Also provided is a method for inscribing a Bragg grating in an optical waveguide, the method comprising irradiating the optical waveguide with electromagnetic radiation from an ultrashort pulse duration laser of sufficient intensity to cause a permanent change in an index of refraction within a core of the optical waveguide, where the irradiating step is terminated prior to erasure of a Bragg resonance, and heating the optical waveguide to a temperature and for a duration sufficient to substantially remove a non-permanent grating formed in the optical waveguide by the irradiating step.