Patent ID: 6601411
Filing Date: 2003-08-05
Classification: C03B

Abstract:
A method for annealing an optical waveguide having along some lengths an induced refractive index difference that decays over time and so causes drift in the wavelength of reflected light when light is inserted into the optical waveguide, the method using a decay formula for the induced refractive index difference indicating how the induced refractive index difference decays over time, the assumed decay formula having parameters that depend on temperature, the method comprising the steps of:a) determining the parameters in the decay formula for both an operating temperature and an annealing temperature, the annealing temperature being higher than the operating temperature, by fitting an observed decay over a measuring time at the operating temperature and at the annealing temperature; and b) determining an anneal time at the annealing temperature based on a maximum allowed drift of the wavelength of reflected light when the optical waveguide is held at a temperature of no more than the operating temperature.