Patent ID: 6597462
Filing Date: 2003-07-22
Classification: G01J,H01S

Abstract:
A method for determining a relative wavelength shift of a laser beam at an operating wavelength away from a known first reference line using a Fabry-Perot monitor etalon, comprising the steps of:measuring data of wavelength deviations between at least one known additional reference line relative to the first reference line and a measured shift of the beam at the operating wavelength from the first reference line using the Fabry-Perot monitor etalon; determining an etalon constant based on a fit to the data, and thus a wavelength shift dependence of the FSR of the etalon; and measuring and calculating a wavelength shift from one of the known reference lines of the beam at the operating wavelength using the etalon and the FSR calculated using the etalon constant determined in the determining step.