Patent ID: 7423759
Filing Date: 2008-09-09
Classification: G01J

Abstract:
1. A wavelength determining apparatus comprising: a reference wavelength measurer that measures a wavelength of second reference wavelength light based upon a number of interference fringes generated by an optical path difference of first reference wavelength light, and a number of interference fringes generated by the optical path difference of the second reference wavelength light; an input light wavelength measurer that measures a wavelength of input light based upon the number of interference fringes generated by the optical path difference of the first reference wavelength light, and a number of interference fringes generated by the optical path difference of the input light; a correction coefficient determiner that determines a correction coefficient based upon the measured wavelength of the second reference wavelength light and the measured wavelength of the input light; and an input light wavelength corrector that corrects the measured wavelength of the input light by multiplying the measured wavelength of the input light by the correction coefficient.