Patent ID: 6462827
Filing Date: 2002-10-08
Classification: G01J

Abstract:
Wavemeter for measuring an unknown wavelength of an optical beam, comprising:a reference beam of a known wavelength having two orthogonally circularly polarization directions; a polarizing beam splitter receiving said orthogonally polarized reference beam and defining an interferometer with a difference in an optical path length between said two orthogonally circularly polarized directions; a first analyzer receiving from the polarizing beam splitter a combined reference beam with said path length difference, said first analyzer determining the path length difference from an intensity measurement of said two orthogonally circularly polarization directions of said combined reference beam; a polarizer converting the optical beam of the unknown wavelength into two orthogonally circularly polarized beams, with the two orthogonally circularly polarized beams of the unknown wavelength traversing in the polarizing beam splitter an optical path that is substantially identical to an optical path of the reference beam in the polarizing beam splitter, and a second analyzer that receives from the polarizing beam splitter a combined beam of the unknown wavelength with said path length difference, said second analyzer determining the unknown wavelength from an intensity measurement of said two orthogonally circularly polarization directions of said combined beam of the unknown wavelength and said path length difference determined by the reference beam.