Patent ID: 6124931
Filing Date: 2000-09-26
Classification: G01B,G01N

Abstract:
Interferometric apparatus or monitoring select intrinsic optical properties of a gas, said interferometric apparatus comprising:interferometer means comprising a reference leg and a measurement leg, said reference leg being configured and arranged to be occupied by a predetermined medium and said measurement leg being configured and arranged to be occupied by the gas;means for generating at least two light beams having different wavelengths;means for introducing at least a portion of each of said light beams into said interferometer means so that each beam portion travels through said gas along predetermined paths and another portion of at least one of said beams so that said another portion travels through said predetermined medium along predetermined paths, said portions and said another portion of said beams emerging from said interferometer means as exit beams containing information about the respective optical path lengths through said predetermined medium in said reference leg and about the respective optical path lengths through said gas in said measurement leg;means for combining said exit beams to produce mixed optical signals containing information corresponding to the phase differences between each of said exit beams from corresponding ones of said predetermined paths of said reference and measurement legs; andmeans for detecting said mixed optical signals and generating electrical interference signals containing information corresponding to the select intrinsic optical properties of the gas.