Patent ID: 7557930
Filing Date: 2009-07-07
Classification: G01B

Abstract:
1. An optical interferometer comprising: an optical source that generates an at least partially coherent optical source beam having a wavelength; means for generating diffracting, sensing light beam component and a diffracting, reference light beam component, that propagate over a sensing beam optical path and a reference beam optical path, respectively, from the source beam, wherein the sensing beam optical path includes a free-space optical path medium that traverses sensing beam phase-disruptive measurement environment; means for phase modulation of at least one of the light beam components; a detector positioned to detect an interference pattern produced by the interference between a non-diffracting, sensing light beam, component and the reference light beam components; a demodulator disposed in a detection path of the interferometer; and a non-diffracting light beam generator disposed to intercept the diffracting, sensing light beam component, wherein an output of the non-diffracting light beam generator is the non-diffracting, sensing light beam component that propagates through the phase-disruptive measurement environment.