Patent ID: 7161683

Claim:
A spectrally dispersive interferometric optical apparatus, comprising a light source, an aperture through which a collimated, monochromatic light beam from the light source passes, a non-polarizing beam splitter upon which the light beam is incident after passing through the aperture and splitting the beam into branches of said apparatus, a mirror situated at an end of one of said branches to reflect the beam back to said non-polarizing beam splitter, a linear actuator arranged to displace said mirror along an optical axis towards and away from said non-polarizing beam splitter, a diffraction grating situated at an end of another of said branches such that the beam diffracted by said grating is directed back to said non-polarizing beam splitter, said non-polarizing beam splitter arranged to superimpose the respective beams, a polarizing beam splitter arranged to receive the superimposed beams from said non-polarizing beam splitter and split the same into separate TE and TM components, and a pair of photodetectors separately arranged to receive a respective one of the separate TE and TM components.