Patent ID: 9574868
Date: 2017-02-21
CPC Classifications: G01B,G02B

Claim:
1. An interferometric device comprising a light directing optical arrangement for directing light to an optical detector, wherein the light directing optical arrangement is configured for defining first and second substantially overlapping optical paths towards said optical detector, the light directing optical arrangement comprising: a beam splitter/combiner unit for receiving an input beam having an amplitude and phase modulation and splitting said input beam into first and second light beams; first and second reflective surfaces accommodated in the first and second optical paths of said first and second light beams to direct said first and second light beams back to said beam splitter/combiner that directs the combined beam to the detector, wherein one of said first and second reflective surfaces comprises a retro-reflector configured and operable to reflect said first light beam and shift a Fourier plane center of the reflected light beam, so that an off-axis angle is created between said first and second light beams, wherein said retro-reflector is positioned in the Fourier plane of the reflected light beam; and a spatial filter comprising a pinhole accommodated in front of one of the first and second reflective surfaces and a Fourier optics assembly comprising two lenses, one lens being in a 4f configuration with respect to the other; wherein the beam splitter/combiner unit directs one of the first and second light beams through said spatial filter to enable amplitude and phase demodulation thereof and formation of a reference beam with respect to the other modulated beam.