Patent ID: 7009708

Claim:
In an interferometer device configured for a common path heterodyne mode of operation, an optical component comprising: a first arrangement of reflective surfaces configured to receive a source beam and to produce therefrom a measurement beam and a reference beam, said measurement beam being directed to a target along a first propagation path, said reference beam being directed along a second propagation path; and a second arrangement of reflective surfaces configured to receive as a return beam said measurement beam reflected from said target and to direct said return beam along a portion of said second propagation path to reassemble said return beam and said reference beam, said first arrangement of reflective surfaces comprising at least a first surface in substantially parallel relation to at least a second surface and spaced apart therefrom by a distance D, said second arrangement of reflective surfaces comprising at least a third surface in substantially parallel relation to at least a fourth surface and spaced apart therefrom by a distance substantially equal to D, said first arrangement of reflective surfaces being in substantially parallel relation to said second arrangement of reflective surfaces.