Homodyne optical sensor system incorporating a multi-phase beam combining system

A homodyne interferometer comprising:

• an optical beam guidance system configured to output a composite beam that includes a first reflected light component having a first polarization and a second reflected light component having a second polarization;
• and
• a multi-phase beam combining system comprising:
• a diffraction grating arranged to receive the composite beam from the optical beam guidance system and to produce therefrom, a diffracted plurality of light beam members;
• a multifaceted birefringent optical element arranged to receive the diffracted plurality of light beam members from the diffraction grating and to propagate each of the diffracted plurality of light beam members over a respective optical path through the multifaceted birefringent optical element, each of the diffracted plurality of light beam members having the first polarization undergoing a differential phase shift with respect to each of the diffracted plurality of light beam members having the second polarization, the differential phase shift based at least in part on an angular inclination of at least one major external surface of the multifaceted birefringent optical element with respect to a light-propagation axis of the multi-phase beam combining system, wherein the at least one major external surface is a sloping planar surface of the multifaceted optical element, the sloping planar surface having a slope angle that defines the angular inclination with respect to the light-propagation axis of the multi-phase beam combining system;
• a polarizer arranged to receive the diffracted plurality of light beam members after propagation through the birefringent optical element and to provide an interferometric effect that is indicative of in-phase and out-of-phase relationships in the diffracted plurality of light beam members;
• and
• a focusing lens arranged to receive the diffracted plurality of light beam members after propagation through the polarizer and to at least direct a first subset of light beams towards a first focal point and a second subset of light beams towards a second focal point.

A homodyne interferometer comprising:

• an optical beam guidance system configured to:
• receive a coherent beam of light;
• split the coherent beam of light into a first light component having a first polarization and a second light component having a second polarization;
• direct the first light component towards a reference object;
• direct the second light component towards a target object;
• receive from the reference object, a first reflected light component having the first polarization;
• receive from the target object, a second reflected light component having the second polarization;
• and
• output a composite beam that includes the first reflected light component having the first polarization and the second reflected light component having the second polarization;
• and
• a multi-phase beam combining system comprising:
• a diffraction grating arranged to receive the composite beam from the optical beam guidance system and to produce therefrom, a diffracted plurality of light beam members;
• a birefringent optical element arranged to receive the diffracted plurality of light beam members from the diffraction grating and to propagate each of the diffracted plurality of light beam members over a respective optical path through the birefringent optical element, each of the diffracted plurality of light beam members having the first polarization undergoing a differential phase shift with respect to each of the diffracted plurality of light beam members having the second polarization, the differential phase shift based at least in part on an angular inclination of at least one major external surface of the birefringent optical element with respect to a light-propagation axis of the multi-phase beam combining system, wherein the at least one external major surface has a non-planar surface contour;
• a polarizer arranged to receive the diffracted plurality of light beam members after propagation through the birefringent optical element and to provide an interferometric effect that is indicative of in-phase and out-of-phase relationships in the diffracted plurality of light beam members;
• and
• a focusing lens arranged to receive the diffracted plurality of light beam members after propagation through the polarizer and to at least direct a first subset of light beams towards a first focal point and a second subset of light beams towards a second focal point.