Liquid-crystal point-diffraction interferometer

Abstract

A new point-diffraction interferometer has been developed with a liquid-crystal filter that permits arbitrary phase shifts to be introduced between the object and reference beams. A microsphere embedded within the liquid-crystal layer provides a locally generated reference beam. We phase shift the object beam by varying a voltage across the liquid crystals, thereby altering the refractive index of the birefringent nematic liquid crystals.