Circular-polarization-splitting common-path interferometer based on a zero-twist liquid-crystal display

We present a compact optical circular-polarization-splitting common-path interferometer based on a zero-twist liquid-crystal display (LCD). A blazed diffraction grating is encoded onto the LCD. The optical system produces a reference beam that has one sense of circularly polarized light, while the diffracted beam has the opposite sense of circularly polarized light. Using a linear polarizer, these two beams form an interferogram that can be used to analyze optically active media. Experimental results are provided showing the detection of left-handed-rotary and right-handed-rotary media.