Liquid-Crystal Phase-Shifting Shearing Interferometer

The liquid-crystal phase-shifting shearing interferometer is a common-path interferometer based partly on a lateral-shear-plate interferometer. It bears a partial similarity to the liquid-crystal point-diffraction interferometer (LCPDI), which is also of the common-path type. The phase-shifting nature of this interferometer is expected to increase (relative to prior shearing interferometers) resolution by up to two orders of magnitude. The liquid-crystal phase-shifting shearing interferometer is expected to be useful for measuring spatially varying optical density in a laboratory or manufacturing setting; examples of such densities include the index of refraction of a liquid in a production process, the density and/or temperature of a gas in a combustion system, and the temperature of a fluid in a boiler.