Low-magnification polarization phase-shifting interference microscope for three-dimensional profilometry

Abstract

An interferometric technique for three-dimensional phase measurement of optically transparent microscopic phase samples is presented. An obliquely aligned polarizer-masked cube beam-splitter, an infinity-corrected microscope objective, and a couple of simple polarization phase-shifting components serve as the setup for such a measurement. Surface phase profiles are then extracted using standard phase-shifting algorithms. The salient features of the proposed technique are its simple design, in-line configuration, possibility of integration with standard microscopic systems, and inherent compensation of the substrate phase. Experimental results are presented. The overall lateral magnification is restricted due to the low numerical aperture offered by the microscope objective and cube beam-splitter combination.