Optical scanning microscopy has been widely used to detect light scattering particles or lattice defects in crystals1'2). On the other hand, optical heterodyne technique using a local heterodyne optical system has been adopted by some authors for aberration free image formation3,4). In this study we developed a light scattering microscope with a differential heterodyne optical system simplified in its configuration by the use of a Zeeman laser, and the feasibility of the system was examined experimentally. Differential heterodyne optical system has the advantage of gaining strong scattered light, simple congiguration, and applicability to the detection of other kinds of physical quantities such as acoustic waves and optically induced electric currents.
"Differential Heterodyne Optical Probe Using A Zeeman-Laser", Proc. SPIE 0813, Optics and the Information Age, (1 January 1987); doi: 10.1117/12.967269; https://doi.org/10.1117/12.967269