Semiconductor laser optical feedback Mach-Zehnder interferometer

Abstract

We model the operational dynamics of a semiconductor laser source under optical feedback in a modified Mach-Zehnder interferometer (OFMZ) and compare its performance with the OF semiconductor laser Michelson interferometer with respect to minute variations in sample reflectivity, refractive index and relative displacement. We show that the OFMZ interferogram is of higher contrast for the same sample reflectivity and its asymmetric profile could indicate the displacement direction of the sample. The OFMZ interferogram offers wider dynamic range and greater resolving power for the same set of optical path length variations.