Optical Feedback Semiconductor Laser Michelson Interferometry of weakly-reflecting samples

Abstract

Optical interferometry allows us to perform non-invasive distance measurements at diffraction-limited resolution, which is a distinct advantage in metrology and instrumentation. However, most available interferometric techniques do not have the capability to resolve the direction of motion of the reflecting sample along the direction of the probe optical beam. In 2001 Rodrigo et al. developed the Optical Feedback Semiconductor Laser Michelson Interferometer (OSMI) which provides submicron axial displacement measurements with directional information. In this paper we use numerical simulations to analyze the behavior of the OSMI interferogram for weakly reflecting sample and reference mirrors. Our results show that the directional information of the OSMI is lost for sample or reference mirrors with very weak reflectivity.