Displacement Measurements Using a Self-Mixing Laser Diode Under Moderate Feedback

Abstract

A semiconductor laser subject to moderate optical feedback has been used to design an interferometric displacement sensor. The autoadaptative signal processing presented in this paper has been computed in order to improve the accuracy of such a sensor. This setup has been successfully tested for both harmonic and aleatory displacements of a remote piezoelectric actuator with a maximum accuracy of 40 nm