Auto Adaptive Signal Processing of a Laser Diode Self-Mixing Displacement Sensor

A semiconductor laser subject to optical moderate feedback can be used to design an interferometric displacement sensor. The auto adaptive signal processing presented in this paper has been computed in order to ameliorate the accuracy of such a sensor. This set-up has been successfully tested for both harmonic and aleatory displacements of a remote piezoelectric actuator. Measurements of displacements up to 10 mum has been achieved with an accuracy of plusmn80 nm