Laser Self-Mixing Interferometer Based on Multiple Reflections and Phase-Modulation Technique

New absolute distance measurement technique with a self-mixing interferometer

A new compact self-aligned noncontact range finder is described. It uses the selfmixing effect inside a laser diode. Double modulation technique is proposed to improve the measurement accuracy. Wavelength modulation (WM) of the laser beam is obtained by modulating the injection current of the laser diode. Phase modulation (PM) of the laser beam is obtained by an electro-optic crystal (EOC) in t...

Self-mixing Interferometer for Contactless Vibration Measurements

Self-mixing interferometer is a suitable tool for implementing industrial sensors, with the advantages of optical techniques, such as high accuracy and contactless operation, but at potential very-low cost. This paper describes some techniques recently developed for realizing vibration measurements, based on different signal elaborations and with different performances and applications. Particu...

Phase noise of diode laser in self-mixing interference.

We investigate the phase noise of a diode laser based on the interferometric self-mixing effect. A detuned Fabry-Perot cavity converts the phase noise into intensity noise, and the noise is measured by the novel method as a function of the amount of feedback and the distance between the target and the laser front facet. Experimental results can be well explained by theory.

Piezoelectric Actuated Phase Shifter Based on External Laser Interferometer: Design, Control and Experimental Validation

To improve the phase-shifting accuracy, this paper presents a novel integrated framework for design, control and experimental validation of the piezoelectric actuated phase shifter with a trade-off between accuracy and cost. The piezoelectric actuators with built-in sensors are adopted to drive the double parallel four-bar linkage flexure hinge-based mechanisms. Three mechanisms form the tripod...

Cross Phase Modulation and Four - Wave Mixing