Abstract:

Once an object is placed in the beam of a laser diode, a part of the beam reflected by the latter is retro-injected in the active cavity of the diode and disrupts the physical properties of it. This disruption which is shown principally by a modification of the frequency of the emission power of the diode is known as the phenomenon of “self-mixing” Long considered as a parasitic phenomenon, notably in telecommunication by optical fibres, we will present its exploitation for metrological ends, such as the measurement of speed, of displacements, and of distances.

Keywords:

Optical retro-injection, Self-mixing, laser diode, Displacement measurement, Speed measurement, Distance measurement,