Abstract

In continuous wave (CW) semiconductor lasers, a small amount of backscattered light coupled back into the cavity induces a change in the laser threshold condition and in its carrier density, and consequently induces a modulation in the laser output (AM) and the laser frequency (FM) [1]. This phenomenon, known as self-mixing interferometry (SMI), has been successfully applied as a simple, robust and self-aligned technique for distance, displacement, velocity and remote vibration detection [2]. Despite its wide applicability, usually based on AM signal detection, SMI is limited to distances up to few meters for diffuse targets.

© 2015 IEEE