Absolute distance and velocity measurements by the FMCW technique and self-mixing interference effect inside a single-mode Nd:YAG- microchip laser

In this paper, a theoretical analysis of a sensor which uses a self-mixing interference effect inside a microchip laser is reported. Experimentally, the FMCW approach has been implemented by using both a Nd:YAG microchip laser emitting at and an intracavity crystal. By using the Pockel effect a total 10 GHz shift of the optical wave has been obtained by applying a transverse electrical field inside the crystal. We demonstrated that the dynamics of the microchip laser can be used to perform highly sensitive preamplified detection for absolute distance and velocity measurements from 1 to and from 0.1 to , respectively.