title: Absolute distance measurement with an optical feedback interferometer.
abstract: An important use of the self-mixing effect inside a frequency-modulated single-mode laser diode is in laser velocimetry and range-finding applications. The optical beam reflected by a target and injected into the laser diode cavity modulated by a reshaped current is mixed with the light inside the cavity, causing variations of the optical output power. A theoretical analysis of this effect is proposed, based on the determination of the beat frequencies of the optical power variations, to improve the accuracy of laser distance measurement. A resolution of ?1.5 mm from 50 cm to 2 m is obtained when thermal effects are taken into account.
authors.forename: F
authors.initials: F
authors.lastname: Gouaux
authors.forename: N
authors.initials: N
authors.lastname: Servagent
authors.forename: T
authors.initials: T
authors.lastname: Bosch