The Reduction of Semiconductor Laser Phase Noise for Sensor Applications

Abstract

Semiconductor lasers are particularly attractive as sources for optical sensors. However, if they are to be incorporated in unbalanced interferometric sensors their phase noise must be reduced. This paper describes methods by which this may be achieved using (a) passive optical feedback from an array of mirrors or optical fibres, and (b) active control of the laser drive current from the output of an interferometer monitoring the laser emission.