Optical Feedback Stabilization of a Semiconductor Laser

Abstract

The large phase noise and hence broad line width of a GaAlAs semiconductor laser generally precludes the device from being used as a spectral probe of sharp resonance phenomena. Optical feedback lends itself as one possible means by which this broadband noise may be reduced. Experimental data to be presented depict the diode’s sensitivity to weak optical feedback; emphasizing the possibility of inducing either phase noise reduction or enhancement. An autostabilization scheme was presented whereby center frequency stabilization at reduced linewidth can be achieved for an extended period of time.