Optical-feedback-induced stability and instability in broad-area semiconductor lasers

Stable and unstable oscillations of broad-area semiconductor laser with optical feedback are experimentally examined. We observe stable oscillations and also coexistent states between stable oscillations and low-frequency fluctuations depending on the feedback positions of the laser beam in the active layer. The laser shows single mode operations both for the oscillation frequency and the spatial mode when it is stabilized. (c) 2005 American Institute of Physics.