Theory and experiments of single-mode ridge waveguide GaAs–AlGaAs semiconductor ring lasers are presented. The lasers are found to operate bidirectionally up to twice the threshold, where unidirectional operation starts. Bidirectional operation reveals that just above threshold, the lasers operate in a regime where the two counterpropagating modes are continuous wave. As the injected current is...

Synchronization of fast chaotic oscillations of the order of gigahertz is experimentally observed in two external-cavity semiconductor lasers.

Sub-carrier-multiplexed (SCM) fiber optic systems have received much attention for local access networks, fiber radios, and cable television distributions [l]. With SCM, multiple channels of analog videos and digital telephony/data can all be simultaneously transmitted by a single optical carrier and detected by the same photodetector. Direct modulation of semiconductor lasers is a simple, low-...