Bistability in coupled cavity semiconductor lasers

Experimental results on bistable operation of coupled cavity semiconductor lasers are presented. The light level at the upper and lower states can be controlled by varying the injection current. A model calculation of the coupled cavity laser system shows that the bistability is due to nonlinearities associated with above threshold gain saturation. Our results show that a coupled cavity laser can exhibit bistability at all temperatures and, in addition, the size of the ‘‘hysteresis loop’’ can be easily controlled by varying the injection current. These results are significant for a practical bistable optical device.