Demonstration of optical bistability with intensity-coupled high gain lasers

Competition between external beam amplification and normal laser action is shown to result in a new type of optical bistability in high gain lasers. With one dye laser in a delayed self-extinction configuration, periodic pulsations are observed, showing the alternation of two quasi-stable states. With a twin dye laser configuration, only one laser at a time could be above threshold due to their mutual coupling. Switching with subnanosecond rise time has been obtained in a purely optical way.