Bistable lasing in twin microdisk photonic molecules

We demonstrate the bistable lasing in a photonic molecule consisting of twin microdisks. When the photonic molecule was nonuniformly photopumped, the bistability and/or mode switching were observed with an effective pump power of < 100 mu W. The rate equation analysis indicated that the operation was based on saturable absorption and gain switching, which depended on the nonuniformity, disk diameter detuning, and Q factors of coupled modes. Such a bistable laser, particularly showing the mode switching, will be applied for ultrasmall high-speed optical memories, flip-flops, and so on. (C) 2005 American Institute of Physics.