Magnetically programmable bistable laser diode with ferromagnetic layer

A new design of bistable laser diode, which consists of a gain section, absorption section, and nonreciprocal section, is proposed. The nonreciprocal section is made of a semiconductor optical amplifier covered by a ferromagnetic layer. The nonreciprocity of magneto-optical effect significantly modifies a photon density distribution in the laser cavity and enlarges a width of hysteresis loop of bistable laser diode. The bistability can be switched on or off by reversing magnetization of the ferromagnetic layer.