Optical bistable-switching operation in semiconductor lasers with inhomogeneous excitation

Bistable operation is examined in the paper for DH semiconductor lasers employing inhomogeneous excitation. Steady-state rate equations are analysed in terms of typical parameters for contemporary stripe-geometry lasers, and it is shown that the I/L curves demonstrate bistability. Characteristics for optical bistable-switching operations effected by trigger current pulses are also numerically analysed through the use of nonlinear rate equations. Bistable operation has been achieved experimentally with InGaAsP/InP DH lasers through a newly designed periodic excitation stripe geometry. Bistability was observed within a current range less than 10° of the threshold current. The range was seen to strongly depend on the stripe geometry anddevice temperature, which are controllable. Switching between the two stable states was accomplished by application of an electrical pulse. Switching time was about 1 ns.