Analysis of a proposed bistable injection laser

The operation of a proposed bistable injection laser is analysed. The device consists of a Fabry-Pérot injection laser whose plated p-contact is divided into two electrically isolated portions by a slit parallel to the light reflecting sides of the crystal. An injection current is passed through one contact. The other is biased so that a negligible injection current flows through the junction beneath it, which then acts as a nonlinear absorber of light. Under proper conditions, the laser will have two states: in one, it emits coherent light and in the other, only spontaneous light, both being stable for the same injection current. Switching between states is possible with electrical pulses or incident light. The analysis is done for liquid helium temperatures and for the recombining electrons lying in an exponential conduction band tail, and for liquid nitrogen temperature and parabolic valence and conduction bands. In both cases, the analysis predicts bistable operation for certain conditions and favors a ratio of absorbing contact length to emitting contact length greater than unity. © 1964.