Optical feedback effects in cw injection lasers

A laser diode can simultaneously function as a light source and detector of its own radiation. The addition of a reflecting surface external to the laser produces changes in the laser output power, the current at constant voltage, and the voltage drop across the laser at constant current. The optical feedback reduces the gain necessary to reach the lasing threshold thus increasing the power output at a given dc current level. In this paper we describe the effects of such feedback on the operating characteristics of cw oxide defined stripe AlGaAs lasers.