APPROXIMATE DYNAMIC-MODEL FOR EVALUATING DISTORTION IN A SEMICONDUCTOR-LASER UNDER OVERMODULATION

Overmodulation of a directly modulated semiconductor laser causes dist ortion in the optical signal. This distortion can be analyzed, in a fi rst approach, using the model of a static limiter for the laser. In th is letter, the dynamic effects in overmodulation of a semiconductor la ser are addressed for a sinusoidal modulating current and an improved model is proposed by introducing an hysteresis. A time delay is taken into account for evaluating additional dynamic distortion arising when the optical intensity rises above threshold.