A model of a diode laser actively mode-locked by gain modulation

Abstract

A rate-equation analysis of a diode laser in an external resonator which is actively mode-locked by periodic modulation of the injection current is presented. A computer simulation of the transient process of pulse generation is developed. The coupled rate equations for electron and photon densities as functions of time and position within the diode are solved numerically. The effects of sinusoidal and pulsed injection current, spatial and temporal gain saturation, various resonator configurations, mismatch between modulation frequency and round-trip frequency, and varying laser parameter values are considered. A comparison of results with those of previous theories is presented. Optimum conditions for mode-locking are stated.