The multi-mode rate equations for semiconductor lasers with thermal effects

Abstract

A simple mathematical model describing coupled electrical, optical and thermal effects in semiconductor lasers is introduced. The bifurcation structure of the underlying (perfect) isothermal equations is examined to acquire insight into the nature of the steady states. An infinite set of steady states is obtained at one of these bifurcation points. In the (imperfect) isothermal and thermal problems, an asymptotic analysis provides expressions for the parameter regions which characterise the stable steady states of single-mode operation. The reason that semiconductor lasers usually operate with a single dominant mode is that this corresponds to the only stable steady state. Parameter regions in which two modes share dominance are also identified.