Fundamental Theory of Semiconductor Lasers and SOAs

Abstract

This chapter aims to give a basic understanding of semiconductor lasers and semiconductor optical amplifiers (SOAs). Starting from the underlying physics of radiative emission, together with the elements of optical waveguide theory, simple approximations are found for optical gain, lasing threshold and cavity resonances. Rate equations are used to elucidate time-dependent laser behaviour and, in combination with a travelling-wave equation for spatial photon distribution, to describe the effects of saturation and crosstalk in SOAs.