1/f noise in semiconductor heterostructure laser diodes

Abstract

A new model for electrical low frequency noise in semiconductor heterostructure laser diodes is developed based on number fluctuation theory. The model includes carrier number fluctuation mechanisms such as thermal activation, tunneling and random walk involving bulk traps and interface traps at the heterojunction interface. Noise sources in heterostructure semiconductor laser diodes can be divided into three parts, namely, series resistance including ohmic contacts, p-n junction and the heterojunction. The traps located at the interface and or at the bulk of the barrier layer can induce the modulation of barrier height which in turn results in the current fluctuation. Noise generation mechanisms for p-n junction is reviewed. Correlation between electrical and optical noise is also discussed.