Influence of current spreading on the transparency current density of quantum-well lasers

Abstract

We investigate the dependence of the threshold current of broad-area lasers on the stripe width. A comparison of differently deep-etched devices fabricated from the same wafer reveals that the stripe width dependence of the threshold current is caused by the current spreading effect. We propose a simple method to obtain a transparency current density characterizing a particular epitaxial structure without being influenced by current spreading.