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

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