Abstract

Multistripe gain-guided diode lasers were developed to overcome filamentation problems which occur in conventional broad-area lasers. However, the use of quantum-well active regions in broad-area devices greatly reduces the tendency toward filamentation.¹ With filamentation removed, the behavior of broad-area devices can be examined in an attempt to understand and better control the operation of these devices. While uniform near-field intensity profiles have been reported for short-pulse (≤500-ns) operation,^2,3 multipeaked (multilateral transverse mode) behavior is observed for long-pulse and cw operation. We have modeled a 100-µm wide broad-area device operating cw near threshold and have compared the calculated eigenmodes with those observed in similar free-running devices. For long-pulse and cw operation, the presence of a real refractive-index profile across the broad active layer due to heating effects is shown to be important in determining the dominant lasing mode. We also present the results of injection seeding studies which allow us to selectively induce oscillation in a number of lower-gain modes which would otherwise not be observable.

© 1986 Optical Society of America