Near- and far-field observations of transient behavior in pulsed graded barrier quantum well lasers

Abstract
The pulsed behavior of both gain-guided and index-guided graded barrier quantum well lasers has been studied with near- and far-field lateral mode measurements at different pulse widths. Above threshold, gain-guided devices show a transition to predominantly index-guided operation as a result of thermally induced waveguiding. Similar devices with built-in real index guiding exhibit low threshold, stable mode operation, with no observable variations with pulse width.