Thermal rollover characteristics up to 150 degrees C of buried-stripe type980-nm laser diodes with a current injection window delineated by a SiNx layer

In order to improve device robustness of buried-stripe type 980-nm laser di odes against excess current injection even under high temperature operation , we have introduced a current injection window delineated by a SiNx layer to suppress current injection near the facets. The devices showed complete thermal rollover characteristics at temperatures up to 150 degrees C with 8 00-mA continuous-wave current injection while devices without the layer fai led due to front facet degradation during high temperature tests. We think the improvement of device robustness with a SiNx layer is attributable to s uppression of nonradiative recombination of carriers overflowing from the a ctive layers near the facet and to reduced light absorption at the facet br ought about by suppression of carrier-induced bandgap shrinkage.