Impact of Pocket Geometry on Quantum Dot Lasers Grown on Silicon Wafers

Epitaxially grown quantum dot (QD) lasers in narrow pockets on patterned silicon photonics wafers present a key step toward full monolithic integration of on-chip light sources. However, InAs QD lasers grown in deep and narrow pockets demonstrate limited performance and reliability compared to planar-grown counterparts. Herein, InAs QD lasers are grown in patterned SiO2 pockets atop planar thermal cyclic annealed GaAs on (001) Si substrate with reduced threading dislocation density, enabling detailed study of how pocket geometry impacts device performance. Fabry-Perot lasers with cleaved facets exhibit strong variation in performance based on the dimensions of the pocket, wherein thermal and optical metrics improve with increasing pocket width. Devices lase up to a maximum stage temperature of 115 degrees C with an extrapolated lifetime of 2.2 years at 80 degrees C for material grown in 50 mu m by 3900 mu m pockets. This study addresses, the ongoing challenge of optimizing pocket-grown devices to planar equivalent performance. Herein, InAs quantum dot lasers are grown in patterned SiO2 pockets atop planar thermal cyclic annealed GaAs on (001) Si substrate with reduced threading dislocation density, enabling detailed study of how pocket geometry impacts device performance. Fabry-Perot lasers with cleaved facets show improved thermal and optical metrics with increasing pocket width.image (c) 2023 WILEY-VCH GmbH