Void engineering in epitaxially regrown GaAs-based photonic crystal surface emitting lasers by grating profile design

We report the engineering of air voids embedded in GaAs-based photonic crystal surface-emitting lasers realized by metalorganic vapor-phase epitaxy regrowth. Two distinct void geometries are obtained by modifying the photonic crystal grating profile within the reactor prior to regrowth. The mechanism of void formation is inferred from scanning transmission electron microscopy analysis, with the evolution of the growth front illustrated though the use of an AlAs/GaAs superlattice structure. Competition between rapid lateral growth of the (100) surface and slow diffusion across higher index planes is exploited in order to increase the void volume, leading to an order of magnitude reduction in threshold current and an increase in output power through an increase in the associated grating coupling strength.

Automated summary

By using metalorganic vapor-phase epitaxy regrowth, air voids embedded in GaAs-based photonic crystal surface-emitting lasers have been engineered with two different geometries achieved by modifying the photonic crystal grating profile within the reactor prior to regrowth. The mechanism of void formation was inferred through scanning transmission electron microscopy analysis, utilizing the competition between rapid lateral growth of the (100) surface and slow diffusion across higher index planes to increase void volume. This led to a tenfold reduction in threshold current and an increase in output power by strengthening grating coupling.