Lateral coupling of InP/GaInAsP/InP structures by selective area MOMBE

Abstract

Lateral couplings of InP/GaInAsP/InP structures selectively grown by metalorganic molecular beam epitaxy (MOMBE) are presented. The heterostructures were grown by either using the hydrides AsH3 and PH3 or tertiarybutylphosphine and tertiarybutylarsine as group V precursors in a prototype multiwafer (MOMBE) system. The base heterostructures of the first epitaxy were patterned with SiO 2 mask stripes and trenches were reactive-ion etched. Heterostructures were selectively filled in by a second growth run forming lateral heterojunctions of different quaternary materials. The structures exhibit a bright photoluminescence and a sharp transition at the boundary of the locally grown material indicating a high crystal quality up to the lateral junction with only a minor change in the PL wavelength ( < 2 nm). These optimized lateral couplings were applied to laser/waveguide butt-couplings. Optical coupling losses were determined by means of reactive-ion etched waveguides across cascades of coupled GaInAsP layers with an emission wavelength of λ G 1050 nm. Values as low as 0.12 dB/coupling were determined in cut-back measurements.