LATERAL COUPLING OF INP GAINASP/INP STRUCTURES BY SELECTIVE-AREA MOMBE/

Lateral couplings of InP/GaInAsP/InP structures selectively grown by m etalorganic molecular beam epitaxy (MOMBE) are presented. The heterost ructures were grown by either using the hydrides AsH3 and PH3 or terti arybutyl-phosphine and tertiarybutylarsine as group V precursors in a prototype multiwafer (MOMBE system. The base heterostructures of the f irst epitaxy were patterned with SiO2 mask stripes and trenches were r eactive-ion etched. Heterostructures were selectively filled in by a s econd growth run forming lateral heterojunctions of different quaterna ry materials. The structures exhibit a bright photoluminescence and a sharp transition at the boundary of the locally grown material indicat ing a high crystal quality up to the lateral junction with only a mino r change in the PL wavelength (< 2 nm). These optimized lateral coupli ngs were applied to laser/waveguide butt-couplings. Optical coupling l osses were determined by means of reactive-ion etched waveguides acros s cascades of coupled GaInAsP layers with an emission wavelength of la mbda(G) approximate to 1050 nm. Values as low as 0.12 dB/coupling were determined in cut-back measurements.