Epitaxial growth on optical gratings for distributed feedback GaAs injection lasers

Good quality epitaxial overgrowth of Al_0.3Ga_0.7As on corrugated GaAs and Al_0.12Ga_0.88As surfaces has been achieved by molecular-beam epitaxy. The electrical properties of the interface appear to be equivalent to those prepared by LPE without growth interruption. The corrugations were third order Bragg gratings of ～0.37 μm period and ～0.20 μm depth and were formed by ion milling. Separate confinement heterostructure injection lasers with these periodic corrugations in the optical cavity have demonstrated lasing behavior characteristic of distributed feedback. They have operated with room-temperature threshold current densities as low as 2.2 kA/cm². These results suggest that the MBE overgrowth is a useful technique for the fabrication of integrated optoelectronic structures which include active devices.