GaAs/Ge/GaAs sublattice reversal epitaxy on GaAs (100) and (111) substrates for nonlinear optical devices

Sublattice reversal epitaxy is demonstrated in lattice-matched GaAs/Ge/GaAs (100) and (111) systems using molecular beam epitaxy, and confirmed by ref lection high energy electron diffraction and preferential etching. In the G aAs/Gc/GaAs (100) system, the sublattice reversal is assisted by self-annih ilation of the antiphase domains generated at the GaAs/Ge interface. In the GaAs/Ge/GaAs (111) system, the sublattice reversal results from the unique structure of the As-terminated Ge (111) surfaces. The quality of the subla ttice-reversed GaAs crystal is investigated using cross-sectional transmiss ion electron microscopy. A method to fabricate a periodically domain-invert ed structure using sublattice reversal epitaxy is demonstrated for the GaAs /Ge/GaAs (100) system.