Epitaxial MgO on GaAs(111) as a buffer layer for z-cut epitaxial lithium niobate

Abstract
The epitaxial system z‐lithium niobate on GaAs(111)A and GaAs(111)B has been demonstrated by in situ pulsed laser deposition both with and without intermediate layers of MgO(111). The in‐plane epitaxial relationships are LiNbO3[110]∥GaAs[2̄11] and [21̄1̄] indicating the existence of 180° boundaries in the LiNbO3 both with and without the MgO layer, which grows cube‐on‐cube with the GaAs. Out‐of‐plane texture is typically 1.0° and 1.2° for the MgO and LiNbO3 layers, respectively. In‐plane texture is typically 2.8° and 4.5° for the MgO and LiNbO3 layers, respectively. This epitaxial system may be useful for monolithic electro‐optic or frequency doubling applications in conjunction with semiconductor laser diodes.