Acousto-optic diffraction of blue and red light in GaN

The diffraction of guided optical waves on surface acoustic waves in a GaN layer grown by metalorganic chemical-vapor deposition on a (0001) sapphire substrate has been experimentally studied. The measurements have been performed at optical wavelengths 442 and 633 nm for the acoustic wavelength of 16 mum. The acousto-optic diffraction regime was close to the pure Bragg diffraction regime. The advantage of considerably lower acoustic power required at the shorter optical wavelength for diffraction is demonstrated. Our results show the potential of GaN-based structures for the development of blue acousto-optical devices. (C) 2002 American Institute of Physics.