Acoustooptic Bragg deflectors (ABDs) with high diffraction efficiencies were fabricated using ZnO thin films deposited on sapphire, glass, and Si substrates by an RF magnetron sputtering system. Optical waveguide losses of the ZnO films were about 0.5 dBcm(-1). Diffraction efficiencies of 95 and 98% for the TE(0) mode beam (at 632.8 nm) were accomplished by acoustic powers of 90 mW in a ZnO film on glass and 80 mW in a ZnO film on Si, respectively. The diffraction efficiencies of the ABD using a ZnO film on sapphire with interdigital transducers of different Q values and with the surface-acoustic-wave propagating along and perpendicular to the c -axis of the ZnO film were also determined.