We fabricated a hybrid-type acousto-optic (AO) device [Pb(Zr,Ti)O3(PZT)/TiOx/SiO2/SiNx/SiO2/Si] and analyzed AO Bragg diffraction efficiency (ζ) to estimate the applicability of piezoelectric PZT to a Bragg-diffraction-type AO device. A surface acoustic wave (SAW) was generated on the PZT film, and an optical beam (He–Ne laser) was guided in the SiNx film. ζ was varied to 9% in the AO devices fabricated with various AO quality factors (Q) and film thicknesses of top SiO2 and PZT film, respectively. Using the results, we qualitatively analyzed the decay of SAW power to the film depth direction and AO figure of merit (M2=0.75×10-18 s3/g) of the SiNx film. © 2003 American Institute of Physics.