EN
In this paper, an introduction to the design, fabrication, evaluation, and application of acousto-optic modulators using the Bragg diffraction of an optical guided wave in a channel optical waveguide due to a surface acoustic wave is provided. First, the surface acoustic wave mode dependence in the acousto-optic Bragg diffraction was discussed by considering the surface acoustic wave power required for the maximum diffraction P_{{100}} calculated using coupled mode theory and the measured P_{{100}} in Ti-diffused planar optical waveguides fabricated on LiNbO_{{3}} substrates. Next, performances of several devices that the author and the coworkers developed are reviewed. These include a waveguide-type acousto-optic modulator using a tapered crossed-channel proton-exchanged optical waveguide on a 128°-rotated Y-cut LiNbO_{{3}} substrate for an optical wavelength of 1.55 μm, a monolithically integrated tandem acousto-optic modulator in which several waveguide-type acousto-optic modulators are connected in tandem on the same substrate, and a waveguide-type acousto-optic modulator in which laser lights of the three primary colors, red, green, and blue, can be modulated by the same modulator at the same driving frequency.