In an optical waveguide device, a laser beam is collected to an end face of a channel waveguide, and introduced into a PLZT thin film optical waveguide. The incident laser beam, when emitted from the channel waveguide, diverges in the PLZT waveguide, permeates a thin film lens and is collimated into 0.4 Mm size. When a high frequency voltage is not applied to a comb Al electrode, the laser beam is collected after penetrating through the second thin film and emitted from the end face through the channel waveguide to form an emission beam. When the high frequency voltage is applied to the comb Al electrode, a diffraction grating is formed by an acousto-optic effect, and the laser beam is deflected. The deflected laser beam, when penetrating through the second thin film lens, is collected and emitted from the end face through the channel waveguide in adjacent with the above-described channel waveguide to form a deflected emission beam.