Two-dimensional optical deflector

TLDR: In this article, the authors proposed a method to increase the deflection angle of an optical beam by changing the heating temperature of an electric heating unit to change the refractive index of a thin film optical waveguide near an exit end face and deflecting the optical beam which is emitted from the exit-end face, in the direction vertical to the surface of the thin-film optical wave guide.

Abstract: PURPOSE:To increase the deflection angle of an optical beam, by changing the heating temperature of an electric heating unit to change the refractive index of a thin film optical waveguide near an exit end face and deflecting the optical beam, which is emitted from the exit end face, in the direction vertical to the surface of the thin film optical waveguide. CONSTITUTION:When comb-shaped electrodes 3 are driven with a certain frequency (f), surface acoustic waves SAW of a wavelength are generated on a thin film optical waveguide 2, and the refractive index is changed at a periodic pitch in the optical waveguide 2, and an optical beam P1 of the wavelength which is incident at an angle theta to the wave guide surface becomes a Bragg-diffracted optical beam P2 reflected by the wave surface if the condition of an expression Iis satisfied. When the driving frequency (f) for comb-shaped electrodes 3 is changed to f+ or -DELTAf, the advance direction of the Bragg-diffracted optical beam P2 is changed in a range of an angle DELTAtheta. That is, the oscillation frequency of a high frequency oscillator 7 is changed continuously to change continuously the advance direction of the optical beam P2.