Color image scanning using acousto-optic interaction with surface waves

The scanning of a one dimensional multi-color light intensity distribution by means of the acousto-optic interaction using acoustic surface waves is presented. In the experiment laser sources of different color are used to image a multi-color transparency into the surface region of a LiNbO surface acoustic wave light modulator. An rf acoustic pulse propagating on the LiNbO surface scans this image and diffracts the light. Each color component is then individually detected in the diffracted light by means of a photodiode. Four different device schemes are compared, being classified by the configuration through which the light and acoustic beams interact. Applications of the system to producing a real-time signal of the Fourier transform of an optical transparency ana to electronic focusing by use of chirped acoustic waves are also discussed. Argon and HeNe lasers are used as light sources, and center frequency of the surface acoustic wave varies from 1+5 to 100 MHz.