Acousto-optic spatial frequency filter operating in the intermediate region of acousto-optic interaction

The characteristics of an acousto-optic spatial frequency filter designed for processing of two-dimensional images and operation in the intermediate region of acousto-optic diffraction are investigated. The advantage of such filters over filters operating in a Bragg regime is the possibility of operation at significantly lower acoustic frequencies, which allows the passband of spatial frequencies to be increased and the limiting resolution to be decreased. Transfer functions of diffraction orders are obtained. The use of the first diffraction order is demonstrated to allow selection of the two-dimensional image contour. The two-dimensional image edge enhancement of the image transmitted by optical emission at a wavelength of 0.63 x 10(-4) cm is experimentally demonstrated using a TeO2 spatial filter operating at a frequency of 15 MHz. (C) 2022 Optica Publishing Group