NOTCH SPATIAL-FILTERING WITH AN ACOUSTOOPTIC MODULATOR

The role of acousto-optic (AO) modulators in programmable real-time im age processing has recently been demonstrated. For fully investigating the image-processing capabilities of the AO modulator, general techni ques to derive spatial transfer functions are needed for a variety of physical situations. We develop a technique to determine the spatial t ransfer functions numerically for various cases of beam incidence on a n AO modulator. Normal incidence and incidence at twice the Bragg angl e are investigated as examples for which double-sided and single-sided notch spatial filtering, respectively, are achieved. The observed spa tial-filtering characteristics are reconciled with simple intuitive ph ysical arguments. (C) 1998 Optical Society of America.