Acousto-optic imaging by means of wide angle tunable acousto-optic filter

The paper is devoted to investigation of wide angle acousto-optic tunable filters, which provide a high rate filtration from infrared to near-ultraviolet range of optical wavelengths with good spectral resolution. The factors decreasing quality of processed images were studied. The research proved that tuning of a filtered wavelength by the wide angle AOTF is accompanied by a defocusing of the processed image in whole. Consideration of this effect in order to compensate the disadvantage resulted in a sufficient enhancement of the image sharpness over the wide range of the filtered optical wavelengths. Spectral measurement of a leaf and analysis of a banknote were carried out in order to demonstrate the operation capability of the instrument.