Improvement of the acousto-optic cell function by piezotransducer sectioning

Abstract

The set of equations describing the acousto-optic diffraction problem and bounding the amplitudes of transmitted and diffracted light and their solution that determines the optical wave amplitudes at the acousto-optic cell output is presented. It is shown that when the piezotransducer is divided in sections, the non-uniform distribution of an acoustic amplitude can be obtained; this can lessen the acousto-optic cell transmission function side lobes maxima. Two methods of the piezotransducer sections connection-symmetrical and in series-are analysed. The calculation testified that the diminution of side lobe intensity is proportional to the number of sections. The affection of the phase shift between sections upon the form of the transmission function was investigated. It was shown that a small phase delay of electric signals feeding the neighbouring sections result in the asymmetry of the transmission function and in its main maximum shift.