Abstract: The possibility of determining the frequency of an acoustically active acoustic wave has been studied. The studies were carried out using the Bragg diffraction method of light on a high-frequency acoustic wave in a lanthanum gallosilicate crystal oriented with high accuracy along the third-order crystallographic axis. Transverse acoustic waves were excited in the range of 0.8-1.6 GHz using lithium niobate piezoelectric transducers. The attenuation coefficient of acoustic waves was previously determined by the pulse ultrasonic method. An expression is obtained for the magnitude of the specific rotation of the plane of polarization of an acoustic wave depending on the effective constant of the acoustic activity tensor and the effective elastic constant. It has been established that specific acoustic activity depends on the frequency of the acoustic wave according to a quadratic law. The results of the study showed that the proposed method makes it possible to determine the frequency of an acoustically active acoustic wave in a dynamic mode with an accuracy of up to 1 %.

Keywords: Acoustic wave, Acoustical activity, Bragg light diffraction, Frequency, Diffracted light intensity, Lanthanum gallosilicate crystal.

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