Precise methods for the measurement of fundamental characteristics of SAW in crystals

This work is devoted to the investigation of two novel precise acoustooptics (AO) methods for the measurement of fundamental characteristics of surface acoustic waves (SAW) in crystals. The first method is based on application of multisectional (MS) comb filter that utilizes the effect of multiple acoustic interference. SAW phase velocity and its dispersion are determined by precise measurement of trap frequencies of narrow interference peaks of the frequency response. The method combines simplicity and convenience of application with the high accuracy. The second method is based on interference of two spatially separated light beams that diffracted from different parts of the SAW. The velocity of the SAW is determined by measurement of dynamic change of the interference pattern´s intensity versus SAW´s frequency. Advantages of this method are moderate accuracy (about 0.02%) and unique opportunity of simultaneous measuring the phase and the group SAW velocities, as well as the dispersion