Vibrations of Periodically Poled Lithium Niobate Bar with 0.3-mm Long Domains

The three dimensional vibrations in a periodically poled ZX-cut Lithium Niobate thin bar with 0.3-mm long domains are considered. The acoustical vibrations may be excited by the 1) longitudinal acousto-electric current when a radio frequency voltage is parallel to the x-axis, and 2) transverse electric field when a radio frequency voltage is parallel to the z-axis. The computations by the Final Element Method reveal all the three displacements along the x, y, and z crystallographic axes. The amplitudes may be different for two types of vibration excitations. The positions of peaks in admittance versus frequency correlate with the frequencies of maximum acoustic amplitudes. The superlattice with 0.3-mm long domains along the x-axis is fabricated in the z-cut 0.5-mm-thick wafer. The experimental data on the radio frequency admittance versus frequency is in agreement with the corresponding theoretical computations.