Quantitative study on the nonlinear piezoelectric effect in KNbO3 single crystals for a highly efficient surface acoustic wave elastic convolver

In this article we describe quantitative studies on the nonlinear piezoelectric effect in KNbO3 single crystals for a highly efficient surface acoustic wave elastic convolver. First, we demonstrate that a simple measurement of the nonlinear piezoelectric constant of e(355) is very effective for quantitative estimation of the efficiency of an elastic convolver. Next, the third-order piezoelectric constants, e(355), e(333), and e(344), in rotated Y-cut KNbO3 substrates are measured by varying the velocity under an applied electric field. Using the third-order piezoelectric constants measured, quantitative estimations of the convolution efficiency are discussed. (C) 2000 American Institute of Physics. [S0021-8979(00)05307-X].