Interactions between High‐Frequency Acoustical Waves in Lithium Niobate

TLDR: In this article, the interaction between two colinear longitudinal acoustical waves of frequencies 930 MHz and 2770 MHz simultaneously excited in LiNbO3 was studied.

Abstract: We have studied the interaction between two colinear longitudinal acoustical waves of frequencies 930 MHz and 2770 MHz simultaneously excited in LiNbO3 (cut 001). The acoustical waves were produced by placing a crystal in an intense electric field of a cavity resonating with two distinct frequencies. The waves thereby produced interact at the surface of the crystal (when the acoustical waves are produced) and in the volume when the waves are propagated, forming harmonies and waves of mixed frequencies mF1±nF2 (F1 and F2 are frequencies of the fundamental waves, m and n are integers). We have detected waves of frequencies 2F1 and F2 − F1 in the second end of the crystal. The deformation amplitudes detected at these frequencies depend on the length of the crystal studied. The interaction observed, along the direction [001] of LiNbO3, depends then on the interaction length between waves in the crystal and has been interpreted by considering only the nonlinear effects in the propagation of the acoustical waves.