[15p-D305-1~13] 1.6 Ultrasonics

△ [15p-D305-3] Analysis of Longitudinal Leaky Surface Acoustic Waves on LiTaO₃ or LiNbO₃ Thin Plate Bonded to Similar-material Substrate

〇Takumi Fujimaki¹, Masashi Suziki¹, Shoji Kakio¹ (1.Univ. of Yamanashi)

Keywords:longitudinal leaky surface acoustic wave, Similar-material bonded structure, LiTaO3, LiNbO3

In this report, we investigated theoretically longitudinal leaky surface acoustic waves (LLSAWs) on similar-material bonded structures for LiTaO₃(LT) or LiNbO₃(LN). An X31°Y-LT or X36°Y-LN with the largest coupling factor for LLSAW was assumed as a thin plate, and an YZ-LT or YZ-LN was assumed as a support substrate. As a result, the same values for resonance Q_r and anti-resonance Q_a were obtained. For instance, Q_r of 820 and antiresonance Q_a were obtained for X31°Y-LT(h/λ=0.21)/YZ-LT. Q_r of 870 and Q_a of 880 were also obtained for X36°Y-LN(h/λ=0.04)/YZ-LN.
The values of admittance ratio for the LT and LN similar-material bonded structures were 60 and 80 dB, respectively.
In addition, it was found that the maximum amplitude of the main displacement u₁ was large and the leakage of u₂ and u₃ into the substrate was suppressed for the LT similar-material bonded structure compared with the single YZ-LT.