华北电力大学 能源动力与机械工程学院, 北京 102206
该文采用多物理场耦合的有限元模型, 探究了保护层Al2O3厚度对以LGS为压电基底、Pt为电极的声表面波(SAW)高温传感器中声波特性及器件性能的影响。结果表明, 随着Al2O3保护层厚度的增加, 声表面波在L波方向的振动位移增加, 在SH波和SV波方向的振动位移减弱, 当保护层归一化厚度为6.25%时, 其能量向衬底内部扩散; 当保护层归一化厚度为18.75%时, Rayleigh波消失, 此时为体波BAW模式; 增加Al2O3保护层, 波速v、机电耦合系数K2显著升高; 一阶频率温度系数τf, 1和转换温度随保护层厚度的增加而升高。利用Al2O3薄膜对SAW温度传感器进行结构优化, 为了获得良好的综合性能, 归一化厚度应该在0.94%附近。
声波模式 SAW传感器 Al2O3保护层 有限元 acoustic mode SAW sensor Al2O3 protective layer finite element
Author Affiliations
Abstract
1 Department of Optical Engineering, School of Electronic Science & Applied Physics, Hefei University of Technology, Hefei 230601, China
2 School of Instrument Science and Opto-electronics Engineering, Hefei University of Technology, Hefei 230009, China
3 R&D Center of High Power Laser Components, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
4 Research Center for Advanced Photon Technology, Toyota Technological Institute, Nagoya 468-8511, Japan
Brillouin gain spectra (BGS) in an As2Se3 photonic crystal fiber (PCF) are investigated numerically. The profiles of the BGS are simulated by calculating the characteristics of different-order optical and acoustic waves in the PCFs with different core diameters. For the small-core PCF, there are two peaks in BGS, but there is only one peak for the large-core PCF. We also reveal that in the small-core PCF, the difference of Brillouin frequency shift between the LP01 and LP11 modes is obvious, while it is not obvious in the large-core PCF. The Brillouin threshold increases with the core diameter increasing.
stimulated Brillouin scattering optical mode acoustic mode chalcogenide fiber photonic crystal fiber Chinese Optics Letters
2020, 18(1): 010602
分析了影响光声信号大小的多种因素，特别是光声池的大小对光声信号的影响。使用适当尺寸的圆柱形光声池并使其工作在一阶径向共振状态，结合光学长程技术，显著提高了光声信号的信噪比。用钛宝石激光器作光源，光声光谱仪的探测灵敏度达8.5×10-9 cm-1(1:1信噪比)，并测出砷烷分子振动量子数为6的高分辨泛频谱。
光声光谱 声学模式 光学长程 泛频谱
