Laser-generated ultrasonic pulse shapes at solid wedges
Laser-generated ultrasonic pulse shapes at solid wedges
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DOI：
10.1016/j.ultras.2016.04.014
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发表时间：
2016-08-01
期刊：
影响因子：
4.2
通讯作者：
Mayer, Andreas P.
中科院分区：
文献类型：
--
作者：
Pupyrev, Pavel D.;Lomonosov, Alexey M.;Mayer, Andreas P.
聚焦在弹性楔子尖端附近的激光脉冲产生在其顶点引导的声波。声楔波脉冲的形状取决于激励激光脉冲的能量和轮廓以及构成楔块的弹性介质的各向异性。声脉冲形状的表达式已经根据楔形波的模态位移场导出，用于热弹性区域中的激光激励以及通过施加在表面上的压力脉冲进行激励。所考虑的物理量是楔块表面的局部倾斜度，其通过激光探测光束偏转进行光学测量。通过数值计算给出并证实了热弹性区域中脉冲形状的实验结果。它们属于具有两个楔波分支的各向同性锐角楔和矩形硅边缘处的非互易现象。 (C) 2016 Elsevier B.V. 保留所有权利。
Laser pulses focused near the tip of an elastic wedge generate acoustic waves guided at its apex. The shapes of the acoustic wedge wave pulses depend on the energy and the profile of the exciting laser pulse and on the anisotropy of the elastic medium the wedge is made of. Expressions for the acoustic pulse shapes have been derived in terms of the modal displacement fields of wedge waves for laser excitation in the thermo-elastic regime and for excitation via a pressure pulse exerted on the surface. The physical quantity considered is the local inclination of a surface of the wedge, which is measured optically by laser-probe-beam deflection. Experimental results on pulse shapes in the thermo-elastic regime are presented and confirmed by numerical calculations. They pertain to an isotropic sharp-angle wedge with two wedge-wave branches and to a non-reciprocity phenomenon at rectangular silicon edges. (C) 2016 Elsevier B.V. All rights reserved.