Two generation mechanisms—optical perturbation and acoustic radiation force (ARF)—were investigated where high frame rate ultrasound imaging was used to track the propagation of induced SAWs. We compared ARF-induced SAWs with laser-induced SAWs generated by laser beam irradiation of the uniformly absorbing tissue-like viscoelastic phantom, where light was preferentially absorbed at the surface. We also compared the frequency content of SAWs generated by ARF versus pulsed laser light, using the same duration of excitation. Differences in the SAW bandwidth were expected because, in general, laser light can be focused into a smaller area. Finally, we compared wave generation and propagation when the wave’s origin was below the surface. We also investigated the relationship between shear wave amplitude and optical fluence. The investigation reported here can potentially extend the applications of laser-induced SAW generation and imaging in life sciences and other applications.

中文翻译：

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激光激发诱导的表面声​​波的超快超声成像与声辐射力的比较

研究了两种生成机制——光学扰动和声辐射力 (ARF)，其中高帧率超声成像用于跟踪感应 SAW 的传播。我们将 ARF 诱导的 SAW 与由激光束照射均匀吸收的组织状粘弹性体模产生的激光诱导的 SAW 进行了比较，其中光优先在表面被吸收。我们还使用相同的激发持续时间比较了 ARF 与脉冲激光产生的 SAW 的频率内容。SAW 带宽的差异是意料之中的，因为通常激光可以聚焦到更小的区域。最后，我们比较了波的起源在地表以下时的波产生和传播。我们还研究了剪切波振幅和光通量之间的关系。