Light absorption induced thermoelastic and photoacoustic excitation, combined with laser Doppler vibrometry, was utilized to analyze the dynamic mechanical behavior of a microcantilever. The measured frequency response, modal shapes, and acoustic coupling effects were interpreted in the framework of a simple Bernouilli-Euler model and quantitative 3D finite element method (FEM) analysis. Three opto-mechanical generation mechanisms, each initiated by modulated optical absorption and heating, were identified both by an analytical and finite element model. In decreasing order of importance, optically induced cantilever bending is found to be caused by: (i) differences in photoacoustically induced pressure oscillations in the air adjacent to the illuminated and dark side of the cantilever, resulting from heat transfer from the illuminated cantilever to the nearby air, acting as a volume velocity piston, and (ii) thermoelastic stresses accompanying temperature and thermal expansion gradients in the cantilever, (iii) photoacoustically induced pressure oscillations in the air adjacent to the illuminated cantilever holder and frame.

中文翻译：

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通过激光多普勒测振法​​对微悬臂梁的光热和光声响应进行全光动态分析

利用光吸收诱导的热弹性和光声激发，结合激光多普勒测振法​​来分析微悬臂梁的动态机械行为。测量的频率响应、模态形状和声耦合效应在简单的 Bernouilli-Euler 模型和定量 3D 有限元法 (FEM) 分析的框架中进行了解释。通过分析和有限元模型确定了三种光机械生成机制，每种机制均由调制光吸收和加热引发。按照重要性递减的顺序，光感悬臂弯曲是由以下原因引起的：（i）悬臂的照明侧和暗侧附近的空气中光声感生压力振荡的差异，这是由从照明悬臂到悬臂梁的热传递引起的。附近的空气，充当体积速度活塞，以及（ii）悬臂梁中伴随温度和热膨胀梯度的热弹性应力，（iii）照明悬臂梁支架和框架附近空气中光声引起的压力振荡。