Photothermal excitation of a single-crystalline silicon cantilever for higher vibration modes in liquid
Photothermal excitation of a single-crystalline silicon cantilever for higher vibration modes in liquid
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DOI：
10.1116/1.3077487
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发表时间：
2009-03-01
影响因子：
1.4
通讯作者：
Nishimori, Yuki
中科院分区：
文献类型：
--
作者：
Nishida, Shuhei;Kobayashi, Dai;Nishimori, Yuki
分析了单晶硅悬臂梁在液体中高振动模态下的光热激发。在垂直于悬臂表面的方向上，由热扩散产生的热应力使悬臂弯曲。由于悬臂梁是由均匀材料制成的，因此纵向的热扩散不会产生热应力。因此，具有较小空间周期模态振型的高阶振型容易有效地被激发。比较了405 nm和780 nm两个波长的激发效率。405 nm激光二极管光束在激发第二次弯曲模式时的效率是780 nm光束的2.3-4.2倍。这些激发效率的差异归因于硅的吸收特性，并通过测量透射光功率（损耗光功率）与入射光功率来证实。每个模态的振动幅值都足以在液体中操作动态模态原子力显微镜。(C) 2009美国真空学会[DOI: 10.1116/1.3077487]
The authors analyze photothermal excitation of a single-crystalline silicon cantilever for higher vibration modes in liquid. The cantilever is bent by thermal stress generated by thermal diffusion in the direction perpendicular to the cantilever surface. Because the cantilever is made of a homogeneous material, thermal diffusion in the longitudinal direction does not generate thermal stress. Therefore, the higher vibration modes having small spatially periodic mode shapes are easily and effectively excited. The authors compared the excitation efficiency of two optical wavelengths, 405 and 780 nm. The 405 nm laser-diode beam was found to be 2.3-4.2 times more effective in exciting the second flexural mode compared with the 780 nm beam. These differences in excitation efficiency are attributed to the absorbance characteristics of silicon and were confirmed by measuring the transmitted light power (lost power) against the incident light power. Vibration amplitude of each mode was sufficient to operate dynamic-mode atomic force microscopy in liquid. (C) 2009 American Vacuum Society [DOI: 10.1116/1.3077487]