Ultrafast ellipsometric interferometry for direct detection of coherent phonon strain pulse profiles
Ultrafast ellipsometric interferometry for direct detection of coherent phonon strain pulse profiles
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DOI：
10.1364/josab.30.001911
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发表时间：
2013-07-01
影响因子：
1.9
通讯作者：
Wright, Oliver B.
中科院分区：
文献类型：
--
作者：
Matsuda, Osamu;Tomoda, Motonobu;Wright, Oliver B.
我们描述了一种超快光学技术来定量检测固体表面的皮秒超声位移，从而获得纵向应变脉冲形状。基于超快椭圆偏振监测千兆赫兹相干声子脉冲的共光路干涉配置记录了倾斜入射时的瞬时光学反射率变化。对于钨薄膜，我们证明了没有光弹效应引起的变形的应变脉冲波形的定量提取，并用双温模型对结果进行了分析，得到电子-声子耦合常数的g值接近3×10(17)Wm(-3)K-1。对数据的分析也揭示了热光效应的贡献。(C)2013年美国光学学会
We describe an ultrafast optical technique to quantitatively detect picosecond ultrasonic displacements of solid surfaces, thus giving access to the longitudinal strain pulse shape. Transient optical reflectance changes recorded at oblique optical incidence with a common-path interferometric configuration based on ultrafast ellipsometry monitor gigahertz coherent phonon pulses. We demonstrate for a tungsten film the quantitative extraction of the strain pulse shape free of distortions arising from the photoelastic effect, and analyze the results with the two-temperature model to obtain the value g approximate to 3 x 10(17) Wm(-3) K-1 for the electron-phonon coupling constant. Analysis of the data also reveals a thermo-optic contribution. (C) 2013 Optical Society of America