We introduce a spectral analysis method in picosecond ultrasonics to derive strain pulse shapes in an opaque sample with known optical properties. The method makes use of both the amplitude and phase of optical transient relative reflectance changes obtained, for example, by interferometry. We demonstrate this method through numerical simulation and by analysis of experimental results for a chromium film.

中文翻译：

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用于确定应变脉冲形状的皮秒超声波振幅和相位回波的频谱分析

我们引入了皮秒超声波光谱分析方法，以得出具有已知光学特性的不透明样品中的应变脉冲形状。该方法利用例如通过干涉测量法获得的光学瞬态相对反射率变化的幅度和相位。我们通过数值模拟和对铬薄膜的实验结果分析来演示该方法。