By means of an ultrafast optical technique, picosecond acoustic strain pulses in a transparent medium are tomographically visualized at GHz frequencies. The strain distribution in BK7 glass is reconstructed from time-domain reflectivity changes of 415-nm probe light as a function of the optical incidence angle with 1 ps temporal and 120 nm spatial resolutions, enabled by automated angle scanning. The latter resolution is achieved owing to the commensurate acoustic wavelength. Applications include imaging strain, carrier and temperature distributions on ultrashort timescales.

中文翻译：

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使用可见光自动角度扫描探测对皮秒声应变脉冲进行断层扫描重建

借助超快光学技术，可以在 GHz 频率下对透明介质中的皮秒声应变脉冲进行层析成像可视化。 BK7 玻璃中的应变分布是根据 415 nm 探测光的时域反射率变化重建的，作为光学入射角的函数，时间分辨率为 1 ps，空间分辨率为 120 nm，通过自动角度扫描实现。后一种分辨率是由于相应的声波波长而实现的。应用包括超短时间尺度上的应变、载流子和温度分布成像。