Brillouin imaging is an emerging optical elastography technique that is able to generate maps of the mechanical properties at microscale with great potential in biophysical and biomedical fields. A key parameter is its spatial resolution, which is usually identified with that of the confocal microscope coupled to the Brillouin interferometer. Conversely, here we demonstrate that the mean free path of acoustic phonons plays a major role in defining the resolution, especially for high numerical aperture confocal setups. Surprisingly, the resolution of elastography maps may even deteriorate when decreasing the scattering volume.

中文翻译：

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关于布里渊成像的实际空间分辨率。

布里渊成像是一种新兴的光学弹性成像技术，能够在微观尺度上生成机械性能图，在生物物理和生物医学领域具有巨大潜力。关键参数是它的空间分辨率，通常由与布里渊干涉仪耦合的共聚焦显微镜确定。相反，在此我们证明，声子的平均自由程在定义分辨率中起着重要作用，尤其是对于高数值孔径共焦设置而言。令人惊讶的是，当减小散射体积时，弹性成像图的分辨率甚至可能恶化。