Acousto-optic imaging (AOI) enables optical-contrast imaging deep inside scattering samples via localized ultrasound-modulation of scattered light. While AOI allows optical investigations at depths, its imaging resolution is inherently limited by the ultrasound wavelength, prohibiting microscopic investigations. Here, we propose a computational imaging approach that allows optical diffraction-limited imaging using a conventional AOI system. We achieve this by extracting diffraction-limited imaging information from speckle correlations in the conventionally detected ultrasound-modulated scattered-light fields. Specifically, we identify that since “memory-effect” speckle correlations allow estimation of the Fourier magnitude of the field inside the ultrasound focus, scanning the ultrasound focus enables robust diffraction-limited reconstruction of extended objects using ptychography (i.e., we exploit the ultrasound focus as the scanned spatial-gate probe required for ptychographic phase retrieval). Moreover, we exploit the short speckle decorrelation-time in dynamic media, which is usually considered a hurdle for wavefront-shaping- based approaches, for improved ptychographic reconstruction. We experimentally demonstrate noninvasive imaging of targets that extend well beyond the memory-effect range, with a 40-times resolution improvement over conventional AOI.

中文翻译：

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声光图谱

声光成像 (AOI) 可通过散射光的局部超声调制实现散射样品内部深处的光学对比成像。虽然 AOI 允许在深度进行光学研究，但其成像分辨率本质上受到超声波波长的限制，禁止进行微观研究。在这里，我们提出了一种计算成像方法，该方法允许使用传统 AOI 系统进行光学衍射限制成像。我们通过从常规检测到的超声调制散射光场中的散斑相关性中提取衍射极限成像信息来实现这一点。具体来说，我们确定由于“记忆效应”散斑相关性允许估计超声焦点内场的傅立叶幅度，扫描超声焦点可以使用 ptychography 对扩展对象进行稳健的衍射限制重建（即，我们利用超声焦点作为 ptychographic 相位检索所需的扫描空间门探针）。此外，我们利用动态媒体中短的散斑去相关时间，这通常被认为是基于波前整形的方法的障碍，用于改进 ptychographic 重建。我们通过实验证明了远超出记忆效应范围的目标的无创成像，分辨率比传统 AOI 提高了 40 倍。这通常被认为是基于波前整形的方法的障碍，以改进 ptychographic 重建。我们通过实验证明了远超出记忆效应范围的目标的无创成像，分辨率比传统 AOI 提高了 40 倍。这通常被认为是基于波前整形的方法的障碍，以改进 ptychographic 重建。我们通过实验证明了远超出记忆效应范围的目标的无创成像，分辨率比传统 AOI 提高了 40 倍。