Label-free microscopy exploits light scattering to obtain a three-dimensional image of biological tissues. However, light propagation is affected by aberrations and multiple scattering, which drastically degrade the image quality and limit the penetration depth. Multi-conjugate adaptive optics and time-gated matrix approaches have been developed to compensate for aberrations but the associated frame rate is extremely limited for three-dimensional imaging. Here we develop a multi-spectral matrix approach to solve these fundamental problems. On the basis of a sparse illumination scheme and an interferometric measurement of the reflected wave field at multiple wavelengths, the focusing process can be optimized in post-processing for any voxel by addressing independently each frequency component of the reflection matrix. A proof-of-concept experiment shows a three-dimensional image of an opaque human cornea over a 0.1 mm³ field of view at a 290 nm resolution and a 1 Hz frame rate. This work paves the way towards a fully digital microscope allowing real-time, in vivo, quantitative and deep inspection of tissues.

无标记显微镜利用光散射来获得生物组织的三维图像。然而，光传播受到像差和多重散射的影响，这会大大降低图像质量并限制穿透深度。已经开发了多共轭自适应光学和时间选通矩阵方法来补偿像差，但相关的帧速率对于三维成像来说极其有限。在这里，我们开发了一种多光谱矩阵方法来解决这些基本问题。基于稀疏照明方案和多波长反射波场的干涉测量，可以通过独立地处理反射矩阵的每个频率分量，在任何体素的后处理中优化聚焦过程。概念验证实验显示了不透明人类角膜的三维图像，其视野范围为 0.1 mm ³ ，分辨率为 290 nm，帧速率为 1 Hz。这项工作为全数字显微镜铺平了道路，可以对组织进行实时、活体、定量和深度检查。