Super-depth imaging with volumetric reflection matrix

To visualize objects embedded within a scattering medium, correcting sample-induced wave distortions is crucial. Traditional methods optimize signal waves in individual 2D images, but our study introduces volumetric reflection-matrix microscopy (VRM), a novel technique that reconstructs object images with ideal diffraction-limited resolution, even in complex scattering media. VRM uses a wavelength-tunable laser and galvanometer mirror to scan wavelength and illumination angle, creating a coherent volumetric reflection matrix with a spectral bandwidth of 225 nm and angular coverage up to NA 1.0. By applying a framework based on object momentum conservation, we correct spectro-angular dispersion, achieving ultrahigh volumetric resolution. We also introduce two novel reconstruction methods: progressive depth imaging and volumetric dispersion correction, leveraging the full volume's wave correlation to overcome multiple scattering and surpass the limitations of conventional 2D approaches, enabling greater imaging depth in complex media.