[Figure 1] (a) Schematic of compressed time-reversal matrix microscope. Random speckle fields generated by a rotating diffuser sequentially illuminate the sample underneath an aberrating medium, and the reflected speckle fields are measured by an off-axis digital holographic microscope. BS: beam splitter. OL: objective lens. (b) Examples of measured hologram images for speckle fields. (top : intensity, bottom : phase). Credit: DOI: 10.1038/s41377-021-00705-4