Computational microscopy beyond perfect lenses.

We demonstrate that in situ coherent diffractive imaging (CDI), which leverages the coherent interference between strong and weak beams to illuminate static and dynamic structures, can serve as a highly dose-efficient imaging method. At low doses, in situ CDI can achieve higher resolution than perfect lenses with the point spread function as a delta function. Both our numerical simulations and experimental results demonstrate that combining in situ CDI with ptychography can reduce the required dose by up to two orders of magnitude compared with ptychography alone. We anticipate that computational microscopy based on in situ CDI can be applied across various imaging modalities using photons and electrons for low-dose imaging of radiation-sensitive materials and biological samples.