Metasurface-enabled single-shot isotropic differential interference contrast (DIC) microscopy

Differential interference contrast (DIC) microscopy plays an important role in biological sample imaging, with the merit of high contrast, low phototoxicity and no fluorescent label required. Commercial DIC microscopy using Nomarski or Wollaston prism is based on the interference of two polarized waves with the lateral differential offset (shear) and axial phase-shift (bias). However, the shear generated by these prisms is limited to the rectilinear direction, unfortunately resulting in anisotropic contrast imaging. Here we propose an ultracompact metasurface-assisted isotropic DIC (i-DIC) microscopy, that converts the rectilinear shear into rotationally symmetric along radial direction, enabling single-shot isotropic imaging capabilities. The i-DIC presents a complementary fusion of typical meta-optics and traditional microscopes, and showcases the promising and synergetic advancements in edge detection, particle motion tracking, and label-free cellular imaging.