High Spatial and Angular Resolution Wavefront Sensing Based on the Random Phase Modulated Diffraction Effect

Abstract Angle‐enabled wavefront sensing based on metasurface can realize high‐spatial‐resolution wavefront reconstruction without requiring reference‐beam interference, which has great potential in applications in various fields ranging from biological cell characterization to surface metrology. However, the current metasurface wavefront encoding scenario exhibits weak modulation capabilities with an oversimplified angular modulation function, resulting in a limited angular resolution. Here, a wavefront sensor based on random wavefront coding with a diverse angle response function, achieved through a diffractive optical element (DOE), is proposed, which can simultaneously provide a large dynamic range, high spatial resolution, and high angular resolution. By experimentally calibrating the mapping between DOE diffraction patterns and incident angles, one can precisely decode the local incident angles. Combined with zonal wavefront reconstruction algorithms, the unknown wavefront can be reconstructed accurately. Owing to the drastically improved resolution, the wavefront sensor can be used for quantitative phase imaging, which shows a good capability in surface topography measurement for both static and dynamically evolving samples. The method provides valuable insights for high‐resolution wavefront sensing and quantitative phase imaging.