Quantitative phase imaging and holography allow highly sensitive detection of phase changes, for example of surface non-uniformities or refractive index structures in the volume of a sample. For many applications, wide field-of-view (FoV) and high phase sensitivity are required. In this work, we propose and demonstrate a novel implementation of lens-free phase imaging with phase-shifting interferometry and multi-angle illumination that enhances axial resolution and image quality, enabling ultra-high phase sensitivity with optical path difference background root-mean-square noise of 0.2 nm, while operating over a wide FoV.
