Large-Area, High-Resolution Birefringence Imaging with Polarization-Sensitive Fourier Ptychographic Microscopy

We present polarization-sensitive Fourier ptychographic microscopy (PS-FPM) capable of generating high-resolution birefringence images of optically anisotropic specimens over a large field of view (FoV). FPM produces high-resolution images of transparent samples over a large FoV based on multiple intensity measurements acquired at various illumination angles and ptychographic phase retrieval. We combine this attractive feature of FPM with a single-input-state illumination and polarization-diverse imaging system to achieve the imaging of both complex and birefringence information on transparent objects. Compared to conventional polarization imaging techniques, PS-FPM does not involve any mechanical rotation of the polarizer/analyzer and achieves birefringence imaging with a half-pitch resolution of 0.55 μm over 3.78 mm2 FoV, which corresponds to the space-bandwidth product of 12.5 megapixels. We demonstrate the high-resolution, large-area birefringence imaging capability of PS-FPM by presenting the birefringence images of various anisotropic objects including monosodium urate, Tilia stem, and hemozoin crystals.