Aberration-corrected Fourier ptychographic birefringence microscopy using single-input-state lenslet-integrated hybrid LED illumination

Abstract

Quantitative imaging of optical anisotropy over large spatial scales is of great significance for revealing spatial heterogeneity in structural organization and molecular arrangement at scales relevant to functional and mechanical performance. However, existing polarization-sensitive (PS) imaging methods face several limitations, including system complexity, long acquisition times, and sensitivity to system imperfections such as optical aberrations and misalignment. Here, we present aberration-corrected Fourier ptychographic birefringence microscopy (AC-FBM), a method that enables large-area, high-resolution birefringence imaging with significantly improved efficiency and robustness. AC-FBM employs a single-input-state, lenslet-integrated LED illuminator to obtain high-intensity polarized illumination with uniform wave vectors and integrates angular ptychographic imaging via a closed-form method with hybrid multiplexed illumination to achieve high space–bandwidth-product (SBP) PS imaging. This design enables image acquisition with substantially shorter exposure times and improved signal-to-noise ratio while satisfying the analyticity conditions required for rapid analytic image and pupil recovery. Our AC-FBM prototype achieves an SBP of approximately 3.5 megapixels at a spatial resolution of 0.62 µm over a 1.27 × 1.06 mm2 field of view, representing a fourfold improvement beyond the coherent diffraction limit. This performance requires only 12 measurements, reducing acquisition time by more than 240-fold and substantially lowering computational complexity compared to the PS Fourier ptychographic microscopy. Experimental validation on biological samples—including a plant stem, mouse brain tissue cross-sections, and dynamic potato starch granules—demonstrates that AC-FBM enables robust, high-throughput, quantitative characterization of anisotropic materials.