2.5-gigapixel compact stitching-free Fourier ptychographic imager

To address the long-standing challenge that Fourier ptychographic microscopy (FPM) struggles to simultaneously achieve high throughput, compact footprint, and low cost due to its conventional long-focal-length 4F optical path, we propose and demonstrate a high-throughput, portable FPM system based on a tandem infinity-corrected dual-objective architecture. This work achieves, for the first time, to the best of our knowledge in FPM, a space-bandwidth product on the order of 2.5 gigapixels-an improvement of more than an order of magnitude over comparable systems and the highest level reported to date. The system achieves a synthetic NA of 0.54 experimentally across a 13.86-mm-diameter field of view, within a footprint of only 80 mm  ×  80 mm  ×  400 mm and at a cost below USD$10,000. To comprehensively characterize its performance, we validated the system on a USAF resolution target and on an interstitial-pneumonia histopathology section. The results demonstrate that the proposed platform achieves an effective balance among imaging throughput, system size, and hardware cost, laying the groundwork for the practical deployment of FPM in resource-constrained settings such as portable digital pathology and point-of-care diagnostics.