Co-linear Hexa-Mirror-Based Multi-Periodic Structured Illumination Microscopy.

Structured illumination microscopy (SIM) is a robust wide-field optical nanoscopy technique. Several approaches are implemented to improve SIM's resolution capability (∼2-fold). However, achieving a high resolution with a large field of view (FOV) is still challenging. We present tilt-mirror-based multi-periodic SIM for large-FOV super-resolution microscopy. The sample is illuminated by a multi-periodic structured pattern generated by six-beam interference using a custom-designed mirror mount. We achieve 3.16-fold resolution improvement while using a 20×/0.40 numerical-aperture objective that supports a large FOV (0.53 mm × 0.34 mm). This overcomes the high-space-bandwidth product challenge, achieving 9.98-fold improvement. mMP-SIM decouples illumination and collection paths, enabling scalable super-resolution over a large FOV. By using a 28×/0.80 numerical-aperture objective lens, an optical resolution of 170 nm over a 0.40 mm × 0.25 mm imaging area is demonstrated. The proof-of-principle experimental demonstration is performed for both fluorescent beads and a biosample like U2OS (human bone osteosarcoma) cells.