rSHG: Re-scan Second Harmonic Generation Microscopy

• Main Authors: Stanciu, Stefan G, Hristu, Radu, Stanciu, George A, Tranca, Denis E, Eftimie, Lucian, Dumitru, Adrian, Costache, Mariana, Stenmark, Harald A, Manders, Harm, Cherian, Amit, Tark-Dame, Mariliis, Manders, Erik M. M
• Format: Journal Article
• Language: English
• Published: 07-07-2022
• Subjects: Physics - Biological Physics; Physics - Optics
• DOI: 10.48550/arxiv.2207.02002

Second Harmonic Generation Microscopy (SHG) is generally acknowledged as a
powerful tool for the label-free 3D visualization of tissues and advanced
materials, with one of its most popular applications being collagen imaging.
Although the great need, progress in super-resolved SHG imaging lags behind the
developments reported over the past years in fluorescence-based optical
nanoscopy. In this work, we quantitatively show on collagenous tissues that by
combining SHG imaging with re-scan microscopy resolutions that surpass the
diffraction limit with ~1.4x become available. Besides Re-scan Second Harmonic
Generation Microscopy (rSHG), we demonstrate as well super-resolved Re-scan
Two-Photon Excited Fluorescence Microscopy (rTPEF). These two techniques are
implemented by modifying a Re-scan Confocal Microscope (RCM), retaining its
initial function, resulting thus in a multimodal rSHG/rTPEF/RCM system. Given
the simplicity and flexibility of re-scan microscopy, we consider that the
reported results are likely to augment the number and nature of applications
relying on super-resolved non-linear optical imaging.