Rapid mesoscale multiphoton microscopy of human skin

We present a multiphoton microscope designed for mesoscale imaging of human skin. The system is based on two-photon excited fluorescence and second-harmonic generation, and images areas of similar to 0.8x0.8 mm(2) at speeds of 0.8 fps (800x800 pixels; 12 frame averages) for high signal-to-noise ratio, with lateral and axial resolutions of 0.5 mu m and 3.3 mu m, respectively. The main novelty of this instrument is the design of the scan head, which includes a fast galvanometric scanner, optimized relay optics, a beam expander and high NA objective lens. Computed aberrations in focus are below the Marechal criterion of 0.07. rms for diffraction-limited performance. We demonstrate the practical utility of this microscope by ex-vivo imaging of wide areas in normal human skin. (C) 2016 Optical Society of America