Simultaneous 2-photon and 3-photon multimodal signal acquisition for multiphoton microscopy

Abstract

We report on a simultaneous 2-photon and 3-photon signal acquisition method for label-free multiphoton microscopy. With dual excitation wavelengths of 1580 nm and 790 nm and a set of filter designs, multiple contrasts including second harmonic generation, third harmonic generation, and two-photon-excitation-fluorescence images are detected and separated. The spectrum of the nonlinear signals is measured and verified by a spectrometer. Depth-resolved multimodal images are demonstrated on a silicon photonic chip and leaf samples. The simultaneous 2-and 3-photon microscopy is shown to have great potential for label-free in-vivo imaging.