Fiber-Based High-Energy Femtosecond Pulses Tunable From 920 to 1030 nm for Two-Photon Microscopy

We demonstrate a fiber-based femtosecond laser source, which can deliver 37 MHz, similar to 100 fs laser pulses tunable from 920 nm to 1030 nm with up to 10 nJ pulse energy. Pumped by an ultrafast Yb-doped fiber laser, a short piece of tapered photonic crystal fiber with lower dispersion was used to generate self-phase-modulation filtered for the tunable pulses. We believe that this new type of high-energy ultrafast fiber laser source can be an ideal solution for the two-photon fluorescence microscopy applications.