High Power Soliton Self-Frequency Shift With Improved Flatness Ranging From 1.6 to 1.78 $\mu{\rm m}$

We report on the demonstration of a high power tunable femtosecond fiber laser based on soliton self-frequency shift in a large mode area photonic crystal fiber. The laser provides up to 13 nJ pulse energy, ~ 550 mW average power, and wavelength tuning range from 1600 to 1780 nm. The pulse duration is sub-100 fs over the entire tuning range. We have also demonstrated a novel way of tuning the laser output wavelength using chirp control which has allowed us to achieve higher average output power within the tuning range. We believe the laser system will be useful for high speed deep tissue multiphoton bio-imaging and difference frequency generation to create high power tunable mid-IR radiation.