Tunable high-energy soliton pulse generation from a large-mode-area fiber and its application to third harmonic generation microscopy

We demonstrate high-energy soliton generation from 1580 nm to 2130 nm by using soliton self-frequency shift in a large-mode-area fiber, pumped by a femtosecond fiber laser source. Transformed-limited soliton pulses with 70 fs pulse width and up to 45 nJ pulse energy are obtained. The broad wavelength tuning range and the high soliton pulse energy, together with the robust fiber-based excitation source, offer unprecedented performance, flexibility, and practicality. To demonstrate the application of the soliton pulses, we image the myelin in mouse brain using third harmonic generation microscopy.