High-power broadband laser source tunable from 3.0 µm to 4.4 µm based on a femtosecond Yb:fiber oscillator.

ABSTRACT

We describe a tunable broadband mid-IR laser source based on difference-frequency mixing of a 100 MHz femtosecond Ybfiber laser oscillator and a Raman-shifted soliton generated with the same laser. The resulting light is tunable over 3.0 µm to 4.4 µm, with a FWHM bandwidth of 170 nm and maximum average output power up to 125 mW. The noise and coherence properties of this source are also investigated and described.