Ultrafast mid-IR Fe:ZnSe laser

We report the graphene-based passive mode-locking in Fe:ZnSe. The laser delivers 415 mW average power output radiation at a wavelength of 4.4 μm being pumped by 7-W fiber Er:ZBLAN laser. A pulse duration of 732 fs retrieved from the first-order autocorrelation function. Besides, we observed pulsed nanosecond oscillation under continuous-wave pumping and strong amplitude modulation caused by Kerr self-focusing. A numerical simulation of the soliton propagation in a laser cavity using the nonlinear Schrödinger equation supports obtained results. Such simple and effective ultrafast mid-IR high-repetition-rate coherent sources are designed to become a valuable tool in various fields of photonics.