Kerr-Lens Mode-Locked Middle IR Polycrystalline Cr:ZnS Laser with a Repetition Rate 1.2 GHz

We report flexible design of femtosecond middle-IR lasers with a broad range of repetition rates 0.08-1.2 GHz. The lasers emit few-cycle pulses with 4-16.4 THz bandwidth, 0.1-21 nJ energy at 2.4 µm wavelength.