Kerr-lens mode-locked Ho:CALYO laser at 2.1 μm

We report on a Kerr-lens mode-locked Ho laser operating at 2.1 μm, based on a disordered structure crystal Ho:CALYO. The laser-generated ultrashort pulses with a pulse duration of 177 fs and an average output power of 0.81 W at a repetition rate of 90 MHz, with an optical-to-optical efficiency of 11%. By optimizing the system for shorter pulse durations, we achieved pulses as short as 166 fs, though at a reduced output power of 0.18 W. The pulse duration and output power limitations were analyzed and discussed.