SESAM mode-locked Tm:LuYO₃ ceramic laser generating 54-fs pulses at 2048  nm

Mode-locked laser operation near 2.05 µm based on a mixed sesquioxide Tm:LuYO₃ ceramic is demonstrated. Continuous-wave and wavelength-tunable operation is also investigated. Employing a GaSb-based semiconductor saturable absorber mirror as a saturable absorber, a maximum average output power of 133 mW is obtained for a pulse duration of 59 fs. Pulses as short as 54 fs, i.e., eight optical cycles are generated at a repetition rate of ∼78MHz with an average output power of 51 mW. To the best of our knowledge, this result represents the shortest pulse duration ever achieved from Tm-based solid-state mode-locked lasers.