SESAM mode-locked Tm:LuYO 3 ceramic laser generating 54-fs pulses at 2048 nm

Mode-locked laser operation near 2.05 µm based on a mixed sesquioxide T m : L u Y O 3 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 ∼ 78 M H z 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.