40 W SESAM-modelocked Ho:YAG thin-disk laser at 2090 nm

High power ultrafast lasers in the short-wave mid-IR wavelength region (2-3 µm) are of great interest for a large number of applications in science and technology. Finding paths to increase the average power of ultrafast laser systems directly emitting in this wavelength region has seen particularly strong interest, due to the potential of these sources as direct drivers for the generation of XUV, mid-IR and THz. Among different power-scalable technologies, the development of thin-disk lasers (TDLs) at 2 µm is very promising for power and energy scaling of ultrafast lasers in this wavelength range, but only very few results have so far conclusively shown this potential [1] , [2] . Recently, we have shown the potential of Ho:YAG for further power scaling by demonstrating a cw, single fundamental-mode 2-µm TDL with >100 W and 54% optical-to-optical efficiency, representing the highest power TDL around 2 µm [3] . In the present work, we report first high-power modelocking SESAM-modelocking of this system, reaching an average power of 40-W in ps-pulses, which respresents the highest average power from a modelocked oscillators in the wavelength region.