C. Gaida
F. Stutzki
M. Gebhardt
F. Jansen
A. Wienke
U. Zeitner
F. Fuchs
C. Jauregui
D. Wandt
D. Kracht
J. Limpert
A. Tünnermann

Sub-700fs pulses at 152 W average power from a Tm-doped fiber CPA system

SPIE Photonics West: LASE
7.-12. Februar
San Francisco
Type: Konferenzbeitrag
Thulium-based fiber lasers potentially provide for the demand of high average-power ultrafast laser systems operating at an emission wavelength around 2 μm. In this work we use a Tm-doped photonic-crystal fiber (PCF) with a mode field diameter of 36 μm enabling high peak powers without the onset of detrimental nonlinear effects. For the first time a Tmdoped PCF amplifier allows for a pump-power limited average output power of 241 W with a slope efficiency above 50\%, good beam quality and linear polarization. A record compressed average power of 152 W and a pulse peak power of more than 4 MW at sub-700 fs pulse duration are enabled by dielectric gratings with diffraction efficiencies higher than 98\% leading to a total compression efficiency of more than 70\%. A further increase of pulse peak power towards the GW-level is planned by employing Tm-doped large-pitch fibers with mode field diameters well above 50 μm. The coherent combination of ultrafast pulses might eventually lead to kW-level average power and multi-GW peak power.