Distributed mode filtering rod fiber amplifier delivering 292W with improved mode stability

Marko Laurila, Mette M. Jørgensen, Kristian R. Hansen, Thomas T. Alkeskjold, Jes Broeng, Jesper Lægsgaard
2012 Optics Express  
We demonstrate a high power fiber (85μm core) amplifier delivering up to 292Watts of average output power using a mode-locked 30ps source at 1032nm. Utilizing a single mode distributed mode filter bandgap rod fiber, we demonstrate 44% power improvement before the threshold-like onset of mode instabilities by operating the rod fiber in a leaky waveguide regime. We investigate the guiding dynamics of the rod fiber and report a distinct bandgap blue-shifting as function of increased signal power
more » ... ased signal power level. Furthermore, we theoretically analyze the guiding dynamics of the DMF rod fiber and explain the bandgap blue-shifting with thermally induced refractive index change of the refractive index profile.
doi:10.1364/oe.20.005742 pmid:22418380 fatcat:wliqskvdwfa25provwuidfyrue