High average power supercontinuum generation in photonic crystal fibers

We report on the generation of a high average power, flat supercontinuum using a compact ytterbium-doped fiber amplifier. The femto- and picosecond pulses delivered by the amplifier are coupled into two different photonic crystal fibers. By using picosecond pulses the highest output power of 5 W with a spectrum ranging from below 500 nm up to above 1800 nm is obtained. Numerical simulations are compared with the experimental spectra and it is shown that the main part of the broadening mechanism is a soliton effect even for picosecond pulses. Furthermore, second and third harmonic processes leading to some sharp spectral lines in the visible region are investigated.