100W, single mode, single polarization, picosecond, ytterbium doped fibre MOPA frequency doubled to 530 nm

We have successfully demonstrated a 100W, linearly polarized, near diffraction-limited, 20ps pulse source at 1.06µm based on a fiberised YDFA MOPA seeded by a GS-laser diode. Pulse energies to 0.85µJ and peak powers ≫ 40kW were obtained when operating at a repetition rate of 113.5MHz. Our experimental results show that further power scaling should be possible. Such high average power, single-polarization, near diffraction-limited, ps sources are attractive for high power nonlinear frequency conversion and material processing applications. We have also generated 45W of green light at 530nm at an overall conversion efficiency of 45% by using an LBO crystal. Further power scaling is currently limited by the spectral integrity of the fundamental light. It should be possible to improve the conversion efficiency further by optimizing the final stage amplifier.