High Power Fibre Integrated Sources

This presentation gives an emphasis on the development of all-fiber chirped pulse amplifier (CPA) sources. It describes both Yb and Yb-Er based CPAs, where powers of 20 kW in picosecond pulses recompressed in up to 110 m of air core photonic band gap fibre. The problem of dispersion slope, leading to incomplete recompression of the stretched pulses are also described, as well as the simple compression configuration using high efficiency transmission gratings. In the latter, frequency chirping and simultaneous amplification of a 4 ps pulse from a passively mode locked Yb fibre laser is achieved in a polarization maintaining amplifier and recompressed to obtain peak powers of 270 kW at 2.5 W average power with pulse durations of 140 fs. The limits to further power enhancement set by nonlinearity are also described. Spectral recompression as a result of nonlinearity is also demonstrated. An all fibre integrated scheme where spectral compression factors approaching times twenty have been achieved with watts average power, output pulse durations of ~7 ps and peak powers of 3-5 kW. Other schemes are also described, where transform limited operation may not be needed nor required where peak powers of up to 100 kW can be achieved and average powers up to 15 W, pulse durations selectable between 2-20 ps in a fully integrated system with a 20times30 cm footprint, 5 cm high. This laser scheme has also been applied to integrated supercontinuum generation in the ultraviolet where average powers of up to 5 mW/nm have been achieved