Photonic band gap fibre compressed chirped-pulse oscillator

One of the most successful techniques for generating highenergy femtosecond laser pulses directly out of an oscillator without external amplification is based on intracavity pulse broadening due to a net positive round-trip group-delay dispersion. The main disadvantage of this concept, however, is the need to have an external compressor, often a pair of prisms separated by an optical path length of several metres. In this paper, we demonstrate for the first time an all-fibre compressor based on a photonic band gap fibre. Compared to a standard prism pair the total length of the set-up can be reduced by up to two orders of magnitude while its throughput is increased at the same time.