included: using a supercontinua to measure the group velocity dispersion in optical fibres; the demonstration of a 1 Tbit/s based WDM system; and more recently a 1000 channel dense wavelength division multiplexed (DWDM) system capable of 2.8 Tbit/s using a supercontinuum fractionally more than 60 nm wide. The first demonstration of a fibre-based supercontinuum pumped by a fibre-based laser was reported by Chernikov et al. in 1997. They made use of distributed back-scattering to achieve passive Q-switching in single-mode ytterbium and erbium-doped fibres. The passive Q-switching produced pulses with a 10 kW peak power and a 2 ns duration. The resulting continuum stretched from 1 μm to the edge of the silica window at 2.3 μm. The first three Stokes lines were visible and the continuum stretched down to about 0.7 μm but at significantly reduced power levels. Progress since 2000 Advances made during the 1980s meant that it had become clear that to get the broadest continua in fibre, it was most efficient to pump in the anomalous dispersion regime. However it was difficult to capitalise upon this with high power 1 μm lasers as it had proven extremely difficult to achieve a zero dispersion wavelength of much less than 1.3 μm in conventional silica fibre. A solution appeared with the invention of Photonic-crystal fibers (PCF) in 1996 by Knight et al. The properties of PCFs are discussed in detail elsewhere, but they have two properties which make PCF an excellent medium for supercontinuum generation, namely: high nonlinearity and a customisable zero dispersion wavelength. Amongst the first was Ranka et al. in 2000, who used a 75 cm PCF with a zero dispersion at 767 nm and a 1.7 μm core diameter. They pumped the fibre with 100 fs, 800 pJ pulses at 790 nm to produce a flat continuum from between 400 and 1450 nm. This work was followed by others pumping short lengths of PCF with zero dispersions around 800 nm with high power femtosecond Ti:sapphire lasers. Lehtonen et al. studied the effect of polarization on the formation of the continua in a birefringent PCF, as well as varying the pump wavelength (728-810 nm) and pulse duration (70-300 fs). They found that the best continua were formed just inside the anomalous region with 300 fs pulses. Shorter pulses resulted in clear separation of the solitons which were visible in the spectral output. Herrmann et al. provided a