Intracavity dispersion measurement in modelocked fibre laser

It has previously been shown that the minimum pulse width obtainable in modelocked fibre lasers depends primarily on the total cavity dispersion. The authors compare measurements of the dispersion in figure eight lasers, taken directly by wavelength tuning and indirectly by the sideband spectrum. The dispersions of the different component fibres, including the gain fibre, are deduced from these in situ measurements.