I. Introduction
Recent advances in the development of novel fibers such as photonic crystal fibers [1], [2], microstructure fibers, [3] and other highly nonlinear solid-core fibers [4]–[7] have sparked renewed interest in fiber nonlinear optics. These fibers have high nonlinearities due to their small core and, in some cases, material composition [8], [9]. They also have unique dispersion profiles, enabled by the influence of waveguide dispersion balancing that of the material dispersion. These characteristics have allowed nonlinear experiments to be performed with much lower powers than previously possible. Applications include frequency metrology [10], medical imaging [11], spectroscopy [12], characterization of broadband devices such as photonic crystals [13], [14], and communications systems.