Ultrashort pulse propagation in air-silica microstructure fiber.

The unique dispersive and nonlinear properties of air-silica microstructure fibers lead to supercontinuum generation at modest pulse energies. We report the results of a comprehensive experimental and numerical study of the initial stages of supercontinuum generation. The influence of initial peak power on the development of a Raman soliton is quantified. The role of dispersion on the spectral development within this pre-supercontinuum regime is determined by varying the excitation wavelength near the zero dispersion point. Good agreement is obtained between the experiments and simulations, which reveal that intrapulse Raman scattering and anti-Stokes generation occur for low power and short propagation distance.