Nonlinear propagation of high-power, sub-100-fs pulses near the zero-dispersion wavelength of an optical fiber

The propagation of high-peak-power (>10-kW) sub-100-fs pulses near the zero-dispersion wavelength of an optical fiber was studied experimentally. Four-photon mixing and stimulated Raman scattering were observed for fiber lengths greater than 2 m. With pulses as short as 25 fs, four-photon mixing dominates, resulting in efficient conversion of the input pulse spectrum into two coherent spectral bands. This can be used to extend the useful wavelength range of femtosecond lasers in the infrared.