Abstract

We study the generation of femtosecond supercontinua in highly nonlinear fibers (HNLFs) pumped at a central wavelength of 1.55 μm. Details of experimental spectra ranging from 950 nm to 2400 nm [1] are theoretically simulated quantitatively. We obtain a precise understanding of the nonlinear interactions in the time and frequency domains. Pump pulse characteristics determined via FROG and broadband measurements of fiber dispersion profiles enter the calculations. Excellent agreement between simulated and measured data using an amplified femtosecond Enfiber laser as a pump is demonstrated in Figs. 1 (a) and (b). The simulation model is based on a nonlinear propagation equation including the instantaneous Kerr nonlinearity and the retarded Raman response of the fiber. Numerical integration is performed via a symmetric split-step Fourier method. Special attention is paid to the nonlinear convolution integral of the Raman part.

© 2007 IEEE