Supercontinuum generation in photonic crystal fibers with different dispersion profiles

Abstract

It has been investigated of nonlinear propagation of femosecond pulse and supercontinuum generation (SCG) in three photonic crystal fibers (PCFs) with different dispersion profile in the 1550nm window by numerical stimulation. The influence of higher-order effects on supercontinuum, including higher-order dispersion (HOD), self-steepening (SS), and stimulated Raman scattering (SRS), are discussed in detail as well. The results of numerical simulations show that group velocity dispersion and self-phase modulation take main effect in the initial stage. In the PCF with anomalous dispersion, SRS plays main role when the propagation distance increases, which induces a red-shift of the central wavelength, suggesting the appearance of soliton self-frequency shift. In the PCF with near-zero anomalous dispersion, HOD plays main role. This results in the fission of higher-order solitons and remarkable broadening of the pulse spectrum. In the PCF with normal dispersion, higher-order effects have almost no effect on the pulse. The Gaussian pulse wave broadens to rectangular symmetrically, and the pulse spectrum broadens symmetrically, too. However, the broadening is smaller than the former two cases.