Femtosecond Pulse Propagation in Erbium-Doped Single-Mode Fibers

Abstract

Nonlinear pulse propagation and amplification in Erbium doped fibers (EDF) has arisen considerable attention [1-3]. Pulse propagation without amplification can be affected not only by nonlinear mechanisms such as self-phase modulation (SPM) and intrapulse stimulated Raman scattering (ISRS) [4], but also can be influenced by the dopant susceptibility [2,3]. Recently Zhu and Sibbett [3] described results of pulse propagation in EDF in the femtosecond regime, without amplification, but the observed spectral and temporal features have not been fully explained. In this communication, we report on a similar experiment which is further supported by numerical simulations. Pulses with 130fs centered at 1515nm, were generated with a time-bandwidth product of 0.45 through a soliton-Raman process in an optical fiber (minimum dispersion was at 1360nm) pumped at 1320nm with a Nd : YAG laser [5]. The pulses were launched through 3m of EDF (core diameter: 6.5µm, Er concentration of ~ 0.01M). The output spectrum and autocorrelation of the pulses are shown in fig. 1(a-c) for two different incident peak powers.