All-Fiber Low-Pedestal Spectral Compression in a Novel Architecture Based on an SMF Cascading an HNLF-NOLM

A novel all-fiber low-pedestal spectral compression scheme is proposed and demonstrated. The scheme is based on an anomalously dispersive single-mode fiber (SMF) cascading a nonlinear optical loop mirror with a highly nonlinear fiber (HNLF) in the loop. Both numerical and experimental results show that the spectral pedestal after spectral compression in the HNLF can be efficiently suppressed by the nonlinear optical loop mirror through the chirp-related intensity filtering effect. The measured spectral pedestal energy ratio is 9.59% using the proposed scheme, which is nearly a quarter of that using the conventional alternative based on an anomalously dispersive SMF followed by a feedthrough HNLF.