Investigation of nonlinear optical loop mirror based optical thresholding for high speed OCDM system

Abstract

The nonlinear optical loop mirror (NOLM) and the nonlinear amplifying loop mirror (NALM) based optical thresholding in the high speed OCDM system are analyzed, the input pulse peak power of the NOLM is optimized considering the thresholding decision function, pulse shaping and side-lobe suppressing of the NOLM based on high nonlinear fiber (HNLF) are numerically simulated, and theoretical investigation is compared with experimental result. The results show that the interference noise in the 40 Gbit/s OCDM system could be suppressed effectively by the optical thresholding techniques based on the NOLM and the NALM. We show that the NOLM and the NALM can act as a nonlinear processing element capable of reducing both the pedestal associated with conventional matched filtering and the width of the associated code recognition pulse.