Inter-Band Crosstalk Reduction Using Sinc Apodization of Super-Structured Fiber Bragg Gratings for Hybrid WDM/OCDM Add/Drop Filters

Here, we propose a newly developed hybrid system of wavelength-division multiplexing (WDM) and optical code-division multiplexing (OCDM) with phase-shifted coherent time-spreading for the future metro-access integrated network. In order to suppress the inter-band crosstalk from the WDM interfering channels, the sinc-apodizing technique is proposed for the super-structured fiber Bragg gratings (SSFBGs) as the add/drop filters. The suppression of crosstalk is demonstrated by two-channel WDM and OCDM experiments, compared with conventional SSFBGs with uniform index profile. The proposed method suppresses the crosstalk and shows the feasibility of the 160 (10 WDM 16 OCDM)-channel system.