Design of FBG En/Decoders in Coherent 2-D Time-Wavelength OCDMA Systems

A novel fiber Bragg grating (FBG)-based en/decoder for the two-dimensional (2-D) time-spreading wavelength-hopping optical coding is proposed. Compared with other 2-D en/decoders, the proposed en/decoding for an optical code-division multiple-access (OCDMA) system uses a single phase-encoded FBG and coherent en/decoding. Furthermore, combined with reconstruction-equivalent-chirp technology, such en/decoders can be realized with a conventional simple fabrication setup. Experimental results of such en/decoders and the corresponding system test at a data rate of 5 Gb/s demonstrate that this kind of 2-D FBG-based en/decoders could improve the performances of OCDMA systems.