Spectral coded phase bipolar OCDMA technological implementation thanks to low index modulation filters

Optical code division multiple access (OCDMA) systems are attracting an increasing interest in optical fiber communication. This is due to the various advantages that they provide; in particular for the simultaneous improvement capacity and flexible channel allocation as well as fastest data speeds and increased security. In this paper, the authors present an experimental demonstration of bipolar optical CDMA System with phase shift using E-beam technique on H_xLi_{1 - x}NbO₃ transmission channel realized by proton exchange. The idea of the proposed system is to evaluate the result of eight cascaded Bragg filters in very narrow band. The coded sequence corresponds to that of Hadamard H₈(7) , represented by the bits ’1 1 −1 −1 −1 −1 1 1’, and phase shift have been identified on the coder spectral response whilst increasing the multiplexing capacity in terms of the total number of users and the data.