Experimental demonstration of ±π/2-phase-shifted SSFBG encoder for security improvement in time-spreading OCDMA

We experimentally demonstrate the security improvement using ±π/2-phase-shifted SSFBG encoder in time-spreading OCDMA. Compared with conventional 0/π-phase-shifted SSFBG encoder, ±π/2-phase-shifted SSFBG encoder conceals code pattern well in the encoded waveform. We also investigate the influence of input pulse and the experimental measurement matches the calculated result very well.