10-Gb/s temporally coded optical CDMA system using bipolar modulation/balanced detection

This study proposes and experimentally demonstrates a 10-Gb/s temporally coded optical code-division multiple-access system using bipolar modulation/balanced detection. For a proof-of-principle, two channels are constructed using one-stage ladder network. The interference noise channel is removed completely after balanced detection. It is shown that the proposed scheme has twice the eye opening compared with the system using single polarity. This increased eye opening can improve a receiver sensitivity by 3.7 dB at a bit-error rate of 10/sup -9/.