Bit-error-rate improvement of binary phase-shift keying signals with an optoelectronic regenerator based on the feed-forward control of a LiNbO3 intensity modulator

This study evaluates the performance of an optoelectronic regenerator based on feed-forward control of a LiNbO3 intensity modulator for optical binary phase-shift keying (BPSK) signals. First, in order to confirm the operation principle, we measure the transfer function of the regenerator in terms of the optical power, and observe the power limiting effect. Next, we numerically and experimentally evaluate the performance of the regenerator for 10-Gbit/s optical BPSK signals where BER is measured for various receiver OSNR. We obtain a received power improvement of approximately 1 dB at a bit error rate of 10−4. Finally, we compare the regenerator performance for BPSK signals with that for differential phase-shift keying (DPSK) signals by calculating the BERs with offline digital signal processor for identical experimental data. It is shown that the regenerator is more effective for BPSK signals than for DPSK signals because DPSK signals are more fragile against phase fluctuation that cannot be suppressed by our regenerator.