Chromatic-dispersion-free transmission using time-reversal optical parametric amplifier

A chromatic-dispersion-free transmission using a time-reversal optical parametric amplifier (OPA) for 10 Gbit/s data over 25 km of standard single-mode fibre is demonstrated. The time-reversal was achieved using optical phase conjugation in the OPA. A pilot signal was first sent to estimate the optical channel, which would be reshaped by the OPA and then retransmitted with data through the same fibre. The dispersion is compensated automatically through the transmission. Experimental results showed that around 1 dB improvement can be obtained at a bit error rate of <;10^-9 compared to the traditional return-to-zero on-off keying link.