Phase-transparent optical data exchange of 40-Gbit/s DPSK signals using four-wave-mixing in a highly nonlinear fiber

We report the phase-transparent optical data exchange based on non-degenerate FWM in an HNLF via theoretical analysis and experimental verification. 40-Gbit/s NRZ-DPSK data exchange is demonstrated with a power penalty (at 10
^-9
) ~ 4.5 dB.