Mixed data rate and format transmission (40-Gbit/s non-return-to-zero, 40-Gbit/s duobinary, and 10-Gbit/s non-return-to-zero) by mid-link spectral inversion

A polarization-diverse subsystem based on periodically poled lithium niobate waveguides is used as an optical phase conjugator for compensation for linear and nonlinear distortion. We show successful transmission formats of 13×40 Gbit/s non-return-to-zero mixed with 6×10 Gbit/s non-return-to-zero and 40-Gbit/s duobinary over 8×100 km of standard single-mode fiber. A single phase conjugator is used to conjugate all data formats, including the alternative duobinary format, simultaneously.