Subpicosecond pulse transmission over 144 km using midway optical phase conjugation via a cascaded second-order process in a LiNbO₃ waveguide

We demonstrate for the first time the feasibility of 600-fs pulse transmission over 144 km using midway optical phase conjugation via a cascaded second-order process in a periodically poled LiNbO/sub 3/ waveguide. The output pulses are negligibly distorted and broadened to 680 fs. This result could not be obtained without complete compensation for fourth-order dispersion performed by midway optical phase conjugation.