Design theory of long-distance optical transmission systems using midway optical phase conjugation

This paper describes the basic system principle, the residual waveform distortion, the optimal design method, the ultimate transmission capacity, and its future improvement of the long-distance optical fiber transmission system using midway optical phase conjugation. We show that the periodic power variation in an optical amplifier chain and the dispersion value fluctuation from span to span along the system cause imperfect compensation for waveform distortion in the midway optical phase conjugation system. The optimal design method for suppressing the residual waveform distortion is proposed and confirmed by using computer simulations.