Improving soliton transmission by optical phase conjugation

The optical phase conjugation (OPC) has been proposed to compensate for the chromatic dispersion to improve the bit rate of the optical transmission 1 Recently, the OPC is demonstrated to improve the bit rate of the transmission of the 1.55 m signal in the standard fiber with the loss compensated by the erbium—doped fiber amplifiers.23 This technique in fact can also be applied to improve the performance of the soliton transmission 4 .5 Large separation between neighboring solitons is required to avoid the nonlinear interaction between them. On the other hand, the transmission distance is limited by the timing jitter of the soliton caused by the amplified spontaneous emission noise (ASEN) introduced by the optical amplifier, which randomly modulates the carrier frequency of the soliton. This is known as the Gordon—Haus effect.6 In this paper, we will numerically show that they can be reduced by the OPC and discuss the criteria for applying the conjugators.