Extension of the Transmission Length of Optical FDM System by using Distributed In-Line Group-Delay Equalizers

Abstract

Optical frequency division multiplexing (FDM) transmission systems are promising to realize the large capacity. In such optical FDM transmission systems, the fourwave-mixing (FWM) occurs as a serious limiting factor. The FWM can be suppressed by the fiber dispersion, however, which must be compensated by the group-delay equalizers.In this paper, an optical FDM transmission system of equally spaced channels with the distributed in-line group-delay equalizers is proposed and evaluated by the computer simulations. The simulations show that in the optical FDM transmission system with the distributed in-line equalizers, both the FWM and the random interaction between the fiber dispersion and the XPM/SPM can be suppressed effectively. Consequently, the system makes the transmission length about 2.2 times longer than that of the systems with one receiving-end equalizer. Moreover, among the methods for realizing the middle-haul and large capacity systems, the optical FDM transmission system with the distributed in-line equalizers has been confirmed to be most promising.