Constraints on the Design of Ultrahigh-Speed Optical Soliton Communication

Abstract

Almost a quarter of a century have passed since the discovery of optical solitons in fibers. Soliton transmission technology has matured considerably through the use of erbium-doped fiber amplifiers(EDFAs). There are two interesting fields of application for soliton communication. One is long distance transoceanic communication in which the transmission speed is limited to 5–40Gbit/s under the various dispersion and amplifier spacing conditions¹. The other is relatively short distance communication over hundreds kilometer, where the transmission speed is 100Gbit/s-1Tbit/s. This may prove useful as a high speed information highway. Solitons are expected to play a major role both in intercontinental transmission as well as in domestic multimedia transmission. The experiments for the former application have been undertaken by many groups using loop circulation or straight line transmissions. But only a few experiments for the latter have been reported^2,3,4. Kiwatsuki et al. made 80Gbit/s optical soliton trans-mission over 80km with time/polarization domain multiplexed in 1993². Next, single-polarization 80Gbit/s sólito data have been successfully transmitted over 500km in 1994³. And in 1995 time/polarization domain multiplexed 160Gbit/s soliton signals have been transmitted over 200km⁴. Those are important experiments for ultrahigh-speed soliton transmission, which is not as good as a linear system that has already been transmitted at 400Gbit/s over 100km.