Title :
Reduction of amplified spontaneous emission from a transmitted soliton signal using a nonlinear amplifying loop mirror and a nonlinear optical loop mirror
Author :
Yamada, Eiichi ; Nakazawa, Masataka
Author_Institution :
Opt. Transmission Line Lab., NTT Telecommun. Field Syst. R&D Center, Ibaraki, Japan
fDate :
8/1/1994 12:00:00 AM
Abstract :
The amplified spontaneous emission (ASE) from concatenated erbium-doped fiber amplifiers (EDFA´s) in a 10 Gb/s 500 km soliton transmission system has been successfully reduced through the use of a nonlinear amplifying-loop mirror (NALM). By using the NALM the ratio of the signal peak to ASE was improved from 17.4:1 to 24.9:1. A similar result was obtained for a nonlinear optical-loop mirror (NOLM) with a 6:4 directional coupler. It is noted that pulse transmission through the NALM or the NOLM gives rise to frequency chirp, which means that these fiber devices are not appropriate for use at the midpoint of a long-distance soliton transmission. The chirp characteristics caused by the NALM were also described and the optimum condition for nonlinear switching was obtained
Keywords :
erbium; fibre lasers; laser accessories; mirrors; optical links; optical solitons; superradiance; 10 Gbit/s; 500 km; amplified spontaneous emission; chirp characteristics; concatenated Er-doped fiber amplifiers; fiber devices; frequency chirp; long-distance soliton transmission; nonlinear amplifying loop mirror; nonlinear optical loop mirror; nonlinear switching; pulse transmission; signal peak; soliton transmission system; transmitted soliton signal; Chirp; Concatenated codes; Erbium-doped fiber amplifier; Fiber nonlinear optics; Mirrors; Nonlinear optical devices; Nonlinear optics; Solitons; Spontaneous emission; Stimulated emission;
Journal_Title :
Quantum Electronics, IEEE Journal of
