Abstract

Wavelength division multiplexing transports bandwidth in a single fiber in a scalable manner commensurate with the number of wavelengths per fiber. However, each wavelength is sourced by an individual laser as defined by the ITU-T grid. Many individual lasers add to cost and to fault management complexity. Cost sensitive network applications such as metro and point-to-point access require robust and low cost solutions. An alternative to many lasers is a single laser source at higher power which when coupled onto a highly dispersive medium generates a wide spectral band, a supercontinuum, from which a comb of wavelengths can be obtained. In this paper, we develop a supercontinuum model using a single-wavelength laser, a highly nonlinear fiber and a spectrum slicer. We find the acceptable single-wavelength laser power for the optimum (minimum) non-linear fiber length to generate a supercontinuum spectrum with a suitable spectral width and for several center frequencies. A comb generator or spectrum slicer generates optical channels at center wavelengths, channel width and channel separation as recommended by ITU-T standards. We simulate our model for network topologies such as Metro ring, point-to-point and point-to-point with linear add-drop nodes. The OC-48 modulation rate was selected for being the most popular in low cost applications, although our model is suitable to higher rates. We determine the longest link without amplification with performance objective 10^-12 bit error rate. Additionally, we examine the supercontinuum to links with 1+1 and to 1:1 optical channel protection strategies. Our conclusions are supported by simulation results, eye-diagrams, spectrum diagram and BER.

© 2005 Optical Society of America