| 摘要 |
<p>A Raman-amplified optical transmission system Ä80Ü includes a source of optical transmission signals having a system wavelength, lambda s, that are connected to one end of the of a first optical fiber Ä50-1Ü having a large effective area, i.e., Aeff ≥ 70 mu m<2>. The other end of the first optical fiber is connected to a second optical fiber Ä50-2Ü having a small effective area, i.e., Aeff ≤ 60 mu m<2>. Preferably, the first and second optical fibers have opposite dispersion signs. A wavelength-division multiplexer Ä87Ü, for example, couples optical transmission signals lambda 1... lambda n, from an optical pump Ä88Ü to the second optical fiber that cause it to exhibit stimulated Raman scattering, which provides amplification of the optical transmission signals. Preferably, the optical pump signals propagate along the second optical fiber in a direction that is opposite the direction of the optical transmission signals. Exemplary cables Ä500, 600Ü are disclosed that include both large and small-effective-area fibers. One cable Ä600Ü is defined by a planar array of optical fibers that are bound together by a matrix material Ä65Ü in what is referred to as a ribbon, and another cable Ä500Ü is defined by fibers that are enclosed within one or more plastic tubes Ä52Ü. <IMAGE> <IMAGE></p> |
