Ultra-multiplexing transmission in high-speed optical land cables with reduction of four-wave mixing

Ultra-high speed optical land cables of ultra-product (capacity*repeater spacing) in advanced optical communication systems are electro-optically designed over wide ranges of the affecting parameters. Reduction of four-wave mixing is processed. Soliton transmission technique is employed through two ultra multiplexing techniques (200 links (UW-SDM) plus 4000 channels (UW-WDM) over optical window of special interest from 1.45 /spl mu/m up to 1.65 /spl mu/m. The employed optical window of 200 nm is suggested due to the maximum ability of amplifiers. The chromatic dispersion is squeezed at any desired value. Different links in such cable are designed at different thermal fields. The spaced multiplexed links are equally distributed over minor inner cores in the major cable. Each link has its design parameters (the percentage of germania, the relative refractive index difference, and the central wavelength of sub-optical window). It is found that the maximization of the product of transmitted bit rate and the repeater spacing assures the need of ultra-multiplexing; there are positive correlations for either the spectral losses or the total chromatic dispersion and the thermal environmental conditions; after installation, the thermal variations at different cable locations create severe reductions in both the transmitted bit rate and the repeater spacing; negative thermal sensitivities are found (as /spl Delta/T = /spl plusmn/ve, /spl Delta/B/sub T/ = /spl mnplus/ve, and /spl Delta/R/sub s/ = /spl mnplus/ve); higher repeater spacing, higher products, and higher bit rates are obtained at lower squeezed dispersions at any temperature; and the same sorts of variations as in v are obtained as the number of links increases; each link must possesses special design parameters to yield the same squeezed chromatic dispersion. These design parameters are the germania percentage and the relative refractive index difference.