Application of VAD Fiber Cable to Commercial Fiber Optic Transmission System (FOTS).

The VAD method for manufacturing graded-index fibers in mass production basis has been successfully developed. The losses of VAD fibers have been reduced to the values mainly determined by Rayleigh scattering loss, as the result of remarkable progress of dehydration technique. At the same time the bandwidths of VAD fibers have been also improved by profile controlling technique. Comparison of the bandwidths measured at plural wavelengths has revealed that the bandwidths of VAD fibers have the upper limts corresponding to theoretical prediction for predict alpha-power profile. Improvement of our cabling techniques has made it possible to manufacture optical fiber cables without impairing intrinsic transmission characteristics of VAD fibers. (Author).