Ultra high purity optical fiber communications was first successfully used in Japan in the development of the public communications network in September 1980 (Showa 55). Five years later, in February 1985 (Showa 60), the Japan end-to-end optical fiber cable route was completed. The cable ran from Asahikawa in Hokkaido to Kagoshima in Kyushu, linking the main cities along the Pacific coast (total length 41,000km). High frequency digital signals sent over optical fiber could travel more than 80km without amplification. Optical fiber can thus provide highly reliable communications and is not affected by problems such as crosstalk and electromagnetic induction.

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