Light work for submarine cables

EE 64 March 1986 Light work for submarine cables by Kenneth Fitchew, British Telecom Research Laboratories, Martlesham Heath, Ipswich Submarine cab/es have entered a new era with the application of optical technology, making them compatible with digital networks ashore. During 1985 the worlds first international optical- fibre submarine cable was laid between the UK and Belgium, bringing a new economy to this means of international communication. It is well over 100 years since the first submarine telecommunications cables were laid. The Atlantic Ocean was spanned successfully in 1866, an event that opened the first age of submarine cables, the telegraph cables. They were simply insulated con- ductors; on long routes they caused a great deal of attenuation and distor- tion of signals at even very low frequencies, so they could be used only for low-speed telegraph signals. And their gutfa- percha insulation was often attacked by teredo worms. The development of the thermionic valve...