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Home > All Images > 1994 > February > 16 Feb 1994

Images Dated 16th February 1994

Choose from 8 pictures in our Images Dated 16th February 1994 collection for your Wall Art or Photo Gift. All professionally made for Quick Shipping.

Fibre optic cable used for telephones Featured 16 Feb 1994 Image

Fibre optic cable used for telephones

Fibre optic communications. A cable containing optical fibres used to transmit telephone signals. The fibre optic filaments are seen at top right; the rest of the cable is shielding and protective layers. The fibres are made from a special glass which is flexible and has a high refractive index. Each filament is then coated with a protective layer with a low refractive index. A light beam entering the end of the fibre is completely internally reflected at the cylindrical surface of the core. The light may thus travel along the entire cable with little or no absorption. The telephone conversations are carried as pulsed, coded laser signals