
Student's
Guide to Information
Technology
Fibre optics
Digital communications, using laser light pulses travelling along thin
optic fibres, are much more efficient than wire communications, for
they allow a very broad bandwidth. This means that they can carry a
large number of telephone calls simultaneously, as well as video
signals and high-volume computer communications.
So to cope with the ever-increasing volume of data communica-
tions of all types, British Telecom is laying optic fibres across the
country to link exchanges. These are strands of
glass,
about 0.1 mm
thick, with walls able to reflect the laser pulses and so prevent them
escaping ...