Fibre Optics — the Age of the Photon
| Pages | 3-5 |
| DOI | https://doi.org/10.1108/eb057386 |
| Published date | 01 January 1985 |
| Date | 01 January 1985 |
| Author | Alison Calanda |
| Subject Matter | Economics,Information & knowledge management,Management science & operations |
Fibre Optics —
the Age of the
Photon
by Alison Calanda
After many years of inertia, the UK Telecommunications in-
dustry has suddenly sprung to life. The impetus came just
over two years ago when a private-sector company receiv-
ed a 25 year licence to provide Britain with an alternative
communications network. The company, Mercury Com-
munications, is now a wholly-owned subsidiary of Cable &
Wireless, though it was set up jointly with BP. Much of its
future success in the field will depend on its use and
development of the latest telecommunications technology
— fibre optics.
Before the ink on the contract had dried, British Telecom
responded to the prospect of competition by cutting trunk
call charges and announcing advanced digital services for
businesses. Its main union, the POEU (Post Office Engineer-
ing Union), began a campaign of industrial action against
Mercury. Subtler forms of opposition were apparent in the
exceptionally long delays in the provision of private circuits
for Mercury's use. The
lion,
it seemed, would not lie down
quietly.
Mercury took a second look at its forward planning. Swifter,
more reliable and highly competitive means of communica-
tion were needed to attract a wider client range than the
original
plan,
of large businesses only, had intended. So Mer-
cury began wooing the small customer. It extended its
geographic coverage plans and speeded up its technical ex-
pansion.
The race to convert Britain to a new fibre optic net-
work was on.
The principle behind fibre optics is a blindingly simple one.
Pulses of light are beamed down the glass fibre at rates of
up to 2,000 million per second. These pulses contain
cod-
ed information in the binary language of computers — a
pulse for "one" and a gap for "zero". In this way enormous
volumes of computer data or telephone calls can be sent
over distance, transferred by light wave rather than by elec-
tric current. One strand of optical fibre today can carry 250
times the capacity of copper wire. In one second the very
latest lasers can transmit information that conventional
methods take 21 hours to relay.
Understandably
then,
telephone companies all over the
world are rushing to equip their networks with fibre optics
in place of the conventional copper wiring. In France the
DGT (Direction Generale des Telecommunications) joined
the race last year, the US boasts 250,000 miles of network
already laid and predicts that by 1986 they will be installing
1.3 million miles of optical fibre per annum. But it is Japan
which is the leader in the
field.
The giant NTT (Nippon
Telegraph and Telephone) aims to make Japan the first
country in the world to have optical fibres connected to
every home, and plans to spend an estimated 80,000 million
dollars over the next 15 years doing it.
One strand of optical fibre today-
can carry 250 times the capacity
of copper wire
In a sense though, the fibre optic revolution had its beginn-
ings before 1982. Some 30 years ago Charles Kao, then a
young researcher at ITT Corporation in the US, dreamt of
a glass strand which could be used as a pipe to guide light
for communications systems. Others before him had toyed
with the idea of using light to transmit messages, among
them Alexander Graham Bell himself, who as far back as
the 1880s had invented his "photophone" — a machine
which transmitted by focussing light onto a shiny surface
that vibrated in response to sound. The vibrations varied
the intensity of the beams which were then switched to cur-
rent via an intensity-sensitive selenium cell wired across a
battery at the receiver. The current created was amplified
to drive a speaker.
Bell was so excited about his new invention that he decid-
ed to name his daughter after it. Fortunately his decision
was over-ruled and the girl was spared the fate of being
named after a machine that spent the next 100 years of its
life abandoned in a back room of the Smithsonian
Institution.
Bell's machine failed. Its light beam, designed to move
through air, was too easily disturbed by other light sources
and by buildings. It was not until the early 1970s, almost
a full century later, when the Corning Glass Works in New
York produced a light carrying glass fibre of exceptional
puri-
ty, that the idea of fibre optic communication really took off.
The Corning glass fibre was clad in a material of lower reflec-
tive index which prevented light and hence information
"leaking out". In the same year Bell Laboratories tested a
IMDS • JANUARY/FEBRUARY • 1985 3
To continue reading
Request your trial