Page 29 - Optical Switching And Networking Handbook

14 Chapter 1

Speed of transmission Fiberoptic networks operate at
speeds up to 10 Gbps, as opposed to 1.54 megabits per
second (Mbps) for copper. Soon, a fiberoptic system will be
able to transmit the equivalent of an entire encyclopedia of
information in 1 second. Fiber can carry information so fast
that you could transmit three television episodes in 1
second.
Immunity to electrical and radiofrequency
interference Fiberoptic cables have a greater resistance to
electromagnetic noise from items such as radios, motors, or
other nearby cables. Because optical fibers carry beams of
light, they are free of electrical noise and interference.
Less weight in installation Fiberoptics have a greater
capacity for information, which means that smaller cables
can be used. An optical fiber cable the size of an electrical
cord can replace a copper cable hundreds of times thicker.

How It Works

A glass tunnel through which light travels is created.When the light
hits the cladding, it interacts with and reflects back into the
core. Because of this design, the light can “bend” around curves in
the fiber, and this makes it possible for the light to travel
greater distances without having to be repeated. This is illustrated
in Figure 1-8.
The light that travels along the fiber is made up of a binary code
that pulses “on” and “off” and determines what information a given
signal contains.The advantage of fiber is that these on/off pulses can
be translated to video, computer, or voice data depending on the type
of transmitter and receiver used.
A fiberoptic cable has two parts: the core (center or inside) and a
cladding (outside covering). These two parts of the fiber work
together to cause something called total internal reflection, which is
the key to fiberoptics. The light beam is focused on the core of the
fiber, and it begins its journey down the fiber. Soon, because of a turn
in the fiber or the direction at which the light originally entered the