Page 30 - Optical Switching And Networking Handbook

Introduction to Optical Communications 15

jacket
Figure 1-8
Light travels glass cladding
down the glass.

point
glass
light core
source

glass cladding

jacket
Source: Corning

fiber, the light reaches the outside edge of the core. Normally, it
would simply exit the fiber at this point, but this is where the
cladding helps. When the light hits the cladding (which is made of a
material selected especially because it reacts differently to light than
the core material), instead of going on straight, it reflects. This cre-
ates a tunnel effect in which the light bounces its way down the fiber
until it exits at the other end of the fiber.

Facts about Fiberoptics

Everyone has a story to tell when asked about fiber. Many of the
myths and facts get confused and confusing. Thus we should under-
stand just why everyone is so excited about the use of fiberoptics.
Let’s start with the facts first:
1. Optical fiber will be the backbone of the information
superhighway, transporting voice, video, and data to businesses,
schools, hospitals, and homes. Demands for information continue to
increase so much that the maximum available transport rates are
doubling approximately every two years. Because of this rapid
growth, electronic functions in communications networks eventually
will be replaced by photonic functions, which provide higher
information-carrying capacity.