II. BASIC PRINCIPLES OF FIBER OPTIC
COMMUNICATION
Fiber optic communication is a communication technology
that uses light pulses to transfer information from one point to
another through an optical fiber. The information transmitted
is essentially digital information generated by telephone
systems, cable television companies, and computer systems.
An optical fiber is a dielectric cylindrical waveguide made
from low-loss materials, usually silicon dioxide. The core of
the waveguide has a refractive index a little higher than that of
the outer medium (cladding), so that light pulses is guided
along the axis of the fiber by total internal reflection [4]. Fiber
optic communication systems consists of an optical transmitter
to convert an electrical signal to an optical signal for
transmission through the optical fiber, a cable containing
several bundles of optical fibers, optical amplifiers to boost
the power of the optical signal, and an optical receiver to
reconvert the received optical signal back to the original
transmitted electrical signal. Figure 1 gives a simplified
description of a basic fiber optic communication system.