Fiber optics are thin strands of glass that transmit light signals over long distances. Light travels through the core of the fiber by constantly bouncing off the cladding layer via total internal reflection. Fiber optic cables have advantages over copper wire as they can transmit more data signals while being thinner, lighter, and less expensive to produce and maintain.

1. What are Fiber Optics?
Fiber optics are long, thin strands of very pure
glass. The strands are as fine human hair. They
are arranged in bundles called optical fiber
cables. And they used to transmit light signals
over long distances. The core is thin glass center
of the fiber that is to travel light. And the buffer
coating is plastic coating that protects the fiber
from damage, for example, electrical damage,
moisture damage and so on.

2. How Does an Optical
Fiber Transmit Light?
The light in a fiber-optic cable travels through
the core by constantly bouncing from the
cladding, a principle. It was called total internal
reflection. The light wave can travel great
distances because the cladding does not absorb
any light from the core. However, some of the
light signal degrades within the fiber by
impurities in the glass.

3. A Fiber-Optic Relay System
It is easy to understand how optical fibers are
used in communications system, if you image
two naval ships in a fleet need to communicate.
The sailor translates the message into Morse
code and uses a signal light in order to send the
message to the other ship. The fiber-optic relay
system are like this communication.

4. Advantages of Fiber Optics
Several miles of optical cable are able to be
made cheaper than equivalent lengths of copper
wire. And optical fibers are able to be drawn to
smaller diameters than copper wire. More fibers
can be bundled into a given-diameter cable than
copper wires because optical fibers are thinner
than copper wires. Fiber optics are more
advantaged than copper wire like those.

5. How Are Optical Fibers
Made?
Optical fibers are made of extremely pure optical
glass and cladding. The glass in an optical fiber
and glass in window looks like same, but the
thicker the glass gets, the less transparent it
becomes due to impurities in the glass. However,
the glass in an optical fiber has far fewer
impurities than glass in window.

6. Physics of Total Internal
Reflection
Optical fibers are using technology of total
internal reflection. And they have core and
cladding in order to reflect light in optical fiber.
In fiber optics, the critical angle is 90 degrees,
and the light wave angle is less than 90 degrees.
Therefore, light in optical fiber do total internal
reflection. The light waves in optical fibers can
travel great distances by this.