Fiber optics use thin strands of glass called optical fibers to transmit light signals over long distances. Optical fibers have a core that carries the light and a cladding layer that reflects the light down the core. There are two main types: single-mode fibers that carry infrared laser light and multi-mode fibers that carry infrared LED light. A fiber-optic system includes a transmitter that produces light signals, optical fibers that conduct the signals, optional optical regenerators that boost weak signals, and receivers that decode the light signals back into electrical signals. Fiber optics have advantages over copper wire like being thinner, having higher data capacity, less signal degradation, and lower power requirements to transmit signals over long distances.

1. 2.What are Fiber Optics?
・Feature
Made by pure glass, which is very thin as long as a human hair.
It called optical cable, it transmit light signals over long distance.
・Contexture
Core - Thin glass center of the fiber where the light travels
Cladding - Outer optical material surrounding the core that
reflects the light back into the core
Buffer coating - Plastic coating that protects the fiber from
outside
・Type
Single-mode fibers - have small cores and transmit infrared laser
light
Multi-mode fibers - have larger cores and transmit infrared light
of LED

2. 4.A Fiber-Optic Relay System?
・Device to communicate
(1)Transmitter-Produces and encodes the light signals.
It receives and directs the optical device to turn the light
"on" and "off", and then it produces a light signal.
(2)Optical fiber - Conducts the light signals over a distance.
It is core communicate device.
(3)Optical regenerator - May be necessary to boost the light
signal.
It produces a new stronger light signal. This device task is a
laser amplifier for the incoming signal.
(4)Optical receiver - Receives and decodes the light signals.
It gets the incoming digital light signals, and then decodes
them. They are sends the electrical signals to the various
equipment, such as computer, TV or telephone.

3. 5.How Fiber Optics Work
・Advantages points – compared to copper wire
(1) Less expensive (5) Light signals
Cheaper than copper wire. Optical fibers are not interfered
from other fibers.
(2) Thinner
(6) Low power
Smaller diameters than
Optical fibers uses lower-power
copper wire.
transmitters.
(3) High carrying capacity (7) Digital signals
Optical fibers cab be bundled Optical fibers are suited to
fibers than copper wire. carry digital information over
(4) Less signal degradation internet.
The loss signal is less than in (8) Non-flammable
copper wire. No electricity, therefore is not
caused fire hazard.
These are only part, more points exist.