How Fiber Optic Cables Work
The traditional method of data transmission over copper
cables is accomplished by transmitting electrons over
a copper conductor. Fiber Optic cables transmit a digital
signal via pulses of light through a very thin strand
of glass. Fiber strands (the core of the fiber optic
cable) are extremely thin, no thicker than a human hair.
The core is surrounded by a cladding which reflects
the light back into the core and eliminates light from
escaping the cable.
A fiber optic chain works in the following manner.
At the one end, the fiber cable is connected to a transmitter.
The transmitter converts electronic pulses into light
pulses and sends the optical signal through the fiber
cable. At the other end, the fiber cable is plugged
into a receiver which decodes the optical signal back
into digital pulses.
Multimode vs Singlemode Fiber A "mode" in Fiber Optic cable refers to
the path in which light travels. Multimode cables have
a larger core diameter than that of singlemode cables.
This larger core diameter allows multiple pathways and
several wavelengths of light to be transmitted. Singlemode
cables have a smaller core diameter and only allow
a single wavelength and pathway for light to travel.
Multimode fiber is commonly used in patch cable applications
such as fiber to the desktop or patch panel to equipment.
Multimode fiber is available in two sizes, 50 micron
and 62.5 micron. Singlemode fiber is typically used
in network connections over long lengths and is available
in a core diameter of 9 microns (8.3 microns to be exact).
50 micron vs 62.5 micron fiber Both 50 micron and 62.5
micron fiber optic cables use an LED or laser light
source. They are also used in the same networking applications.
The main difference between the two is that 50 micron
fiber can support 3 times the bandwidth of 62.5 micron
fiber. 50 micron fiber also supports longer cable runs
than 62.5 micron cable.
Simplex vs Duplex Cable Simplex cable consists of a single fiber optic strand.
Data is transmitted in only a single direction, transmit
to receive. Duplex cable consists of two fiber optic
strands side-by-side. One strand goes from transmit
to receive and the other strand connects receive to
transmit. This allows bi-directional communication between
devices.
Fiber Optic Connectors There are a variety of fiber optic connectors. Below
is a common list:
ST
SC
LC - Also known as SPF, Small Form Factor & Mini
Gibic
MT-RJ
FC
VF-45
MIC
Advantages & Disadvantages of Fiber Optic cable There are many advantages and disadvantages in using
fiber optic cable instead of copper cable. One advantage
is that fiber cables support longer cable runs than
copper. In addition, data is transmitted at greater
speeds and higher bandwidths than over copper cables.
The major disadvantages of fiber optic cables are cost
and durability. Fiber cables are more expensive than
copper cables and much more delicate.
