Fiber Optic Facts
To connect computers using fiber optic cables,
you need two fiber strands. One strand transmits
signals, and the other strand receives signals.
Fiber optic cabling is composed of the following
components:
- The core carries the signal. It is made of plastic or glass.
- The cladding maintains the signal in the center of the core as the cable bends.
- The sheathing protects the cladding and the core.
Fiber optic cabling offers the following advantages and disadvantages:
| Advantages |
- Totally immune to EMI (electromagnetic interference)
- Highly resistant to eavesdropping
- Supports extremely high data transmission rates
- Allows greater cable
distances without a repeater
|
| Disadvantages |
- Very expensive
- Difficult to work with
- Special training required to attach connectors to cables
|
Multi-mode and single mode fiber cables are distinct from each other and not
interchangeable. The table below describes multi-mode and single mode fiber
cables.
| Single Mode |
- Transfers data through the core using a single
light ray (the ray is also called a mode)
- The core diameter is around 10 microns
- Supports a large amount of data
- Cable lengths can extend a great distance
|
| Multi-mode |
- Transfers data through the core using multiple light rays
- The core diameter is around 50 to 100 microns
- Cable lengths are limited in distance
|
Fiber optic cabling uses the following connector types:
| Type |
Description |
ST Connector
|
- Used with single and multi-mode cabling
- Keyed, bayonet-type connector
- Also called a push in and twist connector
- Each wire has a separate connector
- Nickel plated with a ceramic ferrule to insure
proper core alignment and prevent light ray
deflection
- As part of the assembly process, it is necessary to polish the
exposed fiber tip to ensure that light is passed on from one cable to
the next with no dispersion
|
SC Connector
|
- Used with single- and multi-mode cabling
- Push on, pull off connector type that uses a locking tab to maintain connection
- Each wire has a separate connector
- Uses a ceramic ferrule to insure proper core
alignment and prevent light ray deflection
- As part of the assembly process, it is necessary to polish the exposed
fiber tip
|
LC Connector
|
- Used with single- and multi-mode cabling
- Composed of a plastic connector with a locking tab, similar to a RJ-45
connector
- A single connector with two ends keeps the
two cables in place
- Uses a ceramic ferrule to insure proper core
alignment and prevent light ray deflection
- Half the size of other fiber-optic connectors
|
MT-RJ Connector
|
- Used with single and multi-mode cabling
- Composed of a plastic connector with a locking tab
- Uses metal guide pins to ensure it is properly aligned
- A single connector with one end holds both
cables
- Uses a ceramic ferrule to insure proper core
alignment and prevent light ray deflection
|
Often you will purchase fiber optic cables
of the correct length and with the requisite
connectors for your application. For long
cable runs between floors or overhead, you
might hire an experienced contractor to install
the cable and the necessary connectors. To
add connectors onto a fiber optic cable requires
some practice.
- Keep the area as clean as possible.
- Cut the cable with a clean 90 degree cut.
- Polish the end of the cable prior to adding
the connector. Use special polishing film
and tools for polishing cable ends.
- Glue or crimp the connector onto the cable.
- Cover or cap any connectors that won't be
hooked up immediately to keep them clean.
- If necessary, you can directly splice two
cable ends together; however, this requires
expensive and specialized equipment.