connectors are used to connect two fibers together. When these connectors are
used in a communications system, proper connection becomes a critical factor.
connectors can be damaged by improper cleaning and connection procedures. Dirty
or damaged fiber-optic connectors can result in communication that is not
repeatable or is inaccurate.
connectors differ from electrical or microwave connectors. In a fiber-optic
system, light is transmitted through an extremely small fiber core. Because
fiber cores are often 62.5 microns or less in diameter, and dust particles
range from a tenth of a micron to several microns in diameter, dust and any
contamination at the end of the fiber core can degrade the performance of the
connector interface where the two cores meet. The connector must be precisely
aligned, and the connector interface must be absolutely free of trapped foreign
Connector loss or
insertion loss is a critical performance characteristic of a fiber-optic
connector. Return loss is also an important factor. Return loss specifies the
amount of reflected light; the lower the reflection, the better the connection.
The best physical-contact connectors have return losses greater than -40 dB,
although -20 to -30 dB is more common.
quality depends on two factors: the type of connector and the proper cleaning
and connection techniques. Dirty fiber connectors are a common source of light
loss. Keep the connectors clean at all times, and keep the dust covers
installed when the connectors are not in use.
Before installing any
type of cable or connector, use a lint-free alcohol pad from a cleaning kit to
clean the ferrule, the protective white tube around the fiber, and the end-face
surface of the fiber.
As a general rule,
whenever there is a significant, unexplained loss of light, clean the