Cleaning The Fiber-Optic Connectors - Cisco RFGW-10 Hardware Installation Manual

Cabling the Supervisor Engine
SFP Product Numbers
CWDM-SFP-1590=
CWDM-SFP-1610=

Cleaning the Fiber-Optic Connectors

Fiber-optic connectors are used to connect two fibers together. When these connectors are used in a
communications system, proper connection becomes a critical factor.
Fiber-optic cable 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 inaccurate.
Fiber-optic 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. Therefore, the connector must be precisely aligned, and the connector interface must
be absolutely free of trapped foreign material.
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.
The connection 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 connectors.
Caution
Use extreme care when removing or installing connectors so that you do not damage the connector
housing or scratch the end-face surface of the fiber. Always install protective covers on unused or
disconnected components to prevent contamination. Always clean fiber connectors before installing
them.
To clean the optical connectors, use a CLETOP cassette cleaner (type A for SC connectors or type B for
MT-RJ connectors) and follow the product directions. If a CLETOP cassette cleaner is not available,
follow these steps:
Step 1
Use a lint-free tissue soaked in 99 percent pure isopropyl alcohol to gently wipe the faceplate. Wait five
seconds for the surfaces to dry, and repeat.
Step 2
Remove any residual dust from the faceplate with clean, dry, oil-free compressed air.
Invisible laser radiation may be emitted from disconnected fibers or connectors. Do not stare into
Warning
beams or view directly with optical instruments. Statement 1051
Cisco RF Gateway 10 Hardware Installation Guide
6-28
Wavelength
Longwave 1590 nm laser, single mode
Longwave 1610 nm laser, single mode
Chapter 6 Cabling the Cisco RFGW-10 UEQAM
Color Identifier
Red
Brown
OL-16264-04