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Appendix D - Optical Connector Cleaning
The use of optical fibre connectors requires some care if good results are to be obtained. The core of the
fibre is very small, typically 8 to 9 micrometres in diameter and even the smallest dust particles, lint fibres or
smears of oil can obscure it and cause optical losses. Scratches and chips in the highly-polished end face of
the fibre also result in poor quality, unreliable connections. Therefore, it is important to develop good
habits for handling and cleaning connectors. Ideally, both sides of a connection should be inspected and
cleaned before mating.
Connector tips can easily be damaged by hitting a hard surface. This can be avoided by always keeping the
plastic cover in place when not using or cleaning the connector.
A brief guide to good practise is given here. The interested reader will find further information from Industry
bodies. There are also some useful proprietary standards in the public domain, for example:
•
AT&T: document ID ATT-TP-76461
•
Cisco: document ID 51834
•
JDSU: document ID
IBYC
–
Fiber Inspection, Cleaning & Test
Note: These documents are identified for information only. No connection between any of the named
companies and Smart Fibres Ltd is intended or should be implied.
We understand that the first time user of a Smart Fibres product may not have all the correct equipment to
hand but cleaning and inspection tools are relatively inexpensive and help to ensure continued correct
operation of the interrogator. The regular user should make an effort to acquire them and learn how to use
them effectively. The Interrogator is shipped with a Cletop-S Fibre optic connector cleaner, which facilitates
dry cleaning (see sections 5.1.2 and 5.1.5).
Some or all of the operations described below may be required to ensure that the fibre-optic connection is
free from contaminants. The order of operations is given in Section 0
, ‘Cleaning Flowchart’.
Inspection
It is highly desirable to inspect the end-face of connector ferrules (the white ceramic part) before mating
them, to ensure that they are clean and undamaged. If no inspection means is available, you may skip this
stage and proceed to a dry cleaning step, but be aware of the risk of making lossy connections by mating
ferrules that may be contaminated or scratched.
Remove the protective cap from the connector ferrule. Insert the connector into the fibre inspection
microscope and examine the end face. If the connector is of an angle-polished type, it may be necessary to
rotate it in order to see the end of the fibre clearly. Bulkhead connectors, such as those in the front face of
a Smart Fibres interrogator, can only be inspected using a fibre video microscope with a suitable adapter.
Typical views of a ferrule end-face are shown below:
