Agilent Technologies 86038B User Manual page 312

In the case of scratches, or of dust that has been burnt onto the
surface of the connector, you may have no option but to polish
the connector. This depends on the degree of dirtiness, or the
depth of the scratches. This is a difficult procedure and should
only be performed by a skilled person, and as a last resort as it
wears out your connector.
Never look into the end of an optical cable that is connected
W A R N I N G
to an active source.
To assess the projection of the emitted light beam you can use
an infrared sensor card. Hold the card approximately 5 cm from
the output of the connector. The invisible emitted light is
projected onto the card and becomes visible as a small circular
spot.
Cleaning procedure for high-power single mode connections
Optical single mode connectors for high-power applications
(optical power levels bove 100 mW) require careful cleaning to
prevent the power density of burning dust or dirt into the fiber
causing permanent damage to the devices and/or connectors. If
this happens, measurements become inaccurate and
unrepeatable.
The "Preferred Procedure" on page 313 or the "Procedure for
Stubborn Dirt" on page 313 must be strictly followed for each
part of the optical connection (connector, connector interface,
and physical connector interface).
Always make sure that the fiber end-faces are properly cleaned
and unscratched before connection. The fiber end faces must be
visually inspected using a microscope with a magnification of at
leasst 400x. For recommended fiber inspection microscopes,
please refer to personnel in Agilent's Service Team.
The connection should be made immediately after cleaning and
inspection to prevent the connection (connector, connector
interface, and physical connector interface) from becoming
dusty or dirty again.(
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Agilent 86038B Photonic Dispersion and Loss Analyzer, Second Edition