Adva FSP 3000R7 - Cleaning and Inspecting Fibers and Ports

Cleaning and Inspecting Fibers and Ports
Cleaning and Inspecting Fibers and Ports
Perform the procedures in this section to clean and inspect optical cabling and port
connections. Inspection and cleaning are critical and must be performed prior to each
mating.
Risk of equipment damage:
Dirty fiber can impair system performance.
Note
The network fiber and patch panels used to connect ADVA equipment to
the network fiber must have discrete back reflection level values
measured with an optical time-domain reflectometer (OTDR) to be below
-27 dB. For spans using Raman amplifiers, the discrete back reflection
levels are required to be < -32 dB.
Higher back reflection levels may cause BER penalties through in-band
crosstalk generated by multipath interference. The OTDR
measurements need to be taken with a fiber spool having a length
exceeding the OTDR “dead-zone.” One end of the spool is connected to
the OTDR and the other to the patch panel. This ensures reliable back
reflection and loss measurement of the near-end patch panel. OTDR
measurements should be taken in both directions of a fiber.
Quality connections between fiber-optic equipment require clean fiber-optic components.
Cleaning the fiber-optic equipment is one of the most basic and important procedures for
maintaining fiber-optic systems. Any contamination in the fiber connection can cause
failure of the component or failure of the entire system.
Even microscopic dust particles can cause a variety of problems for optical connections.
A particle that partially or completely blocks the core generates strong back reflections,
which can destabilize the laser system. Dust particles trapped between two fiber
endfaces can scratch the glass surfaces. A particle on the cladding or on the edge of the
endface can cause an air gap or a misalignment between the fiber cores, which
significantly degrades the optical signal. You must remove all foreign materials and debris
from the fiber endface before mating the connectors.
Common contaminants include:
• Oils (frequently from human hands)
• Film residues (condensed from vapors in the air)
• Powdery coatings (remaining after water or other solvents evaporate)
If they are not removed, these contaminants can be more difficult to remove than dust
particles and can also cause damage to equipment.
Risk of equipment damage:
With high-powered lasers, such as Raman amplifiers, any contaminant can be
burned into the fiber endface if it blocks the core while the laser is turned on. This
burning may damage the optical surface enough that it cannot be cleaned.
32 FSP 3000R7 Maintenance and Troubleshooting Manual - Product Release 16.2 - Document Issue A