Insertion loss and return loss are an indication of important values to evaluate the quality of fiber optic patch cords, pigtails or connectors termination.
What is Insertion Loss ?
In telecommunications, insertion loss is the loss of signal power resulting from the insertion of a device in a transmission line or in other words Insertion loss refers to the fiber optic light loss caused when a fiber optic component insert into one another to form the fiber optic link.
Absorption, misalignment or air gap between the fiber optic components are the main cause contribution to Insertion Loss.
What is Return Loss ?
In telecommunications, return loss is the loss of power in the signal reflected by a discontinuity in fiber optics (connectors) or in other words Return loss is the fiber optic light gets reflected back at the connection point.
What Does High Return Loss Indicate?
First you will need to perform a visual inspection of the connector ferrule endface
by using either a handheld optical microscope or a fiber optic video probe.
This visual inspection will determine the type of action required to repair the faulty connector. If the connector only has minor damage, (i.e., scratches, small chips, or small pits), then re-polishing the connector will usually fix the problem.
If the visual inspection determines that the connector is shattered or there is no continuity, then a new fiber optic connector must be replaced or terminated.
First you have to locate the damaged location of the fiber optics cable. This can be done either by using a Visual Fault Locator (VFL) or an Optical Time Domain Reflectometer (OTDR).
Based on the location of the fiber cable damage as indicated either or both VFL and OTDR you can decide on a what type of repair required.
The repair might required a fusion splicing between cables, a pigtail assembly, replacement of faulty adapters, macrobending in splicing tray or faulty patchcord due to rodents.
I have been in the field of fiber optics since early 1990s. I gained fiber optics skills and knowledge via my working experience as end-user, main contractor and sub-contractor and finally as an optical fiber enterpreneur.