Reference
Cleaning Connections for Accurate Measurements
Inspecting Connectors
Because fiber-optic connectors are susceptible to damage that is not immediately obvious to the naked eye, bad measurements can be made without the user even being aware of a connector problem. Although microscopic examination and return loss measurements are the best way to ensure good connec- tions, they are not always practical. An awareness of potential problems, along with good cleaning practices, can ensure that optimum connector performance is maintained. With glass-to-glass interfaces, it is clear that any degradation of a ferrule or fiber endface, any stray particles, or finger oil on the endface, can have a significant effect on connector performance. Many times an instrument must be serviced to replace a damaged connector when thousands of dollars and lost time could have been avoided if better care were given to the fiber-optic connector.
Figure 6-3is a close-up micrograph of a clean cable endface. In contrast, Figure 6-4shows a connector endface that was either not cleaned, or not properly cleaned. Material is smeared and ground into the endface causing light scattering and poor reflection. Not only is the precision polish lost, but this action can grind off the glass face and destroy the connector.
Figure 6-3. A clean and problem-free connector