The simplest way to check for contamination is by disconnecting the fiber connector and holding it under a bright light source. By analyzing the reflection and refraction of light on the end-face, one can determine if the surface is. It's crucial to inspect, clean, and reinspect fiber end faces before mating connectors — whether on patch cords and trunks within the network or on the test reference cord you connect to your tester. In FTTH, ODN, and data center environments, you rely on consistent. The performance of fiber optic patch cords is heavily influenced by the quality of their end-faces. If you look at the connector, the ferrule end face is the exposed white ceramic tip of the fiber cable.