Causes for increased optical damping:

1. Bending radius too small, kink (e.g. incorrect installation)
   
   
   
2. The covering of the FOC is damaged (e.g. hot parts near the FOC)
   
   
   
3. Scratched end surface (e.g. by improper cutting tool)
   
   
   
4. Soiled end plane (e.g. careless handling)
   
   
   
5. End surfaces lie offset to each other (e.g. incorrect plug connector)
   
   
   
6. End surfaces lie slanted to each other (e.g. damaged plug connector)
   
   
   
7. Gaps between the end surfaces (e.g. due to the plug connector not being engaged)
   
   
   
8. FOC squeezed (e.g. inappropriate crimping)