The kink protection hood helps to make sure that the cable leaves the jack within a specified radius in order to keep the stress on the fibres at a minimum to prevent damage.
The cover is made of metal or plastic. It contains the ferrule and the strain relief for the cable within the connector. Always grab the cover of the plug when handling.
The ferrule is usually made of ceramic, sometimes of plastic or metal. It is used to centre the fibre strand within the plug. The fibre is glued into the central drill hole. The fibre is brought to the tip of the ferrule where it is polished flat. This is the surface where the light signal is transferred.
PC - Physical Contact
The connectors exert pressure on one another when connected. The ferrule is polished flat at a 90° angle.
APC - Angles Physical Contact
In this case, the connectors also exert pressure on one another when connected. However, the ferrule is polished at a tilted angle. This minimises return loss.
The ISO/IEC 60874-19-1 standard for FO connectors recommends the following colour coding:
• Multimode: beige or black
• Singlemode (PC): blue
• Singlemode (APC): green
How to recognise them: A member of the family of small format connectors since it only takes up half the space of an SC connector. Its ferrule is also considerably smaller. This connector is also available in duplex version (2 connectors joined together). It is used more and more often in multimode and single mode applications
