FIBRE OPTICAL CONNECTORS
The quality of an optical connector is normally described by two optical parameters:
Insertion loss
Insertion loss means the loss in the transition between two connectors.
Return loss
Return loss describes how much the light reflected back from the connectors is attenuated compared to the light coming in. Return loss is normally not measured for multi mode connectors.
The main connector types are:
- Single mode connectors for telecommunication
- Multi mode connectors for data-communication
- Field connectors for military use
- Special connectors
The connector name is often followed by a suffix like, PC, UPC, SPC or APC. These suffixes indicates how the connectors are polished. The terms PC and APC is relatively unambiguous, but the terms UPC and SPC varies from country to country and should therefore not be used.
SC
LC
E2000
ST
FC
MU
Colors:
Jacket on cords and cables | Connector and Adapter | Description |
Yellow | Blue (PC), Green (APC) | SM, OS2 |
Grey/Slate | Beige | MM, OM1 |
Orange | Beige | MM, OM2 |
Turquoise | Turquoise | MM, OM3 |
Violet | Violet | MM, OM4 |
Lime green | Lime green | MM, OM5 |
PC = ”Physical Contact”. This means that the connector end face is polished with a curvature to achieve physical contact.
APC = ”Angled Physical Contact”. This means that the connector end face is polished with an angled curvature to achieve extra high return loss. Some therefore call them HRL.
APC is not compatible with PC!
Standards for fibre optical connectors
In Europe the IEC standards are normally used, but especially for connectors Telcordia is a standard that often is mentioned. This is an American standard that is used a lot outside Europa.
The standards normally used in USA is TIA/EIA, but they refer to Telcordia for fibre optical connectors.
IEC = International Electrotechnical Commission
TIA = Telecommunications Industry Association
EIA = Electronic Industries Alliance (umbrella organisation for TIA and others)