PC UPC APC

Usually we hear about descriptions like’LC/UPC multi mode duplex fiber optic patch cord 3 meters”, or“FC/APC single mode fiber optic pigtails”,”ST/PC multi mode duplex fiber optic jumper”, what do these words PC, UPC, APC mean? Here we give the explanations.
As we know, fiber optic cable assemblies are mainly with connectors and cables, so the fiber cable assembly names is related to the connector names, we call it LC fiber patch cord, because it is with LC fiber connector, here the words PC, UPC, APC also are related only to the fiber optic connectors and has nothing to do with fiber optic cables.
We have known that PC, UPC, APC is standard of the fiber optic connectors, PC, UPC, APC are short for: Physical Contact (PC),Ultra Physical Contact (UPC), and Angled Physical Contact (APC), they are actually the polish style of fiber optic ferrules. Below is a picture of the fiber optic ferrules. Unlike copper cables with copper thread in the connectors as connection media, fiber optic connectors are with these ceramic ferrules for connection, and different fiber optic connectors the ferrule size and length and
polish styles are different, as can be seen on the picture. Such ferrules is inside the fiber optic connectors and with fiber glass from the fiber optic cable to plug into the ferrule for linking.
The different polish of the fiber optic connector ferrules result in different performance of them, mainly on the back reflection (return loss),.Generally, PC type is required at least 40dB return loss or higher, UPC is 50dB or higher, APC is 60dB or higher. (As we know, the higher the return loss the better the performance). Insertion loss of them all should be less than at least 0.3dB, the lower the insertion loss the better the performance. Single mode fiber optic cables can be with PC, UPC or APC polished connectors, while multimode there is no APC ones.
Our fiber optic patch cord and fiber optic cable assemblies are fully compliant or exceed the industry standards, for example,generally we require all cable assemblies insertion loss 0.2dB max.