Fiber Optic Connector Type PC

PC (Physical Contact) fiber optic connectors are polished to allow direct contact between fiber end faces, reducing air gaps but offering moderate return loss compared to newer UPC and APC connectors.

Overview of PC Connectors

A P

C connector stands for Physical Contact fiber connector, designed so that the end faces of two fibers touch directly, minimizing the air gap between them and improving light transmission efficiency. The fiber end face is slightly convex, appearing almost flat due to a large radius of curvature, with the optical fiber core at the highest point to ensure physical contact. This design reduces signal reflection but provides a return loss of around -40 dB, which is higher than UPC (-50 dB) and APC (-60 dB) connectors.

Comparison with Other Polish TypesUPC (Ultra Physical Contact): An improved version of PC with a more pronounced dome-shaped end face, offering better surface finish and lower return loss (~-50 dB). Suitable for most digital and analog transmission systems.

AP

C (Angled Physical Contact): Features an 8° angled ferrule end face, significantly reducing back-reflection and achieving return loss around -60 dB. Ideal for high-frequency RF, CATV, and satellite applications. ApplicationsPC connectors were widely used in OM1 and OM2 multimode fibers and early single-mode networks.

While largely replaced by UPC and APC connectors in modern high-performance systems, PC connectors may still be found in legacy networks or cost-sensitive applications where moderate return loss is acceptable.

Key Points

Polish Style: Slightly convex, physical contact end face. Return Loss: Approximately -40 dB. Advantages: Simple design, reduces air gaps, easy to manufacture.

Limitations: Higher back-reflection compared to UPC and APC, less suitable for high-speed or high-frequency applications. Connector Forms: Can be applied to SC, LC, ST, and FC connector types. In summary, PC connectors are the original physical contact fiber connectors, providing direct fiber-to-fiber contact with moderate performance.

They have been largely superseded by UPC and APC connectors for applications requiring lower return loss and higher signal fidelity.