What are the key differences between PC, UPC, and APC fiber connector polishes?Updated 9 months ago

PC (Physical Contact), UPC (Ultra Physical Contact), and APC (Angled Physical Contact) differ primarily in their end-face polish, affecting reflectance. PC has a slight curve to reduce air gaps, UPC further refines this surface for lower back reflection, and APC adds an 8-degree angle for the tightest connection and least reflectance.

Why is reflectance important in choosing a fiber connector polish?

Reflectance, or optical return loss, is crucial as it represents the light reflected back to the source. Lower reflectance (higher negative dB value) indicates better performance. High reflectance can cause signal loss and degradation, particularly in high-precision applications like video applications where low reflectance is very important.

Can APC connectors be used interchangeably with PC and UPC connectors?

No, APC connectors are not interchangeable with PC and UPC connectors due to their unique angled end-face. Mating an APC connector with non-APC types can lead to significant return loss and data issues. APC must be mated with APC connectors.

How can I distinguish between singlemode UPC and APC connectors?

The color of the connector body is the key. Singlemode UPC connectors have a blue body, while APC connectors are green. This color coding helps easily differentiate between the two, especially since the connector ferrules are small and hard to distinguish.

Should I choose UPC or APC polish for my fiber connection needs?

The choice depends on your application requirements. UPC is common and suitable for both multimode and singlemode, offering reliable performance for less sensitive systems. APC, used only for singlemode, is ideal for high-precision optical fiber signaling, such as in high-speed networks and applications requiring low return loss.

Check out our Cable Academy blog PC vs UPC vs APC Fiber Connectors – What is the Difference? to learn more!