Introduction to Fiber Optic Connector Types and Differences.
PC, UPC, and APC are different polishing styles of the internal ferrule of fiber optic connectors, aimed at improving the efficiency of light transmission between connectors. When a fiber optic connector is inserted into a light source or receiver, light reflects on the surface inside the connector. The various polishing styles can affect the degree of light reflection, thereby impacting the quality of signal transmission.
Differences between PC, UPC, and APC:
Appearance: The main difference in appearance lies in the cross-section of the ferrule. PC and UPC connectors, after polishing, have no angles, but UPC end-faces have slight curvature, while APC has a distinct angled end-face. Additionally, connector color is another distinguishing factor. Typically, blue indicates UPC, while green signifies APC.
Performance and Applications
PC (Physical Contact) Polishing: PC polishing is achieved by applying a slight angle to the connector end-face. This angled design reduces reflection and loss, thereby enhancing the efficiency of light signal transmission. PC polishing is the most common type and is often used in data communication and telephone systems.
UPC (Ultra Physical Contact) Polishing: Compared to PC polishing, UPC polishing is finer, resulting in a smoother surface. By utilizing higher quality polishing techniques, UPC connectors offer lower insertion loss and higher return loss. UPC connectors are typically used in applications such as digital video, CATV, and telephone systems that demand higher optical performance.
APC (Angled Physical Contact) Polishing: APC polishing involves applying a small angle (typically 8°) to the connector end-face. This angled design minimizes back reflections of light, dispersing them away from the light source direction. APC connectors are commonly employed in applications requiring extremely low return loss, such as FTTx and radio frequency (RF) applications.
When selecting the appropriate polishing type for fiber optic connectors, there is no one-size-fits-all answer. Factors such as cost and ease of use should be considered when choosing for specific applications. For applications requiring high precision fiber optic signal transmission, APC connectors are preferred, while for less sensitive digital systems, either PC or UPC connectors may suffice.
These different polishing styles cater to various requirements in optical performance, ensuring optimal signal transmission in diverse applications.