The interface types of fiber optic patch cords are typically divided into three categories: PC (Physical Contact), APC (Angled Physical Contact), and UPC (Ultra Physical Contact). They differ slightly in the design and processing of the fiber optic connector end faces, which affect the performance and characteristics of the connection.
Different end face grinding angles: PC (Physical Contact) connectors have a spherical surface grinding polish, where the fiber end face is polished into a slight spherical shape to reduce the air gap between fiber components, achieving physical contact between two fiber end faces. UPC (Ultra Physical Contact) connectors feature a slightly curved end face to achieve more precise alignment. UPC optimizes end face polishing and surface cleanliness based on PC, resulting in a dome-shaped appearance.
Different colors: APC connectors are typically green, while UPC/PC connectors are blue.
Optical inspection standards: Different grinding methods affect fiber transmission quality, mainly reflected in return loss and insertion loss. Insertion loss refers to the signal loss caused by connectors or cables, with PC, UPC, and APC connectors typically having an insertion loss of less than 0.3dB. Return loss indicates signal reflection performance, usually represented by negative dB values, where higher values are better. APC connectors usually exhibit superior return loss compared to UPC connectors, typically reaching -65dB.
Application scenarios: PC is the most common grinding method for fiber optic connectors in patch cords, widely used in telecommunications carrier equipment. UPC is commonly used in Ethernet network devices (such as ODF fiber distribution frames, media converters, and fiber switches), digital, cable TV, and telephone systems, among others. APC is generally used in high-wavelength range optical RF applications such as CATV, as well as in passive optical applications like PON network structures or passive optical LANs.
In summary, PC, APC, and UPC are common interface types for fiber optic patch cords. They differ slightly in end-face design and processing methods, suitable for different application scenarios. Users can choose the appropriate interface type based on specific requirements.
