PC, UPC and APC are three grinding methods for the inner ferrule of optical fiber connectors. The ferrule of the optical fiber connector is the shell of the bare end of the optical fiber, which is used to connect with the transmitting end or receiving end of another optical fiber. When the connector is installed at the end of the optical fiber, the light will be reflected back to the optical fiber toward the light source, thereby affecting signal transmission. In order to improve the transmission efficiency of optical fibers, engineers introduced ferrule polishing technology.
What is a PC fiber optic connector?
PC optical fiber connector is a connector polished by physical contact, it is the most common type of polishing on OM1 and OM2 multimode fibers. The mating end faces are in physical contact, that is, the end faces are convex arched structures, and the joint cross-section is flat, which is actually micro-spherical grinding and polishing, which is the most widely used in telecom operators' equipment. In the PC fiber connector design, there is a slightly cylindrical tapered head to eliminate the air gap. Therefore, the typical return loss in single-mode fiber applications is about -40dB, which is higher than the original flat polished style. Return loss (-14dB). However, this polishing method of PC connectors has become obsolete and continues to evolve into UPC connectors.
What is UPC fiber optic connector?
UPC, or super physical contact, evolved from the PC connector and has a better surface finish. UPC connectors rely on machine polishing, and the return loss is higher than PC connectors, close to -50dB or higher. The circular finish it produces during the polishing process allows the optical fiber to contact high points near the core of the optical fiber where the light propagates. In addition, when using UPC connectors, ensure that the specifications of the laser can handle the return loss generated by the UPC connector. It should be noted that repeated connection and disconnection will cause the quality and performance of the UPC connector end face to decrease.
What is APC fiber optic connector?
APC refers to angular physical contact. Unlike UPC connectors, the end face of the APC connector is precisely polished and forms an angle of 8 degrees with the fiber cladding. This makes most of the return loss reflected into the cladding and will not interfere with the transmission signal , Damage the laser source.
