What are the three common types of fiber optic connectors?

LC Connector: The LC connector was developed by the renowned Bell Research Institute, utilizing a modular jack (RJ) latch mechanism for easy operation. The dimensions of its ferrule and sleeve are half the size of those used in standard SC and FC connectors, measuring 1.25mm. This allows for increased connector density in optical distribution frames. Currently, LC-type connectors have established a dominant position in single-mode SFF applications, and their use in multimode applications is also growing rapidly.

FC Fiber Optic Connector: This connector was originally developed by NTT in Japan. FC stands for Ferrule Connector, indicating that its external reinforcement uses a metal sleeve with a screw-type fastening mechanism. Initially, FC-type connectors employed ceramic ferrules with flat end-face contact (FC). This type of connector features a simple structure, easy operation, and straightforward manufacturing, but the fiber end-face is sensitive to dust and prone to Fresnel reflection, making it difficult to improve return loss performance. Later, this connector type was improved by adopting a spherical end-face ferrule (PC) while keeping the external structure unchanged, significantly enhancing insertion loss and return loss performance.

SC Fiber Optic Connector: This is a media converter (optical-electrical converter) developed by NTT Corporation in Japan. Its housing is rectangular in shape, and the structural dimensions of its ferrule and coupling sleeve are identical to those of the FC type, with the ferrule end-face typically polished using PC or APC methods. The fastening mechanism uses a push-pull latch type, requiring no rotation. This type of connector offers low cost, convenient plug-in operation, minimal insertion loss fluctuation, high compressive strength, and high installation density.