- (1) FC / FC type optical fiber connector, this connector was first developed by the Japanese NIT. Previous FC Ferrule Connector, abbreviations, and that its external reinforcement is the use of metal fastening method for the turnbuckle; show that after an FC connector docking for a flat butt. Such connector structure is simple, easy to operate, easy production, but the fiber end face is more sensitive to dust, and prone to Fresnel reflection, is more difficult to improve the return loss.

- (2) FC / PC fiber optic connector, this connector is an improved version of the FC / FC-type connector. The significance of the FC with the former the same; PC stands for the Physical Connection, indicating that the docking face is the physical contact, that is, side to appear before the convex arch structure. Compared with the former, this connector external structure has not changed, just butt end face of the structure from flat to arched convex. This type of connector insertion loss and return loss performance compared with the former have a more substantial increase.

 - (3) SC (F04) fiber optic connectors, which is developed by Japan's NTT molded plug coupled single-mode fiber connectors. Its shell molding, made of molded glass fiber plastic, was rectangular; plug casing (also called pins) made by precision ceramic, coupling sleeve slotted casing structure for the metal, structural dimensions and FC the same type, face processing using a PC or APC polishing; fastening method is the use of plug pin latch without rotation. Such connectors are inexpensive, easy to operate, plug, involved in the loss volatility, higher compressive strength and high density mounting.

- (4) DIN47256-type optical fiber connector, which is developed by the German connector, DIN is the industry standard in Germany, said its figures behind the standard number. This connection uses the structure of the pin and coupling sleeve the same size and the type of FC, PC polishing end processing. Compared with FC connector, its structure is complex, the internal metal structure to control the pressure of the spring to avoid docking excessive pressure damage face.

- (5) biconical connector (Biconical Connector), this type of fiber optic connectors, the most representative products are developed by Bell Laboratories in the U.S., was by the two ends of precision molding forming a truncated conical The shape of the cylinder plug and an internal plastic sleeve equipped with a double cone coupling components.