Optical fiber connectors can be divided into: FC, SC, ST, LC, D4, DIN, MU, MT and other forms according to the structure of the connector.
FC type fiber optic connector
This connector was first developed by NTT in Japan. FC is the abbreviation of Ferrule Connector, which means that the external reinforcement method is a metal sleeve, and the fastening method is a turnbuckle. The earliest, FC-type connector, the mating end face of the ceramic pin used is a flat contact method (FC). This type of connector is simple in structure, easy to operate, and easy to manufacture, but the end of the fiber is sensitive to dust, prone to Fresnel reflection, and difficult to improve return loss performance. Later, this connector was improved, and the contact pin (PC) with a spherical end face was used, which greatly improved the performance of insertion loss and return loss without changing the external structure.
SC type fiber optic connector
This is a fiber optic connector developed by NTT Corporation of Japan. Its shell is rectangular, and the structure and size of the pins and coupling sleeves used are exactly the same as those of the FC type. Among them, the PC or APC grinding method is mostly used for the end face of the pin; the fastening method is a bolt type without rotation. This kind of connector is low in price, easy to plug and unplug, has small fluctuations in insertion loss, high compressive strength, and high installation density.
ST and SC interfaces are two types of fiber optic connectors. For 10Base-F connection, the connector is usually ST type, and for 100Base-FX, the connector is mostly SC type. The wire core of the ST connector is exposed, and the wire core of the SC connector is inside the connector.
Double cone connector
The most representative product of this type of fiber optic connector is developed by Bell Laboratories in the United States. It consists of two precision-molded cylindrical plugs with frusto-conical ends and an inner bi-conical plastic sleeve. The coupling parts of the cylinder are composed. DIN47256 Fiber Optic Connector This is a connector developed in Germany. The pins and connecting sleeves used in this connector are the same size as the FC type, and the end surface treatment adopts PC grinding. Compared with the FC type connector, its structure is more complicated, and there is a spring to control the pressure in the internal metal structure, which can avoid damage to the end face due to excessive insertion pressure. In addition, the mechanical precision of this connector is high, so the insertion loss value is small.
MT-RJ type connector
MT-RJ originated from the MT connector developed by NTT. It has the same latching mechanism as an RJ-45 style LAN electrical connector. It is aligned with the fiber by guide pins mounted on both sides of the small ferrule. The optical fiber on the end face of the connector adopts a double-core (0.75mm pitch) arrangement design. It is a next-generation high-density fiber optic connector mainly used for data transmission.
LC type connector
Developed by the renowned Bell Research Institute, the LC-type connector is made with an easy-to-operate modular jack (RJ) latch mechanism. The size of the pin and sleeve used is half the size of ordinary SC, FC, etc., which is 1.25mm. This can increase the density of fiber optic connectors in the fiber distribution frame. At present, in single-mode SFF, LC-type connectors actually occupy a dominant position, and their applications in multi-mode are also growing rapidly.
