Optical fiber connectors can be divided into common silicon-based optical fiber single-mode and multi-mode connectors according to different transmission media, and other optical fiber connectors such as plastic as the transmission medium; according to the structure of the connector, it can be divided into: FC , SC, ST, LC, D4, DIN, MU, MT and other forms.Among them, ST connectors are usually used for wiring equipment, such as fiber distribution frames, fiber modules, etc.; while SC and MT connectors are usually used for network equipment.According to the shape of the fiber end face, it is divided into FC, PC (including SPC or UPC) and APC; according to the number of fiber cores, there are single-core and multi-core (such as MT-RJ) points.Optical fiber connectors are widely used and have a wide variety.In the actual application process, we generally distinguish according to the structure of the optical fiber connector.Here are some common fiber optic connectors:This connector was first developed by Japanese NTT.FC is the abbreviation of Ferrule Connector, indicating that its 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 the plane contact method (FC).This type of connector is simple in structure, convenient in operation and easy to manufacture, but the fiber end is more sensitive to dust, and is prone to Fresnel reflection, making it difficult to improve return loss performance.Later, this type of connector was improved, and the contact pin (PC) with spherical end face was adopted, and the external structure was not changed, which greatly improved the insertion loss and return loss performance.This is a fiber optic connector developed by Japan's NTT company.Its shell is rectangular, and the structure and dimensions of the pins and coupling sleeves used are exactly the same as those of the FC type.Among them, the end face of the pin mostly adopts PC or APC grinding method; the fastening method adopts the plug-in latch type, which does not need to be rotated.This type of connector is inexpensive, easy to plug and unplug, small fluctuation 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 core of the ST connector is exposed, and the core of the SC connector is inside the connector.The most representative product of this type of fiber optic connector was developed by Bell Labs in the United States. It consists of two precision-molded cylindrical plugs with frusto-conical ends and a double-conical plastic sleeve inside. The coupling components of the cylinder are composed.DIN47256 fiber optic connector This is a connector developed in Germany.The pins and coupling sleeves used in this connector have the same structural dimensions as the FC type, and the end face treatment adopts PC grinding.Compared with the FC type connector, its structure is more complicated, and there is a spring that controls 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 started from the MT connector developed by NTT. It has the same latching mechanism as the RJ-45 type LAN electrical connector. It is aligned with the optical fiber through the guide pins installed on both sides of the small sleeve. The optical fiber on the end face of the connector is designed in a double-core (0.75mm interval) arrangement. It is the next-generation high-density optical fiber connector mainly used for data transmission.The LC type connector is researched and developed by the famous Bell Research Institute and is made of a modular jack (RJ) latch mechanism that is easy to operate.The size of the pins and sleeves 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 optic distribution frame.Currently, in single-mode SFF, LC-type connectors have actually dominated, and the application in multi-mode is also growing rapidly.MU (Miniature unit Coupling) connector is the world's smallest single-core optical fiber connector developed by NTT based on the most used SC-type connector.The connector uses a 1.25mm diameter sleeve and a self-retaining mechanism, which has the advantage of enabling high-density mounting.Utilizing MU's 1.25mm diameter sleeve, NTT has developed the MU connector series.They are available with receptacle-type connectors (MU-A series) for fiber optic connections; backplane connectors with self-retaining mechanisms (MU-B series) and simplified sockets for connecting LD/PD modules to plugs (MU-SR series) Wait.With the rapid development of optical fiber networks in the direction of larger bandwidth and larger capacity and the wide application of DWDM technology, the demand for MU-type connectors will also increase rapidly.In 2012, a domestic communication company independently developed a MC connector with a smaller volume and higher density than the LC connector.Sunsea MC fiber optic connector is a high-density single-core fiber optic connector, suitable for various high-density occasions, such as large-capacity central computer rooms and high-density data centers.The MC optical fiber active connector has a high density, which can reach up to twice that of the LC connector in the same space, making it the smallest and highest density connector in the world.Fiber optic connectors can also refer to FICON, the IBM mainframe channel that FIber Connector introduced in 1998 with the G5 server.It is based on the Fibre Channel standard and increases ESCON's half-duplex transfer rate of 17MB/s to full-duplex 100MB/s.Each FICON channel can support up to 4000 I/O operations per second, which is equivalent to 8 ESCON channels.