What are the common fiber optic connectors?

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 plastics as transmission media; according to the structure of the connector, it can be divided into: FC , SC, ST, LC, DIN, MU, MT, etc. in various forms.

(1) FC fiber optic connector
The butt end of the ceramic pin used in the FC type connector. This type of connector is simple in structure, easy to operate, and easy to manufacture, but the fiber end is more sensitive to dust and prone to Fresnel reflection, making it difficult to improve return loss performance.
This type of connector has been improved by adopting a contact pin (PC) with a spherical butt end surface, while the external structure has not changed, so that the insertion loss and return loss performance have been greatly improved.

(2) SC type fiber optic connector
The outer shell of this fiber optic connector is rectangular, and the structure size of the ferrule and coupling sleeve used is exactly the same as that of the FC type. Among them, the end faces of the pins are mostly PC or APC-type grinding; the fastening method is the plug-in pin-bolt type, which does not need to be rotated. This type of connector is cheap, easy to plug and unplug, has small fluctuations in insertion loss, high compressive strength, and high installation density.

(3) ST type fiber optic connector
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.

(4) LC type connector
The size of the pin and sleeve used in this connector is half the size of ordinary SC, FC, etc., which is 1.25mm. This can increase the density of optical fiber connectors in the optical fiber distribution frame. At present, in terms of single-mode SFF, LC-type connectors have actually occupied a dominant position, and their applications in multi-mode are also growing rapidly.

(5) DIN47256 fiber optic connector
 This is a connector developed in Germany. The structure dimensions of the pin and coupling sleeve used in this connector are the same as those of the FC type, and the end face treatment adopts PC grinding method. 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.

(6) MT-RJ type connector
MT-RJ aligns the optical fiber through the guide pins installed on both sides of the small sleeve. In order to facilitate the connection with the optical transceiver, the optical fiber on the end face of the connector is designed as a double-core (interval 0.75mm) arrangement, which is mainly used for data transmission. A generation of high-density fiber optic connectors.

(7) MU type connector
The MU connector is the world's smallest single-core optical fiber connector developed by NTT based on the currently 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 installation. Using MU's 1.25mm diameter ferrule, NTT has developed the MU connector series.