In optical fiber communication systems, in order to meet the needs of flexible connectors between different devices and systems, it is necessary to have a device that can be flexibly connected between optical fiber and optical fiber, between optical fiber and devices (including active devices, passive devices, and optical fiber sensors), between optical fiber and instruments, and between optical fiber and systems. The device is capable of transmitting optical signals according to the required channel. The device that can achieve this function is called a fiber optic adapter (fiber optic flange), which is an essential and widely used optical passive component in fiber optic communication systems.
With the further development of fiber optic communication, different countries and manufacturers have successively developed different fiber optic adapters. According to incomplete statistics, there are about 30 types of fiber optic adapters used internationally so far. Usually, fiber optic adapters can be divided into single mode fiber optic adapters and multimode fiber optic adapters based on different transmission media; According to the structural type of the connector, it can be divided into FC.SC.ST.LC.MTRJ.MU.MT.MPO, etc; According to the shape of the fiber end face, it can be divided into PC, UPC, and APC types; According to the number of fiber cores, there are single core and dual core types. There are also many models and varieties of fiber optic adapters that match it, each with its own technical characteristics. But their function is the same, which is to connect the fiber optic (optical cable) plugs together, and the fiber optic is connected.
The main requirements for fiber optic adapters are low insertion loss, high reflection loss, good repeatability, stable environment, and good mechanical performance. The cladding of a single-mode fiber is 125um (equivalent to the thickness of a hair), and the diameter of its fiber core (the light passing part of the fiber) is only 9um. The task of the fiber connector is to accurately connect the 9um fiber cores together, allowing 98% of the light to pass through, and the technical requirements are very precise.
