Classification and main specification parameters of fiber optic connectors

Fiber optic connectors are connectors installed at both ends of a section of optical fiber, mainly used for optical wiring. According to the type of optical fiber: single-mode fiber connector (generally G.652 fiber: fiber inner diameter 9um, outer diameter 125um), multi-mode fiber connector According to the connection forms of fiber optic connectors, they can be divided into FC, SC, ST, LC, MU, MTRJ, etc. Currently, the commonly used ones are FC, SC, ST, LC, etc, 1. FC type - originally developed by NTT Japan. The external reinforcement is made of metal sleeves and fastened with screw buckles. This type of connector is commonly used for testing equipment. 2. SC type - a molded plug-in coupling connector developed by NTT Corporation in Japan. The outer shell is made of molded fiberglass plastic and has a rectangular shape; The pins are made of precision ceramics, and the coupling sleeve is a metal slotted sleeve structure. The fastening method adopts a plug-in pin type, which does not require rotation. 3. LC type - designed by Lucent Technologies. The outer diameter of the casing is 1.25mm, which is half of the commonly used FC-SC and ST casing outer diameter of 2.5mm. Improve the application density of connectors. According to the end face of the inner pins of the fiber optic connector connector: PC, SPC, UPC, APC According to the diameter of the fiber optic connector, it can be divided into: Φ 3, Φ 2, and Φ 0.9 The performance of fiber optic connectors mainly includes optical performance, interchangeability performance, mechanical performance, environmental performance, and lifespan. The most important indicators are insertion loss and return loss. 1. Optical module transmission rate: 100Mbps, 1G, 10GE, etc 2. Optical module emission power and reception sensitivity: Emission power refers to the light intensity at the emission end, while reception sensitivity refers to the detectable light intensity. Both are measured in dBm and are important parameters that affect transmission distance. The transmission distance of optical modules is mainly limited by two aspects: loss and dispersion. The loss limit can be estimated based on the formula: loss limited distance=(emitted optical power - received sensitivity)/fiber attenuation. The attenuation of optical fibers is related to the actual selected optical fibers. Generally, the current G.652 fiber can achieve 0.5dB/km in the 1310nm band, 0.3dB/km or even better in the 1550nm band. 50um multimode fiber operates at 4dB/km in the 850nm band and 2dB/km in the 1310nm band. For 100Mbps and 1G optical modules, dispersion limitation is much greater than loss limitation and can be ignored. 3. The 10GE optical module follows the 802.3ae standard, and the transmission distance is related to the type of fiber used and the optical performance of the optical module. 4. The saturated optical power value refers to the maximum detectable optical power at the receiving end of the optical module, usually -3ddB. When the received optical power is greater than the saturated optical power, it can also cause errors. Therefore, for optical modules with high emission power, testing without attenuation loop will result in errors.