The main parameters that affect the transmission performance of optical fiber include the attenuation and chromatic dispersion of optical fiber.
The attenuation coefficient of optical fiber decreases as the wavelength increases. The smaller the attenuation coefficient, the longer the transmission distance without relay.
Chromatic dispersion refers to the phenomenon of light pulse broadening caused by the different group speeds of components with different wavelength in the optical fiber in the light source spectrum, which limits the transmission capacity and transmission distance. The smaller the dispersion, the longer the transmission distance without relay.
Different types of single mode fibers are classified according to their attenuation range, dispersion value, etc.
衰減:Attenuation
OH吸收峰:OH absorption peak
零色散波長(cháng):Zero dispersion wavelength
According to the performance of optical fiber, combined with the characteristics of the transmission distance of PON network optical fiber not greater than 20km, and many turning points in the last kilometer, let's get to know a few commonly used types of single mode fiber.
G.652D optical fiber is currently the most widely used single mode fiber in China. It is mainly used in the feeder section and wiring section of the PON network.
The main characteristic of G.657 optical fiber is good bending resistance. G.657 optical fiber is divided into two subtypes, A and B. The performance and application environment of G.657A optical fiber are similar to those of G.652D optical fiber, and it can be interconnected with G.652D. Its bending radius can reach 7.5mm, which is suitable for realizing FTTH information transmission and installation in narrow places such as indoors or buildings.
The lower limit of the mode field diameter of the G.657B optical fiber is smaller than that of G.657A and G.652D, and the upper limit is the same. It is different from the G.652D standard. And the connection may have large losses. Therefore, it has limited applications.
G.654E optical fiber is a new type of optical fiber. This optical fiber has the characteristics of large effective area and low loss coefficient. It is the first choice for 200G, 400G and Tbit/s ultra-high-speed transmission technology in the future.
光分配點:Light distribution point
饋線段:Feeder section
配線段:Wiring section
CO機房:CO machine room
戶外地下:Outdoor underground
用戶接入點:Access point of user
入戶段:FTTP section
室内:Indoor