These fibers are intended to be compatible with the G. 657 are ITU-T standardized singlemode fiber types used across long-haul, metro, ODN, and FTTH networks. Each fiber type is engineered with different refractive index profiles, dispersion properties, and bending performance to support specific applications—from long-distance. ITU-T G. 655 are the two options commonly used. D, feature a reduced water peak that allows them to be used in the wavelength region between 1310. G652: Standard single mode fiber, zero dispersion point is in 1300nm,divides into G652A,B,C,D. G652A and B have a zero dispersion wavelength point at 1310 nm, which makes it a natural fit for operation in the 1310 nm band. com/pdf/Knowledgecenter/Mixing%20of%20G655%20and%20G652%20Optical%20Fibers.