652 is the standard single-mode fiber used in access and metro networks, optimized for 1310 nm transmission with normal dispersion at 1550 nm, while G. Each fiber type is engineered with different refractive index profiles, dispersion properties, and bending performance to support specific applications—from long-distance. Two commonly used single mode fiber specifications are G. This guide provides a detailed comparison between G. It has G652A, B, C and D four versions. 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. However, they are not. ITU-T G. 655 are the two options commonly used. 654 (cutoff wavelength-shifted fiber), G.