652 fiber is designed to have a zero-dispersion wavelength near 1310 nm, therefore it is optimized for operation in the 1310nm band and can also operate at 1550 nm. B . Hollow-core fiber (HCF) presents several compelling advantages over conventional solid-core fibers like G. D, including ultra-low latency, high capacity, and reduced attenuation. It details the fiber's geometrical, optical. There are 19 different single mode optical fiber specifications defined by the ITU-T, among which G. 652 fiber is the most commonly used. It is a continuation of the previous review published in 2023 and should be construed in conjunction therewith.