ITU-T G.65x fibers are specified to perform for different applications. G.653 fiber is specified at 1310 nm and 1550 nm but with a zero chromatic dispersion slope in the 1550nm region. G.654 fiber is loss-minimized and cut-off shifted at a wavelength around 1500 nm. G.656 fiber is specified at 1460 nm and 1625 nm but with a non-zero chromatic dispersion slope in these wavelength regions. Here’s a comparison among them:
|Specified Wavelength (nm)
|Zero-Dispersion/Non-dispersion-shifted fiber, or standard SMF.
|1310, 1550, 1625 (C and D excluded)
|LAN, MAN, access networks and CWDM transmission.
|Dispersion-shifted optical fiber
|1310 to 1550
|Long-haul single-mode transmission systems using erbium-doped fiber amplifiers (EDFA).
|Cut-off shifted optical fiber
|Higher bandwidth submarine systems and back haul systems.
|Non-zero dispersion-shifted optical fiber (NZDSF)
|1550 to 1625
|Long-haul systems that use Dense WDM (DWDM) transmission.
|Non-Zero dispersion for Wideband Optical Transport fiber
|1460 to 1625
|Long-haul systems that use CWDM and DWDM transmission over the specified wavelength range
|Bending loss insensitive optical fiber for access networks
|1260 to 1625
|Fiber-to-the-home (FTTH) networks.
Different single mode optical fibers defined by ITU-T include G.652, G.653, G.654, G.655, G.656 and G.657. Each single mode fiber type has its own area of application and the evolution of these optical fiber specifications reflects the evolution of transmission system technology from the earliest installation of single mode optical fiber through to the present day. Choosing the right one for your project can be vital in terms of performance, cost, reliability and safety.