What is ITU-T G.654 Fiber


ITU-T Recommend G.654 fiber is a cut-off shifted single-mode optical fiber especially used for high bandwidth long distance transmission. The G. 654 fiber is a single mode optical fiber and cable which has the zero-dispersion
opticalfiberwavelengths around 1300nm, the fiber with loss minimized and cut-off wavelength shifted at around 1550nm. the fiber standard was firstly introduced in year 1988. The ITU-T G.654 Fiber could be applied in higher bandwidht submarine systems, back haul system.


  • 100 Gb/s, 400 Gb/s, and 1 Tb/s using coherent modulation formats
  • Dense wave-division multiplexing
  • Long unrepeatered spans such as those encountered in remote regions
  • Optically-routed mesh networks
  • Terabit super-channels
  • Ultra-long haul 10 Gb/s and 100 Gb/s


ParametersITU-T G.654 AITU-T G.654 BITU-T G.654 CITU-T G.654 D
Fiber Attribute
Mode Field DiameterWavelenths1550nm1550nm1550nm1550nm
Core diameter9.5 ~ 10.5um9.5 ~ 13.0um9.5 ~ 10.5um11.5 ~ 15.0um
Tolerance± 0.7um± 0.7um± 0.7um± 0.7um
Cladding DiameterClad Diameter125um125um125um125um
Tolerance± 0.7um± 1um± 0.7um± 0.7um
Clad Non-Circularitymaximum≤2.0 %≤2.0 %≤2.0 %≤2.0 %
Core/Clad Concentricity Error (Offset)maximum≤ 0.8um≤ 0.8um≤ 0.8um≤ 0.8um
Cable Cutoff Wavelength (λcc)maximum≤ 1530 nm≤ 1530 nm≤ 1530 nm≤ 1530 nm
Macrobend AttenuationRadius30mm30mm30mm30mm
number of turns100 turns100 turns100 turns100 turns
maximum at 1652nm0.5dB0.5dB0.5dB0.5dB
Proof StressMinimum0.69Gpa0.69Gpa0.69Gpa0.69Gpa
Chromatic Dispersion CoefficientD1550max20px/nm.km20px/nm.km20px/nm.km23px/nm.km
Uncabled Fiber PMD CoefficientMaximumNote(2)Note(2)Note(2)Note(2)
Cable Attribute
Attenuation coefficient (Note 1)Maximum at 1550 nm0.22 dB/km0.22 dB/km0.22 dB/km0.22 dB/km
PMD coefficient
(Note 2)
M20 cables20 cables20 cables20 cables
Maximum PMDQ 0.5 ps/√km 0.5 ps/√km 0.5 ps/√km 0.5 ps/√km
NOTE 1 – The attenuation coefficient values listed in this table should not be applied to short cables such as jumper cables. For example, [b-IEC 60794-2-11] specifies the attenuation coefficient of indoor cable as 1.0 dB/km or less.
NOTE 2 – According to clause 6.2, a maximum PMDQ value on uncabled fibre is specified in order to support the primary requirement on cable PMDQ.

Source from: Tarluz Blog: What is G 654 Fiber