2.OPTICAL FIBER
2.1 General
This part illustrates the characteristics of optical fiber as recommended in ITU-T G.657A1.
The optical fiber is made of high pure silica and germanium doped silica. UV curable acrylate material is applied over fiber cladding as optical fiber primary protective coating. The detail data of optical fiber performance are shown in the following table.
G657A1 fiber | Specification |
Attenuation | @1310 nm | ≦ 0.35 dB/km |
@1383 nm | ≦ 0.35 dB/km |
@1460 nm | ≦ 0.25 dB/km |
@1490 nm | - |
@1550 nm | ≦ 0.21 dB/km |
@1625 nm | ≦ 0.23 dB/km |
Attenuation vs. wavelength | @1310 nm | 1285~1330 nm | ≦ 0.03 dB/km |
@1550 nm | 1525~1575 nm | ≦ 0.02 dB/km |
Dispersion coefficient | 1285~1340 nm | -3.0~3.0 ps/(nm?km) |
| @1550 nm | 18 ps/(nm?km) |
| @1625 nm | 22 ps/(nm?km) |
Zero dispersion wavelength | 1300~1324 nm |
Zero dispersion slope | ≦ 0.090 ps/(nm2?km) |
Zero dispersion slope(typical) | ≦ 0.086 ps/(nm2?km) |
Polarization Mode Dispersion | Maximum individual fiber | 0.2 ps/√km |
Design Link(Value M=20,Q Q=0.01%) | 0.1 ps/√km |
Cable cut-off wavelength λcc | ≦ 1260 nm |
Mode Field Diameter | @1310 nm | 9.2±0.4 μm |
@1550 nm | 10.1±0.5 μm |
Group Index of Refraction(typical) | @1310 nm | 1.466 |
@1550 nm | 1.467 |
2.2 Optical Characteristics
2.2 Backscatter Characteristics (@1550 nm)
Step (Mean of bidirectional measurement) | ≦ 0.05 dB |
Irregularities over fiber length and point discontinuity | ≦ 0.05 dB |
Difference backscatter coefficient (Bidirectional measurement) | ≦ 0.03 dB/km |
2.3 Geometrical Characteristics
Cladding diameter | 124.8±1.0 μm |
Cladding non-circularity | ≦ 0.7% |
Coating diameter | 245±7 μm |
Coating/cladding concentricity error | ≦ 12.0 μm |
Coating non-circularity | ≦ 6.0% |
Core/cladding concentricity error | ≦ 0.6 μm |
Curl (Radius) | ≧ 4 m |
2.4 Environmental Characteristics (@1310/@1550 nm)
Attenuation at temperature cycling △ α(-60~+85 ℃) | ≦ 0.05 dB/km |
Attenuation at temperature-humidity cycling(-10~+85 ℃, 98% R.H.) | ≦ 0.05 dB/km |
Attenuation at damp heat dependence(85℃, 85% R.H. 30 days) | ≦ 0.05 dB/km |
Attenuation at watersoak dependence (23℃, 30 days) | ≦ 0.05 dB/km |
2.5 Mechanical Characteristics
Proof test (off line) | ≧ 9.0 N (≧ 100 kpsi) |
Attenuation at bending dependence (@1550 nm) | 1 turn, 15 mm diameter | - |
1 turn, 20 mm diameter | ≦ 0.1 dB |
10 turn, 30mm diameter | ≦ 0.1dB |
100 turns, 50 mm diameter | ≦ 0.05 dB/km |
Coating strip force (typical) | 1.7 N |
Dynamics stress corrosion susceptibility parameter (nd, Typical) | ≧ 20 |