When planning long-distance trunk lines, it’s crucial to estimate attenuation in advance to avoid excessive loss after installation, which would necessitate re-laying the fiber optic cables.
In fiber optic cabling, it’s common to calculate the maximum loss over a defined length of the line. The calculation formula for fiber optic attenuation is as follows:
The Total Link Loss = Cable Attenuation + Connector Loss + Splice Loss
Cable Attenuation(dB) = Maximum Cable Attenuation Coefficient(dB/km) x Length(km)
Connector Loss(dB) = Number of Connector Pairs x Connector Loss Alowance(dB)
Splice Loss (dB) = Number of Splices x Splice Loss Allowance(dB)
It is important to note that the total link loss calculated in this way is only an estimated value, as other factors neec to be assumed, and actual fiber attenuation might be higher.
G.652 Fiber: Commonly used for short distances with two operating windows: 1310nm and 1550nm.
G.655 Fiber: Generally used for long distances with one operating window: 1550nm(optimized for 1550nm).
Typically, G.655 fiber at 1550 nm has a lower natural attenuation than G.652 fiber at the same wavelength.
In common single-mode fibers, the natural attenuation at 1550nm is approximately 0.2 to 0.25 dB/km, at 1310nm it is about 0.35 to 0.4 dB/km, and at 850 nm it is about 2.5dB/km.
The variability in natural attenuation values is often due to the manufacturing process and the presence of impurities in the fiber.
Splice Loss:
According to TlA/ElA standards, the maximum splice loss is 0.3 dB. However, under normal circumstances, splice loss typically ranges from 0.08 dB to 0.1 dB.
Connector insertion Loss:
High-Quality Connector Insertion Loss: 0.08 to 0.2 dB
Standard Connector Insertion Loss: 0.15 to 0.3 dB
Splitter Loss:
1:2 Splitter IL(Un-connectorized) ≤ 3.8 dB
1:2 Splitter IL(Connectorized) ≤ 4.1 dB
1:8 Splitter IL(Un-connectorized) ≤ 10.3 dB
1:8 Splitter IL(Connectorized) ≤ 10.5 dB
1:16 Splitter IL(Un-connectorized) ≤ 13.6 dB
1:16 Splitter IL(Connectorized) ≤ 13.8 dB
1:32, 1:64 Splitter …
Conclusion
Never underestimate the impact of product quality.
High-quality products mean lower attenuation, which determines the overall quality of the project and reduces the likelihood of rework for engineers.
lf you are interested in specific loss values for other products, feel free to contact us and reach out.