Loss values ​​of various optical splitters

Optical splitter loss depends on the splitter type, number of output ports, and additional excess losses, typically ranging from 0.5 dB to over 20 dB for high split ratios.

Theoretical Split Loss

The ideal insertion loss of a 1×N splitter is determined by the number of output ports using the formula: Loss (dB) = 10 × log₁₀(N)

• 1×2 splitter: 3.0 dB
• 1×4 splitter: 6.0 dB
• 1×8 splitter: 9.0 dB
• 1×16 splitter: 12.0 dB
• 1×32 splitter: 15.0 dB
• 1×64 splitter: 18.0 dB This represents the ideal power division without considering imperfections .

Excess Loss

Real-world splitters have excess loss due to internal imperfections, core misalignment, and packaging. Typical values are:

• PLC splitters: 0.5–2.0 dB depending on the split ratio and quality
• FBT splitters: Slightly higher at large split ratios, often 1–3 dB for 1×16 or higher The total insertion loss is the sum of the theoretical split loss and the excess loss from the datasheet.

Practical Example

For a 1×8 PLC splitter at 1550 nm with 0.8 dB excess loss, two connectors at 0.3 dB each, four fusion splices at 0.1 dB each, and a 2 dB engineering margin:

• Theoretical split loss: 10 × log₁₀(8) = 9.03 dB
• Total branch loss: 9.03 + 0.8 + (2×0.3) + (4×0.1) + 2 = 12.83 dB This shows how splitter loss combines with other network elements to affect the optical power budget .

Summary of Typical Loss Ranges

Key Considerations

• Cascading splitters increases total loss due to the additive effect of each stage.
• Connector and splice losses must be included in the network budget.
• Engineering margin accounts for aging, dirt, temperature, and measurement tolerances.
• Always refer to the manufacturer datasheet for precise excess loss values when designing a network . By understanding these loss values, network designers can ensure sufficient optical power reaches each endpoint, maintaining reliable operation in PON and FTTH deployments.