| Definition | The maximum amount of power loss that can be tolerated in a fiber optic system while maintaining acceptable performance |
| Formula | Total Loss Budget = Transmitter Power – Receiver Sensitivity |
| Components of Loss | Fiber Attenuation, Connector Loss, Splice Loss, System Margin |
| Fiber Attenuation (Single-mode) | Typically 0.35 dB/km at 1310 nm, 0.25 dB/km at 1550 nm |
| Fiber Attenuation (Multi-mode) | Typically 3.0 dB/km at 850 nm, 1.0 dB/km at 1300 nm |
| Connector Loss | Typically 0.3 to 0.5 dB per mated pair |
| Splice Loss | Typically 0.1 dB for fusion splices, 0.5 dB for mechanical splices |
| System Margin | Usually 3 to 6 dB, accounts for aging and environmental factors |
| Wavelengths | Common: 850 nm, 1300 nm (multi-mode), 1310 nm, 1550 nm (single-mode) |
| Fiber Types | Single-mode (OS1, OS2), Multi-mode (OM1, OM2, OM3, OM4, OM5) |
| Calculation Formula | Total Loss = (Fiber Length × Attenuation/km) + (Number of Connectors × Connector Loss) + (Number of Splices × Splice Loss) + System Margin |
| Transmitter Power | Typically ranges from -10 dBm to +5 dBm |
| Receiver Sensitivity | Typically ranges from -34 dBm to -20 dBm |
| Power Budget | Transmitter Power – Receiver Sensitivity |
| Optical Return Loss (ORL) | Measure of reflected light, typically > 20 dB for good performance |
| Dispersion | Pulse spreading that can limit bandwidth, more significant in long-distance links |
| Bandwidth-Distance Product | Measure of data-carrying capacity, typically in MHz·km |
| Testing Methods | OTDR (Optical Time Domain Reflectometer), Light Source/Power Meter |
| Standards | TIA/EIA-568, ISO/IEC 11801 |
| Factors Affecting Loss | Bend radius, cable quality, installation practices, environmental conditions |
| Bend Loss | Increased loss due to tight bends in fiber, more critical in single-mode |
| Macrobend Loss | Loss due to large-scale bends in fiber installation |
| Microbend Loss | Loss due to small-scale distortions in fiber geometry |
| Temperature Effects | Can cause expansion/contraction, affecting attenuation |
| Mechanical Stress | Can increase attenuation if fiber is stretched or compressed |
| Aging Effects | Gradual increase in attenuation over time |
| Maintenance Considerations | Regular cleaning of connectors, avoiding physical stress on cables |
| Troubleshooting Tools | Visual Fault Locators (VFL), Optical Loss Test Sets (OLTS) |
| Link Performance Metrics | Bit Error Rate (BER), Eye Diagram |
| Future-proofing | Consider higher loss budgets for potential upgrades or extensions |
| Documentation | Maintain detailed records of link characteristics and measurements |