Transmission distance of single-mode gigabit optical module

Gigabit single-mode optical modules typically support transmission distances ranging from 10 km up to 120 km, depending on the module type and wavelength.Typical Transmission Distances

Gigabit single-mode SFP modules are designed for long-distance fiber optic communication. Common transmission distances include:

• 10 km: Standard 1000BASE-LX/LH modules operating at 1310 nm on single-mode fiber .
• 15 km to 40 km: Extended reach modules for enterprise or metro networks .
• 80 km: Long-reach SFP modules, often using 1310 nm wavelength with high transmit power and sensitive receivers .
• 120 km or more: Ultra-long-reach modules, typically using 1550 nm wavelength for minimal signal attenuation over very long distances .

Factors Affecting Transmission Distance

1. Wavelength: Modules operating at 1310 nm are common for standard distances (up to 10–80 km), while 1550 nm modules are preferred for ultra-long distances due to lower fiber attenuation .
2. Transmit Power and Receiver Sensitivity: Higher optical output power and more sensitive receivers extend the achievable distance.
3. Fiber Quality and Type: Standard single-mode fiber (SMF, G.652) is used for long-distance links. Fiber loss, splices, and connectors can reduce effective distance.
4. Environmental Conditions: Temperature, bending, and installation quality can impact signal integrity and maximum reach.

Practical Considerations

• SFP Compatibility: Ensure the module is compatible with the switch or router port and supports the required standard (e.g., 1000BASE-LX/LH, 1000BASE-BX10).
• Single-Strand vs Dual-Strand: Some modules, like 1000BASE-BX10-D/U, operate over a single fiber strand using different wavelengths for transmit and receive .
• Digital Optical Monitoring (DOM): Many modules support DOM to monitor real-time optical power, temperature, and other parameters, which helps maintain reliable long-distance links . In summary, Gigabit single-mode optical modules provide flexible long-distance connectivity, with distances ranging from 10 km for standard modules up to 120 km or more for high-power, long-reach modules, depending on wavelength, fiber quality, and module specifications .