Are there any optical modules with a range of 20km

For a 20km transmission distance, single-mode SFP, SFP+, or QSFP28 optical modules are commonly used, typically operating at 1310nm wavelength.

1G SFP Modules

For Gigabit Ethernet (1.25Gbps), SFP optical modules designed for 20km use single-mode fiber and a 1310nm wavelength. These modules are hot-pluggable, use LC connectors, and comply with SFF-8472 standards. They convert electrical signals to optical signals for transmission and back at the receiving end. Typical applications include enterprise campus networks, metropolitan access networks, and infrastructure monitoring systems. They require pairing with compatible SFP ports on switches or fiber converters for proper operation .

10G SFP+ Modules

For 10Gbps links, SFP+ LR (Long Range) modules are suitable for 20km over single-mode fiber. These modules also operate at 1310nm and are designed for long-distance transmission in metro networks or large campus environments. They offer low power consumption, compact size, and high density, making them ideal for upgrading existing network infrastructure without replacing hardware .

100G QSFP28 Modules

For higher-speed applications, QSFP28 100G modules such as the 100GBASE-BX20-D can transmit up to 20km over single-mode fiber using bidirectional wavelengths (e.g., 1310nm TX / 1280nm RX). These modules are suitable for data centers, storage area networks, and high-capacity Ethernet links. They support digital diagnostics monitoring (DDM) and are hot-swappable for flexible deployment .

Key Considerations

When selecting a 20km optical module, consider the following:

• Fiber type: Single-mode fiber is required for 20km distances.
• Wavelength: 1310nm is standard for 20km links; some high-speed modules may use bidirectional wavelengths.
• Data rate: Choose 1G, 10G, or 100G depending on network requirements.
• Connector type: LC connectors are common for SFP/SFP+; QSFP28 may use LC or MPO.
• Compatibility: Ensure the module is compatible with your switch or router brand.
• Power budget and link stability: Check transmitter power and receiver sensitivity to maintain reliable communication. By matching these specifications to your network needs, you can ensure stable and efficient 20km optical links.