SFP optical module MaxLink ML-S31D-20 single-mode 1310 nm 20 km

The MaxLink ML-S31D-20 SFP optical module is a single-mode transceiver designed for fiber-optic links that require reliable point-to-point transmission over longer distances. Operating at a wavelength of 1310 nm, this compact SFP module supports a maximum reach of up to 20 km over single-mode fiber. It is intended for insertion into standard SFP ports on switches, routers and media converters to provide a stable optical uplink for campus networks, access rings and telecom interconnects.

Advantages

The module delivers cost-effective single-mode connectivity in a compact SFP form factor suitable for hot-plug installation. Its 1310 nm wavelength balances dispersion and attenuation for mid-range single-mode links, while the 20 km reach covers typical campus and metropolitan segments without the need for intermediate amplification. Compatibility with common SFP sockets enables straightforward integration into existing network equipment and media converters.

Suitable for

• Switch-to-switch uplinks in campus and enterprise networks
• Router and media converter optical interfaces
• Longer access links and telecom aggregation up to 20 km
• Single-mode fiber backbone segments and point-to-point connections

Key specifications

• Form factor: SFP (small form-factor pluggable)
• Fiber type: single-mode fiber (SMF)
• Wavelength: 1310 nm
• Maximum transmission distance: up to 20 km (depending on link budget and fiber quality)
• Interface: optical LC connector
• Typical use: data uplinks, campus links, telecom interconnects

How to use

Ensure both endpoints use single-mode fiber and LC connectors, and verify fiber continuity and connector cleanliness before insertion. Power down or follow hot-plug procedures recommended by your network equipment vendor, then insert the SFP module into an available SFP slot until it seats firmly. Connect the single-mode fiber patch cable to the module's LC port. After insertion, confirm link status via the switch or router management interface and monitor optical levels if available. To remove, follow the equipment’s hot-unplug guidance or power-down procedures and gently extract the module by the housing.

Usage recommendations

Use clean, properly rated single-mode fiber cables and maintain dust caps on the optical connector when the module is not connected. Verify that the host device supports third-party SFP modules if required, and check link parameters such as receive/transmit power to ensure the 20 km reach is achievable with your fiber plant.