1.25G BiDi SFP Module, Gigabit SC SMF 40km DDM Transceiver Pair

Product Overview

The Luleey 1.25G BiDi SFP Module is designed for Gigabit Ethernet transmission over single mode single fiber. It uses BiDi wavelength division technology to transmit and receive optical signals through one SC simplex fiber connection, helping network engineers reduce fiber core usage while maintaining stable 1.25Gbps optical performance.

This 40km version is designed for longer single-fiber links than standard 10km or 20km BiDi modules. It is suitable for extended building-to-building links, large campus networks, telecom access, ODF systems, security transmission, long-distance media converter deployment, and remote network access points.

Unlike standard dual-fiber SFP modules that require two fiber cores, this Gigabit SFP SC Module uses a 1310nm/1550nm wavelength pair over one single mode fiber. It is supplied as a matched pair, making it suitable for point-to-point Gigabit fiber links where fiber resources are limited.

Compared with the 20km version, the 40km version provides higher optical budget for longer routes or fiber links with more connector, adapter, patch panel, or ODF loss. It is a better choice when the network needs more transmission margin.

Luleey provides compatibility options for major switch, router, firewall, and media converter platforms, helping users deploy stable long-distance 1G single-fiber links across different network environments.

Features

• 1.25G BiDi SFP Module for long-distance Gigabit single-fiber transmission
• Supplied as a matched transceiver pair
• SC simplex interface for single fiber deployment
• 1310nm / 1550nm wavelength pair
• Supports up to 40km transmission over single mode fiber
• DDM digital diagnostic monitoring support
• 1.25Gbps optical transmission speed
• 3.3V SFP operating voltage
• Designed for long-distance building-to-building and campus fiber links
• SC connector design for ODF, telecom room, access network, and weak-current cabinet deployment
• Compatible with Gigabit switches, routers, firewalls, media converters, servers, and fiber network cards
• Compatible coding options for Cisco, Huawei, MikroTik, Ubiquiti, ZTE, HPE-Aruba, Juniper, Intel, TP-Link, H3C, and more
• Helps save fiber cores compared with dual-fiber SFP modules
• Factory tested by Luleey for stable optical performance

Applications

• Long-Distance Gigabit Ethernet Links
• Single Fiber Network Deployment
• Building-to-Building Fiber Connections
• Campus Fiber Backbone Links
• Telecom Room Fiber Access
• ODF Fiber Distribution Systems
• Fiber Media Converter Deployment
• Security and IP Camera Networks
• Remote Network Access Points
• Router-to-Switch Fiber Connection
• Switch-to-Switch Gigabit Uplink
• Network Firewall Fiber Connection
• Weak-Current Cabinet Installation
• Long-Distance Ethernet Extension

Specifications

Why Choose a 40km 1.25G BiDi SFP Module?

A 40km 1.25G BiDi SFP Module is useful when a network needs Gigabit fiber transmission over one single mode fiber core across longer distances. It provides more optical budget than 10km or 20km versions, making it more suitable for larger campus networks, long building-to-building routes, telecom access links, and links with higher passive loss.

This helps users:

• Save fiber core resources
• Extend Gigabit Ethernet over longer distances
• Reduce cabling cost by using one fiber core
• Support long-distance point-to-point single-fiber links
• Provide more link margin than 20km modules
• Deploy stable fiber connections across campuses, buildings, and access networks

For long-distance Ethernet links, the Luleey 40km Single Fiber SFP Module provides a practical balance between reach, cost, compatibility, and fiber resource efficiency.

20km vs 40km BiDi SFP Module

Both 20km and 40km versions support 1.25G single-fiber transmission, but they are designed for different optical budgets.

Choose the 20km version when the fiber route is shorter and the link loss is low.

Choose the 40km SFP Module when the distance is longer or when the link includes more connectors, patch panels, adapters, ODF points, or passive loss.

How BiDi SFP Transmission Works

BiDi means bidirectional transmission. A BiDi SFP module transmits and receives optical signals over one fiber core by using two different wavelengths.

A typical 1.25G BiDi pair works like this:

| Side | Transmit Wavelength | Receive Wavelength |
|—|—|
| Side A | 1310nm | 1550nm |
| Side B | 1550nm | 1310nm |

Because of this wavelength pairing, BiDi SFP modules must be used in matched pairs. Two modules with the same wavelength direction will not create a normal link.

SC BiDi SFP vs LC BiDi SFP

Both SC and LC BiDi SFP modules can support single-fiber Gigabit transmission, but they are used in different cabling environments.

Choose the SC version when your existing fiber cabling, patch panel, or optical distribution frame uses SC connectors.

Choose the LC version when your equipment or patching system is based on LC interfaces.

1.25G BiDi SFP vs Standard Dual-Fiber SFP

| Module Type | Fiber Usage | Best For |
|—|—|
| Standard Dual-Fiber SFP | Uses two fiber cores | Normal Gigabit fiber links with enough fiber resources |
| 1.25G BiDi SFP Module | Uses one fiber core | Single fiber links and fiber-saving deployments |

Choose a BiDi SFP module when only one fiber core is available or when you want to reduce fiber usage.

Choose a standard dual-fiber SFP module when your fiber infrastructure already provides two available fiber cores.

Compatibility Notes

Luleey can provide compatible coding for different switch, router, firewall, and media converter platforms. Before ordering, please confirm the device brand and model to ensure correct recognition and stable operation.

Common compatibility options include Cisco, Huawei, MikroTik, Ubiquiti, ZTE, HPE-Aruba, Juniper, Intel, H3C, TP-Link, Arista, Brocade, Extreme, Mellanox, and General coding.

Important Pairing Notes

This 1.25G SFP Transceiver should be used with the correct opposite wavelength module. A 1310nm TX / 1550nm RX module should be paired with a 1550nm TX / 1310nm RX module.

Before deployment, confirm:

• The fiber type is single mode
• The connector type is SC
• The link distance is within 40km
• The two modules are matched A/B wavelength pairs
• The host device supports 1G SFP modules
• The compatibility coding matches the switch or router brand
• The optical budget is suitable for the actual fiber link loss
• DDM monitoring is required or supported by the host device

FAQ

What is a 1.25G BiDi SFP Module?

A 1.25G BiDi SFP Module is a Gigabit optical transceiver that transmits and receives data over one single mode fiber core using two different wavelengths.

What is this Gigabit SFP SC Module used for?

It is used for Gigabit Ethernet fiber links, switches, routers, media converters, network firewalls, ODF systems, telecom rooms, campus networks, security networks, and long-distance building-to-building fiber connections.

Does this module use one fiber or two fibers?

It uses one single mode fiber core through an SC simplex connector.

Does this product come as a pair?

Yes. This product should be supplied as a matched BiDi transceiver pair.

What wavelengths does this module use?

It uses a 1310nm / 1550nm wavelength pair. The opposite side must use the reversed wavelength direction.

What is the transmission distance?

This version supports up to 40km transmission over suitable single mode fiber.

What is the difference between the 20km and 40km versions?

The 20km version is suitable for medium-distance fiber links. The 40km version provides more optical budget for longer routes or links with higher passive loss.

Does it support DDM?

Yes. DDM allows monitoring of optical power, temperature, voltage, and laser status when supported by the host device.

What is the difference between SC and LC BiDi SFP modules?

SC BiDi SFP modules are often used with ODF systems, media converters, telecom rooms, and access networks. LC BiDi SFP modules are more common in high-density switches and compact optical equipment.

Is it compatible with Cisco, Huawei, MikroTik or Ubiquiti?

Luleey can provide compatible coding for Cisco, Huawei, MikroTik, Ubiquiti, ZTE, HPE-Aruba, Juniper, Intel, TP-Link, H3C, and other platforms.

Can I use it with multimode fiber?

No. This module is designed for single mode fiber.

Can I use two same-side BiDi modules together?

No. BiDi modules need matched A/B wavelength pairs. Two modules with the same TX/RX direction will not work correctly.

Why choose Luleey 40km 1.25G BiDi SFP modules?

Luleey 40km 1.25G BiDi SFP modules provide long-distance single-fiber Gigabit transmission, DDM monitoring, compatible coding options, and factory-tested optical performance for stable enterprise, campus, security, telecom, ODF, and media converter deployment.