Bestselling single-fiber bidirectional (BiDi) fiber solutions include 1G, 10G, 25G, 40G, 100G, and 400G BiDi SFP/SFP+/QSFP modules, which maximize fiber efficiency using wavelength division multiplexing (WDM) over a single strand.

Overview of BiDi Technology

BiDi optical modules enable full-duplex communication over a single fiber by using two different wavelengths for transmit (Tx) and receive (Rx) signals, typically 1310 nm and 1550 nm for single-mode fiber or 850 nm for multimode fiber . This approach reduces fiber usage by up to 50%, simplifies cabling, and lowers installation and maintenance costs . BiDi modules must operate in complementary pairs, where the Tx wavelength of one module matches the Rx wavelength of the other .

Popular BiDi Models and Specifications

• 1G BiDi SFP: Designed for 1G deployment, commonly using 1310/1550 nm or 1310/1490 nm wavelength pairs for distances up to 40 km, and 1550/1490 nm for distances beyond 40 km .
• 10G BiDi SFP+: Supports 10G serial optical communication with 1490/1550 nm wavelength pairs, reaching distances up to 80 km .
• 25G BiDi SFP: Provides 25GBase-BX throughput up to 40 km over single-mode fiber using 1310 nm-TX/1270 nm-RX via LC simplex connectors .
• 40G BiDi QSFP+: Typically uses 850 nm for multimode fiber, with OM3 patch cables supporting 300 m, OM4 up to 400 m, and OM5 up to 500 m .
• 100G BiDi: Duplex LC interface, distances of 75 m (OM3), 100 m (OM4), and 150 m (OM5), suitable for Ethernet and data center applications .
• 400G BiDi: Quad version of 100G BiDi, often using four fiber pairs (4+4 MPO), compatible with digital coherent CFP2 transceivers for high-capacity networks .

Advanced Coherent BiDi Solutions

For mobile transport and high-capacity networks, coherent single-fiber BiDi transceivers operate at a single center frequency (e.g., 193.0 THz) for both upstream and downstream, optimizing power efficiency and minimizing reflections without additional electro-optical nodes . These solutions are ideal for unified end-to-end transport infrastructures in metro and mobile networks.

Deployment Benefits

• Fiber Savings: Reduces fiber usage by up to 50%, critical in fiber-limited environments .
• Cost Efficiency: Lowers installation, leasing, and maintenance costs by maximizing existing fiber infrastructure .
• Simplified Management: Fewer physical connections reduce potential failure points and accelerate network deployment .
• Versatility: Passive BiDi adapters, such as RAD's BiDi QSFP, are compatible with multiple data rates (10G–400G) and existing SFPs, enabling immediate infrastructure upgrades without replacing installed modules .

Key Considerations

When selecting BiDi modules, consider:

• Wavelength pairing and compatibility with existing modules
• Transmission distance and fiber type (single-mode vs multimode)
• Data rate support (1G, 10G, 25G, 40G, 100G, 400G)
• Device support and interoperability
• Optical isolation to prevent crosstalk between Tx and Rx signals Bestselling single-fiber BiDi solutions combine high performance, cost-effectiveness, and ease of deployment, making them ideal for campus networks, metro rings, data centers, and mobile transport networks.