When selecting optical transceivers for your network infrastructure, understanding the difference between a standard SFP module and a BiDi SFP module is crucial for optimizing fiber usage and deployment costs. Both are hot-pluggable fiber optic transceivers, but they operate on fundamentally different principles.

What is a Standard SFP Transceiver?

As we learned, a common SFP transceiver is generally with two ports, one is TX port to transmit the signal, and the other one is RX port to receive signals. This means a standard SFP optical module requires two strands of fiber to establish a full-duplex connection—one for transmitting and one for receiving.

What is a BiDi SFP Transceiver?

BiDi SFP transceiver is only with one port which uses an integral WDM coupler to transmit and receive signals over a single strand fiber.BiDi, short for Bidirectional, is a specialized BiDi optical module that leverages Wavelength Division Multiplexing (WDM) technology to combine transmit and receive signals onto a single fiber core, effectively doubling the capacity of existing fiber infrastructure.

For BiDi SFPs (Single-Fiber):

Since BiDi SFP transmits and receives signals with different wavelengths, we should connect the two BiDi SFPs which have the opposite wavelength together. For example, we use a TX1310/RX1550nm BiDi SFP at one end, then we must use a TX1550/RX1310nm BiDi SFP on the other end (shown in the figure below). This single-fiber SFP configuration enables bidirectional communication over one fiber strand.

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