The WDM or BIDI small form-factor pluggable (SFP) is a compact optical transceiver, module used in optical communications for both telecommunication and data bidirectional communications applications. It interfaces a network device mother board (for a switch, router or similar device) to a fiber optic or unshielded twisted pair networking cable. It is a popular industry format supported by several fiber optic component vendors. BIDI 1G optics are a small form factor pluggable module for Single Mode Fast Ethernet, Gigabit, Fiber Channel, SDH/SONET applications. In the industry there are several synonyms for Bidi optics, such as: Bi-directional optics, BX-D / BX-U, WDM, Single Fiber and so on. Specifically, the SFP-1G-BX-D and SFP-1G-BX-U for the 1G. BIDI SFP can be produced either with SC or LC simplex port, that is used both transmission and receiving. The most typical wavelength combination is 1310/1490, 1310/1550, 1490/1550 and 1510/1570. For a link you need 2 different optics, one that sends 1310nm and receives 1550nm and the other side of the fiber, which has a Bidi optic which sends 1550nm and receives 1310nm. In most cases these wavelengths are mentioned as Tx (transmitting) and Rx (receiving) on the label of the optic.   


Fiber Type  SMF or MMF  SMF or MMF  SMF or MMF
Data Rate Range Up to 2.67Gbps  up to 1.25G  4.25Gbps
Wavelength  1310 nm to 1550 nm  1310 nm to 1550 nm  1310 nm to 1550 nm
Optical Components (FP/PIN)/(DFB/PIN)  (FP/PIN)/(DFB/PIN)(DFB/APD) (FP/PIN)/(DFB/PIN)(DFB/APD)
Distance  Up to 80km or up to  35dB  Up to 60km or up to 36dB  Up to 40km or up to 24dB
Connector  LC/SC  LC/SC  LC
Case Temperature range  Com./Ind.  Com./Ind.  Com./Ind.
DDM  D   D  D

*- For more specific information for each module of these types, look in added catalog.

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