100G BiDi QSFP28 LR1 20km Transceiver (Side B): BIDI-100G-Q28-SL20B

EdgeOptic's BIDI-100G-Q28-SL20B is a 100G BiDi QSFP28 module built on a single-fiber, single lambda BiDi design (one dedicated wavelength per transmit/receive direction, as opposed to multi-wavelength WDM BiDi variants), with 20km reach over single-mode fiber and a single LC/UPC connector. This quad small form-factor pluggable transceiver uses PAM4 line coding on one optical lane per direction, delivering 106.25 Gbps for 100 Gigabit Ethernet applications in metro network and data center interconnect deployments.

This Side B module transmits at 1310nm and receives at 1291nm on the same fiber strand, one dedicated wavelength per direction, the single lambda bidirectional pairing that lets one strand carry both directions of a 100G link on its two wavelengths. The transmitter is an EML laser and the receiver is a PIN photodiode, with integrated CDR to hold signal integrity at PAM4 data rates. FEC is integrated in the module's DSP, needed for PAM4 to detect and correct bit errors across the 20km link.

The module carries a 9.8 dB average optical link budget, which sets the maximum reach on a given fiber plant. Over standard single-mode fiber this supports links up to 20 kilometers, though actual reach depends on installed fiber attenuation, splice count, and connector losses on the specific route, so 20km is an indicative planning distance, not a fixed guarantee. This reach follows the 100G Lambda MSA's 100G-LR1-20 reach class convention for single lambda BiDi optics.

BIDI-100G-Q28-SL20B is a hot-pluggable QSFP28 module with a single LC/UPC optical connector. Its electrical interface conforms to IEEE 802.3cd, CAUI-4, and SFF-8679, so it works with standard QSFP28 host cages. The LR1 designation here refers to the 100G Lambda MSA reach class convention for 20km single lambda BiDi optics, not an IEEE-defined bidirectional PMD. IEEE 802.3cu's 100GBASE-LR1 clause covers a different, duplex two-fiber interface.

Digital diagnostic monitoring (DDM/DOM) reports transmitted and received optical power, module temperature, bias current, and supply voltage in real time. Integrated FEC inside the DSP corrects bit errors introduced across the fiber, which PAM4 signaling depends on for the extended 20km reach. The module operates from 0 to 70 degrees Celsius, draws a maximum of 4.5W at plus 3.3V, and stores between negative 40 and 85 degrees Celsius.

Compliance covers IEEE 802.3cd, CAUI-4, and SFF-8679 for the electrical interface, plus CE and RoHS certification.

BiDi transceivers must be deployed in matched pairs with wavelength-complementary transmit and receive plans. This Side B module transmits at 1310nm and receives at 1291nm, so it must connect to a Side A module, BIDI-100G-Q28-SL20A, built with a transmit of 1291nm and a receive of 1311nm on the same 20km link. Each receiver carries a 20nm RX wave bandwidth, so this Side B module's 1310nm transmit falls within the Side A receiver's passband, and Side A's 1291nm transmit falls within this Side B module's receiver passband. Two Side B modules will not link, since both transmit at 1310nm and listen near 1291nm. Pairing this 20km Side B module with a 10km Side A or Side B module will not work either, because the 10km pair runs its own wavelength plan. Order the matching 20km Side A module for this link.

Typical applications include metro network connections, data center interconnects, and campus backbone links where fiber conservation and 20km reach are both required.

The BIDI-100G-Q28-SL20B ships with a lifetime warranty. For project-quantity pricing or paired Side A ordering guidance, contact our sales team.