100G BiDi QSFP28 LR1 20km Transceiver (Side A): BIDI-100G-Q28-SL20A

EDGEOPTIC's BIDI-100G-Q28-SL20A is a 100G BiDi QSFP28 LR1 20km transceiver built for single lambda bidirectional 100 Gigabit Ethernet over single-mode fiber. The module uses PAM4 encoding on one optical lane per direction, delivering 106.25 Gbps over a single fiber strand instead of the duplex fiber pair a standard QSFP28 optic requires. It targets metro network and data center interconnect links where fiber conservation and extended reach both matter, and it can be coded for compatibility across multiple vendor platforms.

This Side A module transmits at 1291nm and receives at 1311nm on the same fiber, using single lambda BiDi architecture. It uses an EML (Electro-absorption Modulated Laser) transmitter and a PIN photodiode receiver, with integrated CDR (Clock and Data Recovery) to maintain signal integrity at PAM4 data rates. The design covers 100G Ethernet PAM4 (106.25 Gbps) applications only; it does not support Fibre Channel or OTN framing.

The average optical link budget is 9.8 dB, which sets the maximum usable reach. Over standard single-mode fiber this supports distances up to 20 kilometers; actual reach in a given deployment depends on installed fiber attenuation and connector losses, so treat the 20km figure as an indicative rating rather than a guarantee. The LR1 20km designation follows the 100G Lambda MSA-style reach-class naming convention used for single lambda BiDi optics. It is not the IEEE 802.3cu 100GBASE-LR1 physical layer specification, which defines a duplex, two-fiber interface at 1310nm; no IEEE clause defines a 20km single-fiber BiDi PMD.

The BIDI-100G-Q28-SL20A is a hot-pluggable QSFP28 module with a single LC/UPC connector as its optical interface. Its electrical interface follows IEEE 802.3cd, CAUI-4, and SFF-8679, so it works with standard QSFP28 host cages. The transceiver can be programmed with vendor-specific EEPROM coding, letting the same hardware register correctly across multiple network equipment brands.

DDM/DOM (Digital Diagnostic Monitoring) reports transmitted and received optical power, module temperature, bias current, and supply voltage in real time. Forward Error Correction is integrated in the DSP, which is required for reliable PAM4 detection over the extended 20km reach. The module operates from 0 to 70°C and draws a maximum of 4.5W at +3.3V, with a storage range of -40 to 85°C.

Compliance covers CE, RoHS, IEEE 802.3cd, CAUI-4, and SFF-8679.

BiDi modules must be deployed in matched pairs with complementary wavelength configurations. This Side A module transmits at 1291nm and receives at 1311nm. Its counterpart, the Side B module BIDI-100G-Q28-SL20B, transmits at 1310nm and receives at 1291nm. Each side carries a 20nm RX wave bandwidth, so the partner's transmit wavelength falls within the receiver's passband on both ends. Verify both ends of the link match during commissioning; pairing two Side A (or two Side B) modules on the same fiber prevents the link from establishing.

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

Every BIDI-100G-Q28-SL20A ships with a lifetime warranty. For project quantities or vendor-specific EEPROM coding, contact our sales team.