200G QSFP56 FR4 CWDM4 2km Duplex LC

The 200G QSFP56 FR4 optical transceiver delivers 200Gbps Ethernet connectivity over single-mode fiber at distances up to 2km, using 4 lanes of 53.125Gbps PAM4 (26.5625 GBaud per lane) multiplexed onto CWDM wavelengths of 1271nm, 1291nm, 1311nm, and 1331nm through a duplex LC connector. Each optical lane uses an EML (Electro-absorption Modulated Laser) paired with a PIN photodetector, chosen for the chirp and dispersion performance CWDM4 reach requires at 2km.

The module is fully compliant with QSFP MSA and IEEE 802.3bs, and manages link health via CMIS 5.2 (or later) over I2C, exposing per-lane transmit/receive optical power, bias current, module temperature, and supply voltage for real-time diagnostics. It's well suited for data center interconnects, enterprise storage fabrics, and campus backbone links where 200G needs to travel further than multimode SR4 reach allows.