400G QSFP-DD optical transceiver — 8 lanes of 50G PAM4 modulation in the QSFP-DD form factor (1.5× the depth of QSFP28 with backward compatibility for QSFP+ / QSFP28 modules at lower rates). CMIS 5.0+ firmware, integrated thermal management for the 12 W power envelope.
Reach variants: DR4 (500 m / SMF via MPO-12 single-fiber), DR4+ (2 km), FR4 (2 km / duplex LC via CWDM wavelengths), LR4 (10 km / duplex LC via LAN-WDM), ER8 (40 km), and ZR / ZR+ coherent (80–120 km with dual-polarization modulation). 2× FR4 breakout to 2× 200G FR4 is also stocked.
Programmed for Cisco IOS XR / NX-OS, Arista EOS, Nvidia Spectrum-3 / Quantum-2, Juniper Junos, and Mellanox MLNX-OS coding. Every module is DDM / DOM enabled with full I²C diagnostics, integrated heatsink, and EMI shielding. Common deployments include datacenter spine fabrics, AI training cluster spines, supercomputing interconnect, and 400G metro / DCI long-haul transport.
