400G / 800G Fiber Optic Transceivers

400G and 800G transceivers represent the leading edge of optical networking, designed for hyperscale data centers, AI training clusters, and cloud backbone links. Form factors at this tier include QSFP-DD (Quad Small Form-factor Pluggable Double Density, 400G), OSFP (Octal Small Form-factor Pluggable, 400G/800G), and QSFP112 (400G using 4×100G lanes).

What is QSFP-DD? QSFP-DD adds a second row of electrical contacts to the QSFP form factor, doubling the lane count to 8×50G for 400G total. What is OSFP? OSFP (Octal Small Form-factor Pluggable) is a larger module with 8 electrical lanes — 8×50G for 400G or 8×100G for 800G — providing better thermal headroom for high-power coherent optics than QSFP-DD. What reach options are available? DR4 (500 m on SMF, 4-fiber parallel), FR4 (2 km, 4-wavelength WDM), LR4 (10 km), SR8 (100 m on OM4), and CR8 (passive copper, 3 m).

Are 400G transceivers compatible with existing infrastructure? QSFP-DD is backward compatible — a QSFP-DD cage accepts QSFP28 (100G) and QSFP+ (40G) modules. QSFP-DD to 8×SFP+ (8×10G), 4×QSFP28 (4×100G), and 2×QSFP28 (2×100G) breakout cables enable phased migration.

400G is the current deployment standard in hyperscale data centers at companies like AWS, Meta, Google, and Microsoft. For AI/ML workloads, 400G and 800G optics connect NVIDIA H100/H200 GPU clusters via NVIDIA Quantum-2 InfiniBand (NDR 400G) and Ethernet switches. Industrial-grade versions support military communications, energy grid SCADA, and high-reliability telecom applications.

400G / 800G Transceivers — Full Catalog

C = Commercial (0°C to 70°C) · I = Industrial (−40°C to 85°C)