400G QSFP-DD optical transceivers, also known as 400G QSFP-DD optical modules, are mainstream high-speed 400GbE optics designed for next-gen data center networking, AI HPC clusters and hyperscale data center interconnect (DCI). This complete product line covers short-range intra-rack links, medium-reach campus interconnections, metro long-distance links and ultra-long haul inter-city transmission, fully compliant with QSFP-DD MSA, IEEE 802.3bs and CMIS4.0 global industry standards.

All 400G QSFP-DD optical modules adopt 4×100Gbps PAM4 optical lanes paired with 8×53.125Gbps PAM4 electrical interfaces, delivering up to 425Gbps aggregate bandwidth to support full-speed 400GbE data forwarding. The full lineup includes direct-modulated PAM4 transceivers (max power ≤12W) and coherent 400G ZR4 ultra-long reach optical transceivers (max power ≤19W), with single 3.3V low-voltage power supply built-in.

Equipped with I2C CMIS-compliant DDM digital diagnostic monitoring, each 400G QSFP-DD transceiver tracks real-time optical power, operating temperature, supply voltage and laser bias current. Connector options include MPO array and duplex LC, compatible with OM4 multimode fiber (MMF) and OS2 single-mode fiber (SMF). Available reach variants cover 100m SR8, 500m DR4, 2km FR4, 10km LR4, 40km ER4 and 80km coherent ZR4. Every 400G optical transceiver passes RoHS, REACH and IEC60825-1 Class 1 laser safety certification, operating reliably 24/7 within 0°C~70°C commercial temperature range, widely deployed in AI HPC clusters, cloud hyperscale IDC, metro DCI and carrier DWDM backbone networks.

1. Full-reach 400G optical transceiver portfolio for one-stop data center fiber link selection
Complete range of industry-standard 400G QSFP-DD modules: 100m MMF SR8 short-reach optics, 500m DR4 intra-data center transceivers, 2km FR4 & 10km LR4 campus backbone modules, 40km ER4 metro optics and 80km coherent ZR4 ultra-long haul transceivers. All 400GbE QSFP-DD optics work seamlessly with mainstream network switches and GPU servers without third-party optical hardware.
2. Standard QSFP-DD double density form factor, hot-pluggable with 4x100G breakout support
The QSFP-DD double-density package doubles front-panel port density compared to legacy transceivers, supporting 400G breakout into four independent 100G lanes. Hot-swap design enables non-stop data center capacity expansion, cutting cabling and network upgrade costs for leaf-spine switch architectures.
3. Dual optical architectures for short-reach direct PAM4 & long-distance coherent DCI
- Direct PAM4 transceivers (SR8/DR4/FR4/LR4/ER4): Cost-effective, low-power 400G optical modules for intra-data center and campus 400GbE interconnections;
- Coherent 400G ZR4 ultra-long haul transceiver: Integrated DSP coherent demodulation delivers superior fiber attenuation and dispersion tolerance, supporting 80km transmission without external optical amplifiers, ideal for inter-city DCI and carrier DWDM backbone links.
4. CMIS DDM intelligent monitoring to simplify automated IDC operation & maintenance
All 400G QSFP-DD optical transceivers support standard CMIS DOM digital diagnostics, allowing remote real-time parameter reading and rapid link fault identification, fully compatible with automated data center O&M platforms to reduce manual inspection workload.
5. Stable, globally compliant optics with multi-switch compatibility & OEM customization
Optimized thermal design ensures consistent performance under 0~70°C rack operating conditions. Lead-free eco-friendly manufacturing meets global IDC and carrier compliance standards. Custom wavelength, reach and private OEM labeling are available, with full compatibility testing for Cisco, Huawei, H3C, Arista and domestic open network switches.

Industry Standard Model No.	Short Description	Rate	Wavelength	Fiber & Transmission Reach	Connector	Typical Application
QSFP-DD-400G-SR8	400G QSFP-DD SR8 Optical Module	400G	850nm	OM4 MMF, 100m	MPO-16	Short-range 400G interconnection for TOR switches & GPU servers
QSFP-DD-400G-DR4	400G QSFP-DD DR4 Transceiver	400G	1310nm	SMF, 500m	MPO-12	Intra-data center rack-to-rack medium-reach 400G links
QSFP-DD-400G-FR4	400G QSFP-DD FR4 Optics	400G	CWDM4	SMF, 2km	Duplex LC	Multi-building campus & inter-floor 400G backbone links
QSFP-DD-400G-LR4	400G QSFP-DD LR4 Optical Module	400G	CWDM4	SMF, 10km	Duplex LC	Campus backbone & small-scale same-city DCI interconnections
QSFP-DD-400G-ER4	400G QSFP-DD ER4 Long Reach Transceiver	400G	LWDM 1310nm	OS2 SMF, 40km	Duplex LC	Metro edge nodes & same-city multi-site 400G DCI networks
QSFP-DD-400G-ZR4	400G QSFP-DD Coherent ZR4 Ultra-Long Haul Module	400G	C-band DWDM	OS2 SMF, 80km	Duplex LC	Inter-city DCI & carrier 400G metro DWDM backbone networks

1. AI & HPC High-Performance Computing Clusters
Low-latency 400G uplinks between GPU compute servers and leaf-spine switches. Cost-efficient SR8 and DR4 short-reach 400G QSFP-DD optical modules reduce fiber cabling expenses in AI training racks.
2. Hyperscale Cloud IDC & 400G Data Center Network Upgrade
TOR-Spine standard network architecture and distributed storage bandwidth expansion. FR4 and LR4 transceivers support 2km~10km campus backbone fiber, reusing existing LC single-mode cables to minimize data center reconstruction costs.
3. Same-City Data Center Interconnect (DCI) Networks
40km ER4 long-reach optical transceivers for intra-metro campus links; 400G ZR4 coherent ultra-long haul modules deliver 80km repeater-free transmission for cross-district carrier DCI, eliminating costly optical amplifiers.
4. Carrier Metro DWDM & Enterprise 400G Core Backbone Networks
Smooth network upgrade from legacy 100G to high-capacity 400G backbone. Coherent 400G ZR4 optical transceivers are fully compatible with existing DWDM systems to support long-distance 400GbE carrier transmission.
5. Large Enterprise Campus & Multi-Branch Financial Networking
Unified 400G high-speed transmission architecture covering rack, building and cross-city branch interconnections. One full portfolio of 400G QSFP-DD optics meets all fiber link demands and simplifies bulk network procurement.

1. Free downloadable resources: Full datasheets, official test reports, 3D drawings and multi-brand switch compatibility matrix for all 400G QSFP-DD optical transceivers;
2. Free sample testing for all reach variants of 400G optical modules, customized wavelength, transmission distance and private OEM labeling available;
3. 24/7 global optical communication technical support, reliable product warranty and stable fast mass delivery for overseas bulk orders;
4. Compatibility customization and testing for mainstream switches including Cisco, Huawei, H3C, Arista, plus domestic open-source network hardware.