With the rapid development of new applications such as machine learning, artificial intelligence, virtual reality, and autonomous driving, internet data centers continue to expand in scale, placing growing demands on interconnect network bandwidth and latency.Traditional data center interconnect and metropolitan area networks  are facing unprecedented challenges.

The 400G ZR DWDM optical transceiver, as an innovative coherent pluggable optical solution, is revolutionizing how data centers connect. It enables high-speed data transmission over distances of up to 120 kilometers while significantly reducing cost and complexity.

01 Core Product Features

The 400G ZR DWDM optical transceiver adopts a QSFP-DD form factor and complies with the OIF 400 ZR Implementation Agreement (IA) standard. It supports a transfer rate of 400Gb/s, employs coherent optical technology and DP-16QAM modulation format, and operates in the C-band.

Designed for transmission over single-mode fiber, the transceiver can achieve a maximum transmission distance of 120 kilometers (when using EDFA optical amplifiers). Without amplifiers, the transmission distance is typically 30-40 kilometers.

Power consumption is a key factor in data center operating costs. The 400G ZR transceiver typically consumes ≤18W, with some models consuming as low as around 15W, significantly reducing system cooling requirements and fan power consumption.

The transceiver supports a duplex LC interface, with a tunable center wavelength range covering the C-band from 1528.77nm to 1567.13nm. It uses CFEC forward error correction technology and offers good dispersion robustness (2400ps/nm) and OSNR tolerance (26dB/0.1nm)

02 Technical Implementation Principles

The 400G ZR transceiver utilizes coherent optical communication technology, combining dense wavelength division multiplexing (DWDM) and high-order modulation techniques.

It uses dual-polarization 16-ary quadrature amplitude modulation (DP-16QAM) at a rate of approximately 60Gbaud, enabling 400Gb/s bandwidth on a single optical wavelength.

The transceiver integrates a Digital Signal Processor  employing advanced 7nm process technology for coherent detection and data processing. The DSP is responsible for FEC encoding/decoding, dispersion compensation, and polarization mode dispersion compensation.

The 400G ZR standard, developed by the Optical Internetworking Forum, ensures interoperability among multiple vendors. This means optical modules from different suppliers can be used in the same network, reducing the risk of vendor lock-in.

03 Diverse Application Scenarios

400G ZR optical transceivers are primarily used for Data Center Interconnect, supporting high-speed connections over distances of 80-120 kilometers between data centers in the same city. They enable distributed data centers to communicate with each other, share data, balance workloads, and provide backup.

In Metropolitan Area Networks, 400G ZR transceivers can connect data centers and network nodes distributed throughout a city. They provide backhaul solutions for 5G networks, supporting mobile backhaul by aggregating multiple 25Gb/s links.

The financial industry has extremely high requirements for low-latency networks. 400G ZR transceivers support low-latency financial networks for high-speed trading systems in securities and futures, enabling data synchronization for active-active data centers in the same city.

These transceivers are also suitable for edge computing networks, supporting intelligent dynamic networking between edge cloud nodes and meeting the fronthaul/midhaul/backhaul requirements in 5G carrier networks with CU/DU separation scenarios.

04 Significant Product Advantages

The 400G ZR solution offers significant cost advantages over traditional transmission systems. It eliminates the need for separate wavelength conversion boards, interfaces directly with wavelength division systems, and saves substantial costs for metropolitan internet data center interconnects.

Traditional wavelength division systems require multiple components such as optical wavelength conversion units, multiplexing/demultiplexing boards, optical amplifiers, and optical supervisory channels. In contrast, the 400G ZR solution simplifies the network architecture.

Switches output colored light directly through 400G-ZR mtransceivers, which is then multiplexed, amplified, and transmitted by the wavelength division system to the opposite end for demultiplexing, completing long-distance 400G transmission and greatly reducing network complexity.

The 400G ZR transceiver features a hot-pluggable form factor and supports direct use in switches, enabling IP over DWDM solutions and reducing network layers and the number of devices.

This solution supports smooth expansion and flexible upgrades. Network operators can expand network capacity on demand, upgrading gradually from 100G to 400G and even to 800G in the future, protecting existing investments.

400G QSFP-DD 80km ZR+ solution

The technological innovation of 400G ZR DWDM optical transceivers is driving upgrades to global digital infrastructure. With the explosive growth of AI, 5G, and IoT applications, the demand for high-speed, long-distance data transmission will only increase.

This technology not only provides a cost-effective interconnection solution for hyperscale data centers but also offers reliable connectivity for telecom operators, the financial industry, and edge computing.

In the coming years, as 800G ZR technology matures and is deployed, optical transmission capabilities will take another leap forward.