400G optical module is an advanced product in the field of high-speed transmission nowadays, which is widely used in high-performance data centers, communication networks, large-scale computing, cloud computing and other fields. This article will introduce in detail the definition, technology, product models, application scenarios and future development direction of 400G optical modules.

I. What is 400G optical module?

400G optical module refers to the optical module products with transmission rate up to 400Gbps. The current mainstream package type is QSFP-DD (Quad Small Form-factor Pluggable Double Density), which is a high-speed optical module interface specification, an upgraded version of QSFP interface, supporting 400G high-speed transmission. Using optical fiber as the signal transmission medium, by converting the digital signal into optical signal and transmitting it in the fiber.

2, 400G optical module technology

The technology of 400G optical module mainly includes PAM4 modulation technology, COB packaging technology, DSP digital signal processing technology, microwave integrated circuit technology, high-speed electrical interface technology, etc.

PAM4 modulation technology is the core technology of 400G optical module to realize high-speed transmission, which adopts 4-stage pulse amplitude modulation to extend the traditional 2-decimal digital signal modulation to 4-stage and realize the 400G transmission rate.

COB packaging technology is a new type of packaging technology, which uses chips directly welded on the substrate without using the packaging shell, which can achieve higher signal transmission rate and smaller size.

DSP digital signal processing technology is a technology used in 400G optical modules to achieve signal processing and decoding, which can modulate, demodulate and error-correct the optical signal and other operations to improve the transmission rate and signal quality of the optical module.

Microwave integrated circuit technology is a high frequency circuit design technology that can integrate multiple circuits on a single chip to achieve high speed, low power consumption and small size high frequency circuit design.

High-speed electrical interface technology is a technology for connecting 400G optical modules with external devices, which includes various different interface types, such as QSFP-DD, OSFP, etc., used to realize the connection and data transmission between different devices.

3, the product model classification of 400G optical module

According to different specifications and interface types, the product model classification of 400G optical module mainly includes several types such as SR8, DR4, FR4, LR4, LR8 and ER4.

Among them, SR8 is suitable for short distance data transmission, DR4 for medium distance data transmission, FR4 for long distance data transmission, LR4 for ultra-long distance data transmission, LR8 for longer distance data transmission, and ER4 for very long distance data transmission.

The above are the more common 400G optical module product models in the market, with the continuous development of technology, more new models may emerge in the future.

4, Application scenarios of 400G optical module

400G optical module is suitable for operators' broadband access, broadband network, data center interconnection, cloud computing and other fields. In the data center, with the development of cloud computing and big data technology, the requirements for scalability, reliability and low latency of data center are getting higher and higher, and 400G optical module can meet these requirements. In addition, 400G optical modules are also suitable for high-speed transmission and long-distance transmission scenarios.

5, Future Development Direction of 400G Optical Module

With the increasing demand from data centers, enterprise networks and telecom operators, the 400G optical module market will continue to grow. As technology continues to advance, the cost of 400G optical modules will continue to decline, while performance will continue to improve. In the future, the application scenarios of 400G optical modules will be further expanded, including IoT, 5G and other fields.