CFP2-DCO vs QSFP-DD DCO vs OSFP-DCO：What's the Difference?

Coherent Module Introduction

In the field of coherent optical communication, coherent modulation and heterodyne detection technologies play a crucial role, and coherent optical modules are the primary products based on these technologies. Coherent modules such as CFP2-DCO, QSFP-DD DCO, and OSFP-DCO typically include coherent optical receivers and digital signal processors (DSPs), possessing the flexibility to adapt to different optical network environments. They contribute actively to the construction of efficient and reliable optical communication infrastructure.

Figure 1: Coherent Module Components

Facilitators of Coherent Module Development

Drive for Technical Innovation

As the demand for data transmission capacity continues to increase, the challenges of signal attenuation and distortion in long-distance transmission become more apparent. Advanced coherent optical technology has emerged to address these challenges, leveraging the phase and amplitude information of light waves for communication. In comparison to traditional techniques, coherent modules like CFP2-DCO, QSFP-DD DCO, and OSFP-DCO adopt this unique transmission approach, successfully overcoming limitations, particularly excelling in long-distance transmissions, and maintaining a high level of signal quality.

Figure 2: Coherent Optical Communication

Growing Data Demands

In the era of digitization, cloud computing, and big data, the demand for data transmission capacity is surging. High-performance coherent modules, evolving from CFP to CFP2, QSFP-DD, OSFP, and more, swiftly meet the growing needs for high-capacity data transmission. This evolution not only conserves optical bandwidth but also enhances the efficiency of fiber transmission, making coherent modules an excellent choice for boosting transmission bandwidth.

Figure 3: Global Mobile Data Traffic Forecast

CFP2-DCO vs QSFP-DD DCO vs OSFP-DCO

CFP2-DCO

In the field of optical communication, the CFP2-DCO stands out as a high-performance coherent module. It not only adopts the CFP2 standard design but also successfully meets the high requirements for speed and flexibility, even with its relatively larger form factor. Particularly noteworthy is the "DCO" in the name CFP2-DCO, representing "Digital Coherent Optics." This module integrates coherent optical receivers and digital signal processors (DSPs), supporting high-capacity data transmission. Widely applied in critical areas such as data center interconnects, metropolitan area networks, and long-distance transmissions, it provides essential technological support for meeting the demands of modern communication.

The following are the main advantages of the CFP2 module：

• This module achieves breakthroughs not only in width and power consumption provided by the CFP2 standard but also significantly enhances performance compared to traditional CFP.

• It actively responds to the requirements of metropolitan and access networks, optimizing the total cost of ownership (TCO) through comprehensive savings in power consumption and density, delivering clear economic value to users.

Figure 4: FS CFP2-DCO Coherent Module

QSFP-DD DCO

QSFP-DD DCO is an advanced coherent module following the QSFP-DD standard, characterized by a double-density compact form factor aiming to provide higher port density. Integrating coherent optical receivers and a digital signal processor, it supports high-speed and highly customizable data transmission. The compact design of QSFP-DD DCO makes it especially well-suited for optical communication applications with high port density requirements.

The following are the main advantages of the QSFP-DD module：

• In modern data centers and other confined spaces, the QSFP-DD DCO module, compared to CFP2-DCO and OSFP-DCO modules, is smaller, consumes less power, and offers greater flexibility, providing more versatile deployment options.

• Applications of QSFP-DD DCO are more common in the 400G optical transceiver market, with the ZR and 400G ZR+ optical modules gaining attention. The 400G ZR module, in DD-QSFP form factor, is designed for large data centers and point-to-point networks, providing high-bandwidth interconnections in a standard package. It achieves speeds exceeding 400GB/s over distances beyond 120km. The 400ZR+ combines OIF and OpenROADM standards, supporting high-performance pluggable modules for multi-vendor interoperability, particularly in DWDM 400G applications.

OSFP-DCO

OSFP-DCO is designed to meet the demands of high bandwidth and data rates, adhering to the OSFP standard. Integrating coherent optical receivers and a digital signal processor, OSFP-DCO possesses the capability to adapt to different optical network environments. It plays a crucial role in supporting long-distance transmissions and high-speed optical communication systems.

The following are the main advantages of the OSFP module：

• Compared to the QSFP-DD DCO and CFP2-DCO, the OSFP-DCO is able to provide greater bandwidth using the OSFP standard design, which makes it suitable for scenarios with high bandwidth requirements.

• The OSFP-DCO module uses a pluggable OSFP form factor and 7nm DSP technology to support transmission speeds of up to 100/400Gbps. OSFP-DCO is more widely used in various application scenarios such as metro carrier, access and cloud/DCI.

Figure 5: FS QSFP-DD Coherent Module

Main Types of FS 200G & 400G Coherent Transceiver

The following table presents the specific parameters of the FS 200G/400G coherent optical modules．

Conclusion

In conclusion, CFP2-DCO, QSFP-DD DCO, and OSFP-DCO optical transceivers play pivotal roles in the realm of coherent modules, each exhibiting unique advantages in specific scenarios and applications. The selection of an appropriate coherent module depends on specific network requirements, scene demands, and performance expectations. Looking ahead, as technology continues to advance, these coherent modules will persist in playing a vital role in optical communication, providing crucial support for connectivity in the digital era. This will propel the ongoing evolution of optical communication technology to meet the escalating demands of networks.