800G QSFP-DD 2FR4 2km optical transceiver

The C-LIGHT 800G QSFP-DD 2FR4 2km optical transceiver is a high-speed optical module designed for high-bandwidth data center and Ethernet networking applications. The CL800GQDD2FR4-CS supports 2x400GBASE-FR4 optical interfaces and 8x100GBASE-FR1 host applications, providing an 800G-class connectivity solution over single-mode fiber.

Designed in the QSFP-DD800 form factor, the module features a dual CS connector, EML laser technology, PAM4 signaling, and an operating case temperature of 0°C to 70°C. It is suitable for high-density network equipment that requires high-speed optical connectivity and flexible 400G/100G breakout options.

1. 800G QSFP-DD 2FR4 Optical Transceiver Overview

The CL800GQDD2FR4-CS is an 800G QSFP-DD optical transceiver based on a 2x400GBASE-FR4 architecture. It provides two 400G optical interfaces and supports 8x100GBASE-FR1 host applications, making it suitable for high-density Ethernet and data center networking.

The module uses single-mode fiber and four LAN-WDM wavelength ranges for each optical group. Its QSFP-DD800 form factor enables high-density deployment in next-generation 800G switches and networking platforms.

2. Key Features

• 800G-class data rate

• 2x400GBASE-FR4 optical interface

• 8x100GBASE-FR1 application support

• 2x400GAUI-4 C2M electrical interface

• QSFP-DD800 MSA HW Rev 6.01 Type 2A compliant

• Dual CS optical connector

• EML laser source

• Single-mode fiber

• CMIS Rev 5.0 compliant

• Operating case temperature: 0°C to 70°C

• Two-wire serial interface with digital diagnostic monitoring

• RoHS compliant

• Class 1 laser

3. 2x400GBASE-FR4 Optical Architecture

The 800G QSFP-DD 2FR4 module integrates two 400GBASE-FR4 optical interfaces within a single QSFP-DD800 package. This architecture provides high aggregate bandwidth while maintaining a compact pluggable form factor.

On the electrical side, the module supports 2x400GAUI-4 C2M. On the optical side, the two 400G FR4 groups use four wavelength channels each, creating an eight-lane optical architecture.

4. LAN-WDM Wavelengths

The optical transmitter and receiver use four LAN-WDM wavelength ranges. The specified center wavelengths are 1271nm, 1291nm, 1311nm, and 1331nm.

5. PAM4 Optical Performance

The module is designed for high-speed PAM4 optical transmission. According to the product specification, the maximum TDECQ for each lane is 3.4dB and the maximum TECQ is also 3.4dB.

The transmitter extinction ratio is specified at a minimum of 3.5dB, while the maximum transmitter transition time is 17ps. These specifications support the high-speed signaling requirements of 800G-class optical networking.

6. Transmitter Optical Specifications

7. Receiver Optical Specifications

The receiver section supports the same four LAN-WDM wavelength groups used by the transmitter. The average receive power for each lane is specified from -7.2dBm to 4.4dBm, while the receiver damage threshold is 5.4dBm per lane.

8. QSFP-DD800 Form Factor

The CL800GQDD2FR4-CS uses the QSFP-DD800 form factor, which is designed for high-density 800G networking equipment. The module supports 2x400GAUI-4 C2M electrical connectivity and uses a dual CS optical connector.

The compact QSFP-DD800 design allows network equipment manufacturers to deploy high-bandwidth optical connectivity while maintaining efficient port density in 800G switches and data center platforms.

9. Dual CS Connector

The module uses a dual CS connector in accordance with the QSFP-DD800 MSA HW Rev 6.01 Type 2A specification. The dual CS configuration corresponds to the module's dual 400G optical architecture and provides a high-density optical interface for the 800G module.

10. 8x100GBASE-FR1 Support

In addition to its 2x400GBASE-FR4 application, the CL800GQDD2FR4-CS supports 8x100GBASE-FR1. This provides additional flexibility for network architectures that require 100G connectivity and breakout configurations.

The combination of 800G aggregate bandwidth and 8x100GBASE-FR1 support makes the module suitable for high-density switching environments where different network speeds may need to coexist.

11. Standards and Management

The CL800GQDD2FR4-CS is designed according to major industry specifications for high-speed optical networking. It complies with IEEE 802.3cu-2021 for the 2x400GBASE-FR4 optical interface and IEEE P802.3ck D3.0 for the 2x400GAUI-4 C2M electrical interface.

The module also complies with QSFP-DD800 MSA HW Rev 6.01 Type 2A with a dual CS connector and CMIS Rev 5.0. A two-wire serial interface provides digital diagnostic monitoring for module management and operational monitoring.

12. Operating Temperature and Reliability

The specified case operating temperature of the CL800GQDD2FR4-CS is 0°C to 70°C. The module is also RoHS compliant and uses a Class 1 laser, supporting deployment in standard data center networking environments.

13. Applications

• 800G Ethernet networks

• AI data center networking

• GPU cluster interconnects

• High-performance computing networks

• Data center switch connectivity

• High-density data center networks

• Cloud computing infrastructure

• 400G and 100G breakout applications

14. Why Choose C-LIGHT 800G QSFP-DD 2FR4?

The C-LIGHT CL800GQDD2FR4-CS combines an 800G-class data rate with a compact QSFP-DD800 form factor and dual CS optical interface. Its 2x400GBASE-FR4 architecture provides a practical solution for high-density Ethernet and data center networks.

Support for 8x100GBASE-FR1 also gives the module greater flexibility for network architectures that require 100G breakout connectivity. With EML laser technology, PAM4 signaling, single-mode fiber support, digital diagnostics, and compliance with major industry standards, the module is designed for next-generation high-speed optical networking.

800G-QSFP-DD-2FR4-CS-2km.pdf

15. Frequently Asked Questions