100G QSFP28 ER4 Optical Transceiver

The 100G QSFP28 ER4 Optical Transceiver is a 100Gbps long-reach optical module designed for transmission up to 40km over single-mode fiber. It uses four 25Gbps NRZ optical lanes with LAN-WDM technology around the 1310nm wavelength range and provides a duplex LC optical interface in a compact QSFP28 form factor.

1. What Is a 100G QSFP28 ER4 Optical Transceiver?

           

What is QSFP28 100G ER4 1310nm

100G QSFP28 ER4 is a well-defined technical standard specifying the optical module requirements for achieving a 100 Gbps data rate over SMF with a transmission distance of up to 40 kilometers.

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A 100G QSFP28 ER4 optical transceiver is a high-speed optical module designed for 100 Gigabit Ethernet connections requiring longer transmission distances than typical 100G short- and medium-reach modules. The module supports an aggregate data rate of up to 103.125Gbps and can provide transmission distances of up to 40km over single-mode fiber.

The ER4 architecture uses four optical wavelengths in the LAN-WDM range. The four optical channels are multiplexed into the fiber during transmission and separated back into individual electrical channels at the receiving end.

2. Key Features of 100G QSFP28 ER4

• 100Gbps aggregate data rate

• 4 × 25Gbps NRZ optical lanes

• Up to 40km transmission distance

• 1310nm LAN-WDM wavelength range

• QSFP28 form factor

• Duplex LC optical connector

• Single-mode fiber transmission

• LAN-WDM EML transmitter

• APD receiver

• Built-in TX and RX CDR

• Digital Diagnostic Monitoring (DDM)

• Maximum power consumption up to 5.5W

• Operating temperature from 0°C to 70°C

3. 100G QSFP28 ER4 Technical Specifications

4. How Does 100G QSFP28 ER4 Work?

The 100G QSFP28 ER4 module divides the electrical 100G signal into four 25Gbps channels. Each channel drives an individual LAN-WDM optical transmitter operating at a different wavelength within the 1310nm band.

The four optical signals are combined through an internal multiplexer and transmitted over a single-mode fiber link. At the receiving side, the optical signal is separated into four channels and converted back into electrical data through the receiver circuitry.

5. 4 × 25G NRZ Architecture

100G QSFP28 ER4 uses four optical lanes, with each lane operating at approximately 25Gbps using NRZ modulation. This architecture allows the module to deliver 100Gbps-class transmission while maintaining the widely adopted QSFP28 form factor.

The four-lane architecture also simplifies integration with 100G network equipment using CAUI-4 electrical interfaces.

6. 1310nm LAN-WDM Technology

LAN-WDM technology uses multiple closely spaced wavelengths within the 1310nm optical window. In a 100G ER4 module, four optical channels are used to carry the 100G signal.

This wavelength multiplexing approach enables four optical channels to share one fiber pair, making ER4 suitable for long-distance 100G connections without requiring four independent fiber pairs.

7. 40km Transmission Over Single-Mode Fiber

The 100G QSFP28 ER4 is designed for links of up to 40km over single-mode fiber. The longer reach makes it suitable for network connections where standard short-reach 100G modules cannot provide sufficient transmission distance.

Actual link performance depends on fiber attenuation, connector loss, dispersion, optical power, receiver sensitivity, and the characteristics of the connected network equipment.

8. EML Transmitter and APD Receiver

The transmitter uses LAN-WDM EML technology to generate stable optical signals across the required wavelength channels. EML technology is well suited to higher-speed optical transmission where wavelength stability and signal quality are important.

The receiving side uses an APD receiver designed to provide higher sensitivity for longer optical links. The combination of EML transmitters and APD receivers supports the extended transmission requirements of the ER4 application.

9. Duplex LC Optical Interface

The module uses a duplex LC optical connector for the single-mode fiber connection. One fiber is used for transmission and the other for reception.

The LC interface is widely used in data center, telecom, enterprise, and metro network environments, making the 100G QSFP28 ER4 easy to integrate with existing LC-based fiber infrastructure.

10. QSFP28 Form Factor

The QSFP28 form factor provides a compact solution for 100G network equipment. Compared with earlier generations of larger optical module packages, QSFP28 enables higher port density while maintaining the electrical and optical interfaces required for 100G networking.

This makes 100G QSFP28 ER4 suitable for high-density switches, routers, transport equipment, and other network platforms.

11. Power Consumption and Thermal Performance

The C-LIGHT 100G QSFP28 ER4 has a maximum power consumption of up to 5.5W at the specified operating temperature. Power consumption is an important consideration when deploying large numbers of 100G optical modules in high-density network equipment.

The module operates from 0°C to 70°C, making it suitable for standard commercial-temperature data center and network environments.

12. Digital Diagnostic Monitoring

Digital Diagnostic Monitoring (DDM) allows compatible network equipment to monitor important operating parameters of the optical module. These diagnostic functions can help network operators check module status and identify potential optical or thermal issues.

DDM is particularly useful in long-distance 100G links because optical performance can have a direct impact on link stability.

13. 100G QSFP28 ER4 Applications

100G QSFP28 ER4 is designed for applications requiring high bandwidth and extended optical reach, including:

• Data Center Interconnect (DCI)

• Metropolitan Area Network (MAN) backbone

• 5G transport networks

• Enterprise core networks

• Long-distance Ethernet connections

• Carrier network infrastructure

• High-speed router and switch interconnections

14. 100G ER4 vs Other 100G Optical Modules

100G ER4 is positioned for longer-reach applications within the 100G optical transceiver family. Compared with shorter-reach modules such as SR4 and LR4, ER4 is designed for significantly longer fiber connections.

The appropriate module should be selected according to transmission distance, fiber type, connector configuration, network equipment compatibility, optical budget, and deployment requirements.

15. 100G QSFP28 ER4 Compatibility

Before deployment, compatibility between the optical transceiver and the host switch, router, or other network equipment should be verified. Important factors include QSFP28 support, electrical interface requirements, module coding, optical specifications, operating temperature, and supported network protocols.

For large-scale deployments, compatibility testing with the target network platform is recommended before production installation.

16. 100G QSFP28 ER4 for Data Center Interconnect

Data Center Interconnect applications often require higher bandwidth over distances beyond the typical reach of intra-data-center optical links. The 40km reach of the 100G QSFP28 ER4 makes it suitable for connecting data centers, campus facilities, and metro network nodes over single-mode fiber.

Its QSFP28 form factor also allows high-density 100G interfaces to be deployed in switches and routers without requiring large optical module packages.

17. Why Choose 100G QSFP28 ER4?

100G QSFP28 ER4 combines 100Gbps transmission, extended 40km reach, LAN-WDM technology, and a compact QSFP28 package. It provides a practical option for network operators that need to extend 100G connectivity beyond typical short- and medium-reach deployments.

For applications involving DCI, metro networks, enterprise core networks, and long-distance Ethernet connectivity, ER4 provides a balance between transmission distance, port density, and optical performance.

18. C-LIGHT 100G QSFP28 ER4 Solution

C-LIGHT provides the CL100GQSFPER4 100G QSFP28 ER4 optical transceiver for 40km single-mode fiber applications. The module uses a QSFP28 package, LAN-WDM EML transmitters, APD receivers, duplex LC connectivity, and DDM support.

The solution is designed for data center interconnect, metro networks, 5G transport, enterprise networks, and other 100G long-distance connectivity applications.

19. Conclusion

The 100G QSFP28 ER4 Optical Transceiver is a long-reach 100G solution for network links requiring transmission distances of up to 40km over single-mode fiber. With 4 × 25G NRZ lanes, LAN-WDM technology, EML transmitters, APD receivers, duplex LC connectivity, and QSFP28 packaging, it provides a compact option for DCI, metro, telecom, and enterprise network deployments.

20. Frequently Asked Questions