Data Center Optical Transceivers & DAC/AOC/AEC Solutions

With the rapid development of artificial intelligence (AI), large-scale model training, high-performance computing (HPC), and cloud data centers, data center networks are accelerating their evolution from the traditional 100G/200G era toward 400G, 800G, and even 1.6T high-speed interconnect architectures.

In this trend, high-speed interconnect products such as optical transceivers, DAC, AOC, and AEC have become critical infrastructure that determines data center performance, power consumption, and scalability.

As a provider of high-speed interconnect solutions, C-LIGHT continues to expand its 400G, 800G, and 1.6T product portfolio, and delivers highly reliable interconnect solutions for AI data centers, GPU clusters, and cloud computing networks through a professional testing system.

1. Background of High-Speed Interconnect Evolution in Data Centers

The rapid expansion of AI training clusters is driving fundamental changes in data center networks:

• Continuous growth of GPU scale

• Wide adoption of Spine-Leaf architecture

• Rapid increase in port density

• Significant rise in east-west traffic

• Constantly increasing bandwidth demand

Traditional 100G networks can no longer meet the requirements of AI clusters.

Therefore:

• 400G is becoming mainstream

• 800G is entering large-scale deployment

• 1.6T is gradually moving toward commercialization

High-speed interconnect technologies are becoming increasingly critical.

2. Classification of Data Center High-Speed Interconnect Solutions

Modern data centers primarily use four types of high-speed interconnect technologies:

• Optical Transceivers

• DAC (Direct Attach Cable)

• AOC (Active Optical Cable)

• AEC (Active Electrical Cable)

Each solution serves different requirements in terms of distance, power consumption, and cost.

3. Optical Transceiver Technology Classification

Optical transceivers are the core high-speed optical interconnect components in data centers.

Their primary functions include:

• Electrical-to-optical signal conversion

• High-speed fiber transmission

• Interconnection between switches and servers

Form Factor Classification

QSFP28 (100G)

Widely used in 100G networks.

QSFP56 (200G)

Supports 50G PAM4 technology.

QSFP-DD (400G)

One of the mainstream 400G solutions.

Key features:

• High port density

• 8-lane architecture

• Suitable for Spine-Leaf networks

OSFP (800G)

Mainstream form factor for the 800G era.

Key features:

• Stronger thermal performance

• Higher power support

• Optimized for AI switches

OSFP-XD / 1.6T

Designed for next-generation 1.6T networks.

Supports:

• 16 lanes of 112G/224G PAM4

• Ultra-high bandwidth architecture

4. Optical Transceiver Technology Trends

4.1 Evolution from NRZ to PAM4

High-speed development drives modulation upgrades:

• 25G NRZ → 50G PAM4

• 100G PAM4 → 224G PAM4

PAM4 has become the foundational technology for 800G and 1.6T systems.

4.2 Lower Power Consumption

AI data centers are extremely sensitive to power efficiency.

Future optical transceivers focus on:

• Low-power DSP design

• Thermal optimization

• Silicon photonics integration

4.3 Higher Integration

Future trends include:

• Co-Packaged Optics (CPO)

• Silicon photonics technology

• Optoelectronic integrated architectures

These technologies further increase bandwidth density.

5. DAC (Direct Attach Cable) Technology Classification

DAC is a low-cost, low-power short-reach interconnect solution.

It is mainly used for:

• In-rack connections

• Top-of-Rack (ToR) switch interconnects

• GPU server connections

DAC Characteristics

Advantages:

• Low cost

• Ultra-low power consumption

• Ultra-low latency

Limitations:

• Limited transmission distance

• Higher signal loss at higher speeds

DAC Development Trends

With the adoption of 112G PAM4:

• 400G DAC is becoming mature

• 800G DAC is rapidly growing

• 1.6T DAC is under validation

Future directions include:

• Lower-loss materials

• Improved shielding performance

• Enhanced signal integrity (SI) design

6. AOC (Active Optical Cable) Technology Classification

AOC integrates optical transceivers and fiber into a single assembly.

Compared with DAC, it provides:

• Longer transmission distance

• Stronger interference resistance

• Better suitability for high-density cabling

AOC Applications

Widely used in:

• AI GPU clusters

• HPC networks

• Cloud data centers

• Cross-rack interconnects

AOC Development Trends

Future AOC solutions will evolve toward:

• Higher data rates

• Lower power consumption

• Lighter design

• Longer transmission distance

800G and 1.6T AOC will become key solutions in AI data centers.

7. AEC (Active Electrical Cable) Technology Classification

AEC is an active copper cable solution integrating:

• Retimers

• DSP chips

• Signal conditioning ICs

It addresses signal integrity challenges in high-speed copper transmission.

AEC Advantages

Compared with DAC:

• Longer transmission distance

• Better signal integrity

• More suitable for 112G high-speed systems

AEC Future Trends

Driven by AI switch upgrades, AEC will evolve toward:

• Lower latency

• Lower power consumption

• Higher stability

Demand for AEC is rapidly increasing in the 800G and 1.6T era.

8. C-LIGHT High-Speed Interconnect Product Portfolio

C-LIGHT has established a comprehensive interconnect product ecosystem covering:

Optical Transceivers

• 100G QSFP28

• 200G QSFP56

• 400G QSFP-DD

• 800G OSFP

• 1.6T next-generation roadmap

DAC Series

• 400G DAC

• 800G DAC

• AI GPU interconnect DAC

AOC Series

• 400G AOC

• 800G AOC

• High-speed AI cluster AOC

AEC Series

• 400G AEC

• 800G AEC

• High-density switch interconnect solutions

9. C-LIGHT Professional Testing System

The core competitiveness of high-speed interconnect products comes not only from design capability but also from rigorous testing.

C-LIGHT has established a comprehensive testing system including:

9.1 Signal Integrity (SI) Testing

• Eye diagram analysis

• Insertion loss

• Return loss

• Crosstalk

• Jitter

Ensures stable high-speed transmission.

9.2 Bit Error Rate (BER) Testing

Using professional BERT equipment:

• PRBS31 testing

• Long-duration stability validation

• Multi-channel synchronization testing

Ensures ultra-low error performance.

9.3 Optical Performance Testing

For optical modules and AOC:

• Optical power

• Receiver sensitivity

• OMA

• TDECQ

9.4 Environmental & Reliability Testing

Includes:

• Thermal cycling tests

• High-temperature aging

• Full-load operation

• Hot-plug testing

Enhances long-term reliability.

9.5 Compatibility Testing

Compatible with:

• NVIDIA

• Broadcom

• Intel

• AMD

• Major switch platforms

Ensures plug-and-play deployment.

10. AI Era Driving Continuous Evolution of High-Speed Interconnects

Future AI data centers will further accelerate:

• Large-scale 800G deployment

• Commercialization of 1.6T networks

• Adoption of 224G PAM4

• Development of CPO and silicon photonics

The high-speed interconnect market will continue to grow rapidly.

In the future:

• Optical transceivers

• DAC

• AOC

• AEC

will coexist and form optimal solutions for different application scenarios.

11. Conclusion

Driven by the rapid growth of AI computing power, high-speed interconnect has become one of the most critical infrastructures in modern data centers.

From 400G to 800G and toward 1.6T, optical transceivers and DAC/AOC/AEC technologies continue to drive the evolution of AI data center networks.

With a complete product portfolio and advanced testing system, C-LIGHT continues to deliver high-performance and high-reliability interconnect solutions to global customers, enabling the next generation of AI data center infrastructure.