1.6T Co-Packaged Optical modules are tested for compliance and performance using stressed optical signals, high-speed BERTs, and silicon photonics-based integration to ensure reliable 1.6 Tb/s operation.

Overview of 1.6T Co-Packaged Optics (CPO)

1.6T CPO integrates optical engines directly with switch ASICs, reducing electrical trace lengths from inches to millimeters, which dramatically lowers power consumption from ~30W in pluggable modules to ~9W per module . This architecture supports high-density AI and hyperscale data center deployments by minimizing DSP overhead and improving energy efficiency . The modules operate at 224 Gb/s per lane, leveraging silicon photonics and advanced packaging techniques to achieve high bandwidth and low latency .

Testing Methodology

Testing 1.6T optical modules involves receiver conformance validation to IEEE 802.3dj standards . Key steps include:

• Stressed Optical Signal Generation: Emulating worst-case transmitter behavior with precise metrics such as Outer Extinction Ratio (OER), Optical Modulation Amplitude (OMA), and Stress Eye Closure Quaternary (SECQ).
• Instrumentation: Using a combination of 120 GBaud BERTs, tunable lasers, interference sources, optical reference transmitters, attenuators, and optical sampling scopes controlled by automated test software.
• Calibration: Iterative optimization ensures stress signals remain stable and repeatable, accounting for inter-symbol interference, sinusoidal jitter, and Gaussian noise.
• Multi-Lane Validation: Ensures repeatability across multiple lanes and test cycles, critical for silicon bring-up and transceiver validation.
• Interface Flexibility: Supports DR1, FR4, and LR4 interfaces at symbol rates up to 113.4375 GBd .

Performance Evaluation

Performance testing focuses on:

• Signal Integrity: Measuring bit error rates (BER) and forward error correction (FEC) performance under stressed conditions.
• Power Efficiency: Comparing CPO modules to conventional pluggable modules, highlighting reduced DSP power requirements and lower thermal load .
• Bandwidth and Latency: Ensuring 1.6 Tb/s throughput with minimal signal degradation over short electrical paths.
• Compliance: Verifying adherence to IEEE 802.3dj and other relevant standards for high-speed Ethernet and data center interconnects .

Test Report Components

A comprehensive 1.6T CPO test report typically includes:

1. Module Identification: Part numbers, lane configuration, and optical engine specifications.
2. Test Setup Description: Instrumentation, calibration procedures, and environmental conditions.
3. Stressed Signal Metrics: OER, OMA, SECQ, jitter, and noise parameters.
4. Receiver Performance: BER, FEC margin, and eye diagram analysis.
5. Power and Thermal Data: Module power consumption, DSP load, and thermal performance.
6. Compliance Statement: Confirmation of IEEE 802.3dj conformance and multi-lane repeatability.

Conclusion

1.6T Co-Packaged Optical modules are validated through rigorous, automated testing that combines stressed optical signal generation, high-speed BERTs, and silicon photonics integration. These tests ensure high-speed, low-power, and standard-compliant operation, enabling deployment in AI-scale and hyperscale data center networks while reducing energy consumption and improving system density .