External light sources emerge as key to scaling CPO
New architectures that separate lasers from high-heat processors are gaining traction as AI datacentres push the limits of co-packaged optics.
External light sources (ELS) are emerging as a critical enabler for scaling co-packaged optics (CPO) in next-generation AI datacentres, as the industry looks to overcome mounting thermal, reliability and integration challenges.
As AI workloads continue to expand, traditional electrical interconnects are increasingly unable to meet the bandwidth and energy efficiency demands of modern data centre architectures.
CPO has been widely identified as a solution, integrating optical components directly with GPUs and switch packages to deliver high-speed, low-power connectivity. However, the approach introduces new challenges, particularly around thermal management and laser stability.
ELS architectures address this issue by relocating temperature-sensitive lasers away from high-power processing units. This separation improves wavelength stability, enhances system reliability and simplifies serviceability, making ELS an increasingly attractive approach for both scale-out and scale-up optical systems.
Recent industry activity highlights growing momentum behind this shift. Sivers Semiconductors, O-Net Technologies and Enablence Technologies have announced a collaboration to develop an advanced ELS module designed to support CPO deployment in AI and high-performance computing environments.
The solution combines laser arrays with photonic distribution technologies to enable scalable, high-density optical interconnects.
The move reflects a broader industry trend, as data centre operators and technology providers seek practical pathways to scale optical connectivity without compromising performance or efficiency.
With market forecasts pointing to rapid growth in CPO adoption over the coming decade, ELS solutions are expected to play a central role in enabling reliable and manufacturable architectures.
As AI infrastructure continues to evolve, the shift towards ELS-based designs signals a growing recognition that optical innovation at the system level will be essential to sustaining performance gains in increasingly complex computing environments.
