As AI workloads push data movement to its limits, photonics is often proposed as a way to move data faster with less energy. But a panel of EDA and semiconductor experts at the Design Automation Conference cautioned that photonics brings its own thermal complexity. Co-packaged optics, which place silicon photonics inside the package, require careful thermal isolation, yet the transient behavior of heat moving across multi-die assemblies is still poorly understood.
The experts converged on a central problem: today's tools cannot accurately simulate the time-dependent thermal and mechanical behavior of these systems. Heat from an ASIC can linger and shift ring oscillators, while thousands of integrated heaters needed to stabilize photonic structures create their own hot spots. Mechanical stress from mounting electronic and photonic dies together can distort optical signals, sometimes more than temperature itself.
There was broad agreement that transient simulation of the entire package—not just individual components—is essential to making co-packaged optics viable. However, the panel also noted that tools for predicting thermally accelerated aging are still lacking. Until these modeling gaps are closed, photonics will remain promising but difficult to scale in real AI systems. The discussion was the second in a three-part series, with further details expected on system reliability and aging. (The source is a single roundtable; no direct disagreements among panelists were reported.)