Nvidia has developed a prototype that places optical engines directly on the interposer alongside computing chips, bringing electrical-to-optical conversion closer to the processor. Presented at Semicon West, the optics-on-interposer technology aims to increase bandwidth density and reduce power consumption. It remains a research project, with no commercialization timeline announced.² Credit: Nvidia An interposer provides fine wiring between chips, while the organic substrate beneath it distributes power and connects the package to a circuit board. Existing co-packaged optics designs route electrical signals through both layers to reach the optical engines. Nvidia’s approach removes the organic substrate from this signal path, using shorter, denser interposer connections similar to those linking GPUs and high-bandwidth memory. The advantage is more connections within a small area and less energy spent driving electrical signals. The research builds on Nvidia’s existing co-packaged optics products, which place optical engines around a central switch chip on the package substrate. Moving them onto the interposer introduces further integration challenges, including testing, fiber alignment and cooling. Nvidia says a manufacturing ecosystem spanning chip production, packaging, lasers and optical connections is essential to make the technology suitable for volume production.