Sadhvikas Addamane, Sandia National Laboratories, looks into a viewport of a molecular beam epitaxy reactor, a system Sandia will use to build experimental photonic cooling plates, designed at startup Maxwell Labs. [Image: Courtesy of Sandia National Laboratories / Craig Fritz]
Startup Maxwell Labs, based in Minnesota, USA, has entered into a cooperative R&D agreement with Sandia National Laboratories, USA, and the University of New Mexico, USA, to demonstrate laser-based photonic cooling for high-density computer processors. According to a company press release, the partnership aims to “revolutionize thermal management in data centers by leveraging cutting-edge photonic technology to enhance energy efficiency and unlock unprecedented processor performance.”
Turning down the heat
As AI workloads create a need for unprecedented computing power and put ever-higher demands on data centers, energy costs have become a growing concern—along with the tremendous heat generated by these activities. “About 30 to 40 percent of the energy data centers use is spent on cooling,” said Raktim Sarma, the lead Sandia physicist on the project.
Traditional heat-reduction methods include air, direct liquid and immersion cooling, but Maxwell Labs says that these approaches “fail to address the extreme heat generated in the dense, power-packed regions deep within processors.” To fill this perceived gap, the company has turned to laser cooling—a technique based on the change in momentum related to the absorption and re-emission of photons. The laser light is tuned such that a particular atom always re-emits the absorbed photon in a direction opposite to its motion, therefore slowing the atom down and corresponding to a lower temperature.
Maxwell’s method uses a photonic cold plate, designed with materials and microscopic features (about a thousand times smaller than the thickness of a human hair) that channel the laser to localized hot spots on chips, such as GPUs. “We really only have to cool down spots that are on the order of hundreds of microns,” Sarma said. The system would also allow the extracted heat, in the form of light, to be recycled back into electricity.
Maxwell CEO Jacob Balma said the company’s models indicate a laser-based cooling system can keep chips colder than water-based systems, explaining, “This will enable novel energy-recovery paradigms not possible with traditional cooling technology.”
Maxwell’s method uses a photonic cold plate, designed with materials and microscopic features that channel the laser to localized hot spots on chips, such as GPUs.
A team effort
Under the agreement, Maxwell Labs will provide the technical designs, Sandia Labs will fabricate highly pure gallium arsenide-based devices using its expertise in molecular beam epitaxy, and the University of New Mexico will evaluate the thermal performance of the resulting systems.
Sandia brings decades of experience in the production of high-quality semiconductors, noting in a press release that the purity of the gallium arsenide, which makes up most of the photonic cold plate, is essential for the system to succeed. “Because laser light will heat up impurities, erasing any cooling effect, the cold plate needs to have extremely pure, thin layers of crystalline gallium arsenide, also known as epitaxial layers, to work,” the lab explained.
“A successful project will not only address the immediate need for energy savings but also pave the way for processors to operate at performance levels that were previously thought impossible,” said Mike Karpe, cofounder and chief growth officer at Maxwell Labs. “This collaboration positions us to redefine the future of computing.”