Photonic Integration for Datacenters
Datacenters are a critical component of the modern internet, responsible for processing and storing tremendous amounts of data in the “cloud.” Datacenters also provide the computational power needed for handling “big data,” a growing segment of the U.S. economy. Currently, datacenters consume more than 2.5% of U.S. electricity and this figure is projected to double in about eight years due to the expected growth in data traffic. There are many approaches to improving the energy efficiency of datacenters, but these strategies will be limited by the efficiency with which information travels along metal interconnects within the devices in the datacenter—all the way down to the computer chips that process information. Unlike metal interconnects, photonic interconnects do not rely on electrons flowing through metal to transmit information. Instead, these devices send and receive information in the form of photons—light—enabling far greater speed and bandwidth at much lower energy and cost per bit of data. The integration of photonic interconnects will enable new network architectures and photonic network topologies that hold the potential to double overall datacenter efficiency over the next decade.
Project Innovation + Advantages:
The University of California, Santa Barbara (UCSB) will develop and demonstrate a technology platform that integrates efficient photonic interfaces directly into chip "packages." The simultaneous design and packaging of photonics with electronics will enable higher bandwidth network switches that are much more energy efficient. Traditional electronic switches toggle connections between wires, each wire providing a different communication channel. Having a limited number of communication channels means that electronic switches can lead to “fat” hierarchical networks, consuming energy each time data has to travel through one switch to another. By developing a platform that directly integrates efficient photonics into first-level chip packages, layers of traditional network hierarchy can be eliminated, reducing the power, latency, and cost of datacenters. Photonic interconnects integrated directly into chip packages can enable switches with a much larger port count than traditional electronic switches. These new, larger switches will connect more servers using fewer levels of required switching. The team estimates that an improvement in the network metrics (either cost or power) will enable a more than linear improvement in the overall transactional efficiency because faster networks and faster endpoint data-rates can be deployed, reducing the total number of computational and storage systems necessary to satisfy user transactions.
If successful, developments from ENLITENED projects will result in an overall doubling in datacenter energy efficiency in the next decade through deployment of new photonic network topologies.
The United States is home to much of the world’s datacenter infrastructure. Photonic networks add resilience that can bolster the energy security of this critical driver of economic activity.
Reducing the overall energy consumption of datacenters cuts energy-related emissions per bit of data processed or stored.
Photonic networks can lower the costs associated with operating datacenters, improving American economic competitiveness in this fast-developing area.