Data centers are one of the key elements that enable meeting the demand of the continuous increase in global internet traffic produced by a nearly exponential growth in the use of cloud-based applications, streaming services, social media and big data analytics, among others. However, most of this traffic is not between data centers and users or between data centers, but it is produced within the data centers themselves (above 70% of the total data center traffic is internal traffic). A key implication of this situation is the increase in the energy consumption of these infrastructures, which is significantly influenced by the demanding cooling requirements to mitigate the heating derived from the use of high-speed electrical signals. In fact, data centers currently account for around 1% of global electricity demand, but it is expected that this demand might reach values even around 8% by 2030. So, adequate technological solutions must be developed to address this significant problem, which implies a great environmental impact.
The ULAPOP project addresses this problem by proposing the development of an innovative and energy-efficient switching solution for routing of high-speed traffic within the data center, something that is currently done at the electrical level. This will be achieved by using silicon photonics technology, which has already demonstrated its potential in this context by means of the development of high-speed transceivers, but where novel devices that replace functionalities currently performed in the electrical domain are required to improve the performance and reduce the power consumption. More concretely, we propose developing a disruptive photonic switching technology based on a chalcogenide material (antimony selenide or Sb2Se3), which can provide a non-volatile and large refractive index change with almost negligible losses. In this way, optical phase switching can be achieved at ultra-short lengths and requiring a low power consumption as the switching state remains after reconfiguring the device without requiring further energy. Thereby, power consumption is expected to improve by several orders of magnitude with respect to current state-of-the-art silicon switching devices.