Light instead of copper: micro-LEDs hit record 2.75 GHz bandwidth
An Illinois team reports a record modulation bandwidth for blue gallium nitride micro-LEDs, which could replace power-hungry copper links in data centers.
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Researchers at the University of Illinois Urbana-Champaign report a record modulation bandwidth of 2.75 gigahertz for a blue gallium nitride micro-LED just 5 micrometers across. The results were published Oct. 21 in IEEE Electron Device Letters. Professor Can Bayram's team studied devices ranging from 100 to 2 micrometers.
Smaller diodes have lower capacitance, allowing faster switching, but below 5 micrometers contact resistance rises. The goal is dense, low-energy optical channels to replace copper links, which the report says consume a lot of power, generate heat and can no longer keep up with data center data rates.
The technology is also reaching industry: California-based Palomino Laboratories said on Oct. 26 it had received its first purchase order from an unnamed "strategic hyperscaler customer", for GaN micro-LED chips for optical interconnects.