Engineers at the Technical University of Denmark have built a nanolaser that could change how chips move information, replacing electrical signals with light.
The device is built around a nanocavity that traps light in an exceptionally small space, a design the team calls extreme dielectric confinement. Because the light is squeezed so tightly, the laser works at room temperature and needs very little power. The results were published in the journal Science Advances.
Light instead of electrons
Modern processors push data across copper traces as electrical current, which wastes energy as heat and slows down as signals travel. Optical links already connect servers inside data centres, but shrinking them onto a chip has been hard because lasers usually need to be far larger than the transistors around them.
The DTU design breaks that size limit. Thousands of the lasers could sit on one microchip, each sending photons through a waveguide rather than electrons through a wire. 'The nanolaser opens up the possibility of creating a new generation of components that combine high performance with minimal size,' said Professor Jesper Mork, who led the work.
Where the savings come from
Mork estimates that using nanolasers in computers could cut energy consumption by as much as half. The gain would not come from one improvement but from several at once: less resistive heating inside circuits, less cooling needed in data centres, and faster transfer speeds that let chips finish work sooner. Data centres already consume a large and growing share of global electricity, so small efficiency gains scale into large savings.
The team built the device in the university's DTU Nanolab clean room. The remaining problem is power. The current laser is driven optically, and making it work with an electrical current is the next research challenge. Mork said that step could take five to ten years, and that it would open the door to optical computing on a chip.
Beyond computing, the researchers see uses in health technology, where concentrated light enables high-resolution imaging and very sensitive biosensors.