New Nanolaser Could Cut Computer Energy Use by Half

Engineers at the Technical University of Denmark (DTU) have built a laser small enough for thousands to fit on a single computer chip, a step toward chips that move data using light instead of electricity. The nanolaser, developed by DTU professor Jesper Mork with researchers Meng Xiong and Yi Yu, is described in the journal Science Advances.

Inside computers today, data travels through electronic circuits, which produces heat and limits how fast information can move. Nanolasers could let chips send data as photons, the particles that make up light, instead of electrical signals, cutting energy loss. Mork estimates that using nanolasers this way could reduce a computer's energy consumption by as much as half.

At the heart of the device is a nanocavity, a structure that traps and concentrates light within an extremely small space, something researchers had long considered very difficult to achieve at this scale. When a beam of light is shone on the device, photons and electrons become concentrated in the same microscopic region, letting the laser operate at room temperature while using unusually little energy. The nanolaser was built in DTU's clean-room facility, DTU Nanolab, using a light-trapping structure originally developed by professor Ole Sigmund's group at DTU Construct.

Mork said the nanolaser's extreme light concentration could also be applied to healthcare sensors and high-resolution imaging. Data centers, which consume enormous amounts of power, could also see substantial energy savings if the technology reaches that scale. The next major challenge is making the device operate using electrical power rather than an external light source. The researchers estimate that the remaining technical challenges could be solved within the next five to ten years.