Tiny nanolaser could cut computer energy use in half

Researchers at DTU have created a tiny nanolaser that could eventually help make computers, smartphones, and data centers faster while using much less energy. The breakthrough was published in the scientific journalScience Advances.

In the future, thousands of these lasers could potentially be integrated onto a single microchip. Instead of moving information around a chip with electrical signals, devices could transmit data using photons, the particles that make up light.

"The nanolaser opens up the possibility of creating a new generation of components that combine high performance with minimal size. This could be in information technology, for example, where ultra-small and energy-efficient lasers can reduce energy consumption in computers, or in the development of sensors for the healthcare sector, where the nanolaser's extreme light concentration can deliver high-resolution images and ultrasensitive biosensors," says DTU professor Jesper Mørk.

Mørk co-authored the study with, among others, Drs. Meng Xiong and Yi Yu from DTU Electro.

Using Light Inside Computer Chips

Much of the internet already relies on light to carry information through fiber optic cables. Inside computers, however, data still moves through electronic circuits using electricity. That approach produces heat and can limit how quickly information can be transferred.

Nanolasers could bring optical communication directly onto microchips. By generating light signals efficiently inside the chip, they could allow information to move with very little energy loss, potentially making future devices faster, cooler, and more energy efficient.

Mørk estimates that using nanolasers in computers could reduce energy consumption by as much as half.

The compact DTU nanolaser is an important step toward that goal. Future chips designed around light-based communication would likely require thousands of extremely small, efficient lasers working together to transmit information across the chip.

Breaking the Size Limit for Lasers

The new nanolaser was created in DTU's clean room facility, DTU Nanolab. According to Mørk, the device pushes beyond the conventional limit for how small a laser can be made.

At its core is a structure known as a nanocavity, which traps and concentrates light within an exceptionally tiny space. Until now, achieving such intense confinement at this scale had been considered extremely difficult.

When researchers shine a beam of light onto the device, both photons and electrons become concentrated in the same microscopic region. This interaction allows the laser to function at room temperature while requiring unusually little energy.

The light-trapping structure used in the nanolaser was originally developed by Professor Ole Sigmund's group at DTU Construct.

Faster Devices and Lower Energy Use

The next major challenge is making the nanolaser operate using electrical power. If researchers can achieve that, the technology could have broad applications across computing, communications, and healthcare.

Computers and smartphones could potentially deliver greater performance while consuming less electricity. Data centers, which require enormous amounts of power, could also see substantial reductions in energy use, potentially leading to significant climate benefits.

In healthcare technology, the nanolaser's ability to concentrate light into an extremely small area could support ultra-sensitive sensors and high-resolution imaging systems.

Researchers estimate that the remaining technical challenges could be solved within the next 5-10 years.