Light Manipulation Reaches a New Dimension: Scientists Achieve Real-Time Control of Photons
Through ultrafast material changes, researchers can now precisely influence the direction and energy of light particles for the first time.

Optics Breakthrough: Real-Time Manipulation of Light

For decades, scientists have been searching for ways to overcome the limits of traditional electronics. Using light for information processing promises significant advantages: photons move faster than electrons and generate less heat. However, previous attempts to control light with sufficient precision often failed due to material limitations or overly complex setups. Real-time control of individual photons has long been considered the “Holy Grail” of optical technologies. Now, a material has been discovered that reacts fast enough to make this vision a reality.

The team led by Dr. Marcello Ferrera, Associate Professor of Nanophotonics at Heriot-Watt University in Edinburgh, Scotland, used transparent conducting oxides (TCOs) to create ultrathin films only 250 nanometers thick. These nanomaterials—already known from solar cells and touchscreens—respond rapidly to light. By exposing the TCOs to femtosecond laser pulses, the researchers can dynamically change the material’s optical properties in real time.

The Key: Temporal Manipulation

Unlike traditional optical elements with fixed properties, these TCOs can be dynamically “reprogrammed.” Dr. Ferrera explains:
“The material characteristics we studied could increase processing speeds by several orders of magnitude while using only a fraction of the energy currently required to process large volumes of information.”

This leap in efficiency stems from using light directly for processing data, eliminating the need to convert optical signals into electrical ones. The real-time tuning of material properties enables several innovations:

• Parallel Processing of Multiple Light Frequencies:
  Traditional optical components often work at a fixed wavelength. Dynamic TCOs, by contrast, can utilize different colors (frequencies) of light simultaneously.

• Reduced Energy Loss:
  Electronic systems consume energy converting optical signals to electrical ones (e.g., in fiber optics). Purely optical control eliminates this loss. TCOs require minimal energy as they’re activated by short light pulses.

“It’s hard to grasp the impact this breakthrough will have on our daily lives,”
says Dr. Marcello Ferrera.

Published in Nature Photonics

In their article in Nature Photonics, the scientists explain how the TCOs work: light pulses change the electronic structure so rapidly that the material’s interaction with passing light can shift while the light is still traveling through. This enables simultaneous control of both the direction and energy of individual photons—something never before achieved in photonics, according to the researchers.

The technology holds promise across various sectors. Data centers and AI systems, for example, could see dramatic boosts in performance alongside reduced energy usage. Experts believe this could lay the foundation for a new generation of purely optical components that no longer rely on slow electrical signals.