Research
A pixel that both shapes and transmits light unlocks new capabilities for displays and sensors.
Researchers at ETH Zurich have created a multifunctional picture element—a pixel capable of both emitting and measuring light.
Conventional pixels typically serve only one purpose: either lighting a display screen or sensing light in a camera sensor.
Under the leadership of David Norris, professor at ETH Zurich’s Optical Materials Engineering Laboratory, the team has succeeded in merging these two functions.
This breakthrough opens the door to bidirectional screens that can capture and display images, holographic displays, optical communication links, and quantum‑information processors.
As detailed in the Nature paper “Fourier pixels for bidirectional light control,” the ETH Zurich researchers devised a method that analyses light‑wave interference patterns on a metal surface.
By exploiting this interference, they generate “Fourier pixels” that can both produce and sense the amplitude, phase, and polarization of optical fields.
The Fourier transform converts a time‑domain signal—such as a sound wave—into its constituent frequencies. In this context, a Fourier pixel encodes the spatial frequency of light rather than the simple brightness at a single image point.
“Because the surface profile of each pixel can be derived through Fourier analysis, we can simultaneously control and analyse amplitude, phase, and polarization on one element,” explained post‑doctoral researcher Sander Vonk in an ETH Zurich press release.
In the short term, Norris plans to arrange Fourier pixels into an array for use in advanced camera‑display systems.
Additional contributors to the study are Yannik M. Glauser, David B. Seda, Hannah Niese, Boris de Jong, Matthieu F. Bidaut, Daniel Petter, Erwan Bossavit, Gabriel Nagamine, and Nolan Lassaline.
