Researchers at ETH Zurich have built a new kind of optical pixel that can do a useful job: emit light like a display pixel and read light like a camera sensor. The device, called a Fourier pixel, is designed for systems where a screen and a camera no longer have to live on separate hardware, from AR/VR glasses to adaptive optics and material analysis tools.
That matters because most pixels today are specialists. Camera pixels detect light; display pixels produce it. The ETH Zurich design tries to collapse both roles into one nanostructured element, which is the sort of trick engineers reach for when they want smaller devices, fewer components, and less optical compromise.
How the Fourier pixel works
The core idea is refreshingly mathematical. The pixel uses surface plasmon polaritons, which are coherent waves moving along a metal surface, and shapes that surface with a profile calculated using Fourier transforms. Incoming light excites the surface wave, the structure reshapes it, and the outgoing light emerges with a controlled amplitude, phase, and polarization.
In plain English: the surface acts like a tiny optical processor. Instead of just measuring brightness, it can handle more of the wave’s properties, and instead of just shining light, it can emit a prescribed optical pattern. The researchers say the nanostructure can be fabricated with nanometer precision, which removes one excuse for industry to keep calling this ”future tech.”
What the Fourier pixel can do
Because the device can manipulate multiple light parameters at once, the use cases are broader than a smarter screen. The same pixel architecture could support color displays that also analyze reflected light, 3D image generation, microscope and telescope focusing, atmospheric turbulence correction, telecom systems, and even optical or quantum computing.
- Display light and sense light in the same pixel
- Control amplitude, phase, polarization, and wavelength
- Support compact AR/VR hardware without a separate camera
- Enable optical effects such as a beam shaped like a ring
Why this is more than a clever demo
The deeper story is not the fancy naming or the wave physics; it is the long-running push to make optics more programmable. Competing approaches in displays and sensors usually trade flexibility for efficiency, and that trade-off has shaped everything from smartphone cameras to headsets. A pixel that can both sense and emit pushes back against that split, which is why researchers keep circling this same idea in different forms.
Whether it turns up first in research instruments, specialty displays, or communications gear is the real question. Consumer devices love the promise of fewer parts, but they also punish anything that is expensive, delicate, or hard to manufacture at scale. If this technology escapes the lab, the first winners will probably be the systems that already care more about optical precision than cheap volume.