ETH breakthrough: a pixel that is both a camera and a display
What was considered impossible for decades is now actually working: ETH Zurich has developed a pixel that displays images and analyses light at the same time. This could bring about fundamental changes to displays and cameras.
A pixel on your screen lights up. A pixel on your camera’s sensor measures light. Doing both at the same time – that wasn’t possible until now. Since the early days of display technology, this has been taken so much for granted that hardly anyone has ever questioned it. At least until now. Researchers at the Optical Materials Engineering Laboratory at ETH Zurich have now broken this fundamental principle for the first time.
Their so-called ‘ «’ Fourier pixel» can not only emit light – which is how an image is created on a display – but also detect and analyse it, thereby producing a photograph. The results were published this week in the specialist journal Nature, one of the world’s most prestigious scientific publications.
How does it work?
The trick lies in the physics of light waves. When light hits a surface, the reflected waves overlap – an effect known as «interference». Imagine two water waves meeting: where they reinforce each other, a wave crest forms. Where they cancel each other out, the water becomes smooth. It is precisely this principle that the ETH researchers are using to control light with nanometre precision.
The surface of the Fourier pixel works in a similar way: it is shaped in a wave-like pattern with nanometre precision. When light hits it, the reflected light waves interfere with one another, just like two water waves meeting: Where they reinforce each other, a wave crest is formed; where they cancel each other out, the surface remains smooth. These patterns – bright where waves reinforce each other, dark where they cancel each other out – form images. And because the same principle also works in reverse, the pixel can simultaneously analyse the type of light striking it.
The result: a tiny component that can replace two previously separate parts.
What does this mean in practical terms?
The most obvious application is a device that acts as both a display and a camera. For example, a smartphone without a visible camera lens, because the screen itself «sees». Or medical sensors that capture images and process them immediately, without the light first having to be laboriously directed through separate optical systems. According to study leader David Norris, the new pixels «are a useful tool in many fields» – from consumer electronics to fibre-optic communications.
Source: Glauser YM, Vonk SJW, et al., Nature 2026
Taking it one step further: the researchers have demonstrated that a Fourier pixel can measure and react simultaneously by analysing incident light and emitting a corresponding beam of light in real time. Without a computer in between. What does this mean? Sensors that not only capture data but respond immediately. And cameras that don’t have to send an image to a chip for processing before anything happens.
Not a product yet – but a genuine breakthrough
To put this into context: what has been developed in Zurich remains, for the time being, basic research. A commercial product is still a long way off. According to the research team, the next step is initially to extend the method to a matrix comprising several Fourier pixels – in other words, what a smartphone sensor with millions of pixels achieves today. It is likely to be some time before this is achieved and can be implemented on an industrial scale.
Nevertheless, the publication in Nature is no routine research result. The journal only accepts work that is considered truly novel. And the fact that a patent application has already been filed and the work has been nominated for this year’s ETH Spark Award suggests that the ETH itself also believes in its commercial potential.
The foundations have been laid.
I write about technology as if it were cinema, and about films as if they were real life. Between bits and blockbusters, I’m after stories that move people, not just generate clicks. And yes – sometimes I listen to film scores louder than I probably should.
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