ETH Zurich’s Pixel That Sees and Shows in One

Researchers at ETH Zurich built a pixel that both creates images and analyzes light. This is the first chip patch that can do both at once.

The pixel controls and studies brightness, phase, and polarization of light simultaneously. It uses interference of light waves combined with Fourier analysis to do this. The same tiny area shapes complex light beams and reads incoming light without a computer.

One of its tricks is producing exotic beams, including doughnut-shaped ones with a hole in the middle. It also works across different colors, not just a single wavelength. The pixel reacts to light in real time, generating a matching output immediately.

ETH Zurich’s team envisions scaling from a handful of these Fourier pixels to many. That would allow devices combining camera and display functions in one chip. Imagine screens that don’t just show images but also sense the scene in front of them.

The tech has already led to a patent application and is a candidate for ETH Zurich’s Spark Award. “Our new pixels for control and analysis could, therefore, become a useful tool in many areas,” said lead researcher Professor David Norris.

Postdoctoral researcher Sander Vonk explained, “We can also, however, apply the principle of interference and Fourier analysis in the opposite direction to analyze light using the Fourier pixel.” He added, “Thanks to the fact that the relevant surface profiles of the pixels can be determined using Fourier analysis, we can combine the control and analysis of amplitude, phase and polarization on a single pixel.”

The team demonstrated the pixel’s power by forming the letter ‘E’ with these Fourier pixels. The letter is about one millimeter tall, showing how tiny and precise the technology is.

This pixel breaks the old rule that a sensor either captures or displays light. Now, it can do both, opening a range of possibilities in optical computing and imaging. The future could hold screens that see as well as show.