ETH Team Develops a New Type of Pixel

(CONNECT) A research team led by David Norris, a professor at the Optical Materials Engineering Laboratory at ETH, has developed pixels that, for the first time, can do two things: they can both control and analyse light. According to a report by ETH, this applies not only to the intensity of the light, but also to its phase and polarisation. As a result, these so-called bidirectional pixels could, for example, be used in the future to create camera displays that combine both functions in a single device.

The new findings have now been published in the scientific journal *Nature*. They are based on what is known as the interference of light waves. Norris and his team use this effect to precisely control light using a material with a wave-like surface. They developed this method, which is accurate to the nanometer, several years ago. The interference of light waves can then create patterns and images.

Researchers can use the mathematically simple Fourier analysis to determine what these images look like and what surface pattern is needed for a specific image. The oscillation phase can also be precisely controlled. According to the report, this even makes it possible to produce donut-shaped beams of light with a hole in the center.

Light is used in many technologies, from television to cell phone cameras to fiber-optic internet. “Our new control and analysis pixels could therefore become a useful tool in many fields,” says Norris. It is even conceivable that these pixels could respond to a captured image without going through a computer and emit corresponding light patterns.

Norris cites the extension of the method to a matrix consisting of multiple Fourier pixels as a short-term goal. This could then make it possible to develop complex camera-display devices that operate like conventional cameras or displays with a large number of pixels. A patent application has been filed for this research, which is scheduled for this year’s has been nominated for a Spark Award. ce/mm