Researchers at ETH Zurich (Zurich, Switzerland) have developed a pixel that can create and analyze images simultaneously.
Pixels, the basic building blocks of imaging, have traditionally been able to either control light to display an image, such as in a television screen or computer monitor, or analyze light to form an image, such as in a camera sensor.
The team, led by David Norris, a professor at ETH Zurich’s Optical Materials Engineering Laboratory, published their peer reviewed findings in the scientific journal “Nature” and recently announced the development in an ETH Zurich press release.
While the research is still in the early stages, the team has introduced capabilities that were not previously possible, Norris said.
“We can generate and sense light with full control over the light’s intensity, phase, and polarization,” Norris said. "In particular, we have made individual pixels. One of the next steps is to try to make arrays of such pixels.”
The team’s results are based on a fundamental physical effect known as the interference of light waves, which refers to how light waves originating from different points on a surface overlap when that surface scatters light. The shape of that surface determines oscillation phases. If those phases are equal, the light waves reinforce each other. If they are opposed, the waves cancel out.
According to the press release, Norris and his team used this effect to precisely control light with wave-shaped sculpted surfaces. For steering, the pixel—that is, the area on the chip where the material has been processed—first transforms the incoming light into a surface wave propagating along the surface of the chip. At a different point within the pixel, the surface wave is scattered back out of the material as a light wave. Through interference of the light waves, patterns and images can be created. Using mathematical Fourier analysis, the researchers can calculate what these images will look like and what kind of surface pattern is needed for a specific image.
“This pixel can help detect and generate light with much higher information content,” Norris said. “It can potentially image using intensity contrast, phase contrast, and polarization contrast.”
The team’s research is still in early stages, which means they have not yet determined for what applications the technology might ultimately be useful. However, Norris said he believes it could benefit a number of imaging applications.
“If collecting or generating light with much higher information content is important, there is no other way to do it,” Norris said.
Related: Novel Sensor Material Demonstrates Better Color Image reproduction Than Silicon
