Researchers at the Swiss Federal Institute of Technology (ETH) have discovered what the computer industry has been looking for since 20 years: A method of combining light and electronics on an ultrafast chip. Their plasmonic chip is more powerful, smaller, and cheaper to produce than any previous technology.
The chip will soon become an absolute necessity. After all, the maximum of 100 gigabits per line and wavelength available in optical fiber networks today will not be sufficient to meet the growing demand: for online streaming, storage, and processing power, as well as the emergence of artificial intelligence and 5G networks.
“In order to keep up with the growing demand, we need new approaches,” says Jürg Leuthold, ETH Professor of Photonics and Communications. “The key to this paradigm shift lies in bringing together electronic and photonic components on a single chip.”
Photonics (“the science of light particles”) is the research of optical technologies for the transmission, storage, and processing of information. ETH researchers have now achieved precisely this combination.
Until now, the crux has been that photonic chips are much larger than electronic ones. This made it difficult to combine the technologies on a single chip, Jürg Leuthold says. The size of the photonic components makes it impossible to combine them with the metal-oxide-semiconductor technology (CMOS) that is commonly used in electronics today.
The ETH team solved this by replacing photonics with plasmonics. Plasmonics can be used to force light waves into structures that are much smaller than the wavelength of the light. Now, this can also be achieved using what are known as “monolithic” chips.
This offers several advantages: On the one hand, producing the electronic and photonic chips separately is cost-intensive. On the other, it reduces the power required to convert the electronic signals into light signals and thus limits the transmission speed in light-guiding communication networks, explains Ueli Koch, post-doctoral researcher in Jürg Leuthold’s group and lead author of the study published in the “Nature Electronics” journal.
In experiments, the plasmonic chip has already proven its potential. It was possible to demonstrate that these technologies could be combined to create one of the fastest compact chips: “We are convinced that this solution can enable faster data transmission in optical communication networks in the future.”
Written by sda
Photos by ETH Zürich / Nature Electronics