Today’s computers reach their physical limits when it comes to speed. Semiconductor components usually operate at a maximum usable frequency of a few gigahertz – which corresponds to several billion computing operations per second. As a result, modern systems rely on several chips to divide up the computing tasks because the speed of the individual chips cannot be increased any further. However, if light (photons) were used instead of electricity (electrons) in computer chips, they could be up to 1,000 times faster.
Plasmonic resonators, also known as “antennas for light”, are a promising way of achieving this leap in speed. These are nanometre-sized metal structures in which light and electrons interact. Depending on their geometry, they can interact with different light frequencies.
“The challenge is that plasmonic resonators cannot yet be effectively modulated, as is the case with transistors in conventional electronics. This hinders the development of fast light-based switches,” says Dr. Thorsten Feichtner, physicist at Julius-Maximilians-Universität (JMU) Würzburg in Bavaria, Germany.