Light beam could lead to more powerful microprocessors

Dubbed ‘needle beam’ by the Harvard-led team, the development could reduce signal loss for on-chip optical systems and may eventually assist the development of a new class of powerful microprocessors.

Based at the Harvard School of Engineering and Applied Sciences (SEAS) and the Laboratoire Interdisciplinaire Carnot de Bourgogne (CNRS) in France, the applied physicists characterised and created this needle beam, which travels at the interface of gold and air.

Their findings were published online on 31 August in the journal Physical Review Letters.

According to a statement, the needle beam arises from surface plasmons, which travel in tight confinement with a metal surface. The metallic stripes that carry these surface plasmons have the potential to replace standard copper electrical interconnects in microprocessors, enabling ultrafast on-chip communications.

One of the fundamental problems that has so far hindered the development of such optical interconnects is the fact that all waves naturally spread laterally during propagation, a phenomenon known as diffraction. This reduces the portion of the signal that can be detected.