Needle beam stays on point
A Harvard-led team of researchers has demonstrated a new type of light beam that propagates without spreading outward, remaining very narrow and controlled along an unprecedented distance. This “needle beam,” as the team calls it, could greatly reduce signal loss for on-chip optical systems and may eventually assist the development of a more powerful class of microprocessors. Based at the Harvard School of Engineering and Applied Sciences (SEAS) and the Laboratoire Interdisciplinaire Carnot de Bourgogne, at the National Center for Scientific Research (CNRS), in France, the applied physicists both characterized and created the needle beam. Their findings were published online Aug. 31 in the journal Physical Review Letters. The needle beam arises from a special class of quasiparticles called 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...