New nanotech applications may be made possible by the demonstration of a force generated from light that differs from the more familiar radiation pressure, and that is more versatile because it does not require a reflective surface. This force can be used to make light drive nanoscale machinery on a silicon chip. From Yale University, via AAAS EurekAlert “Harnessing light to drive nanomachines“
…a team led by researchers at the Yale School of Engineering & Applied Science has shown that the force of light indeed can be harnessed to drive machines — when the process is scaled to nano-proportions.
Their work opens the door to a new class of semiconductor devices that are operated by the force of light. They envision a future where this process powers quantum information processing and sensing devices, as well as telecommunications that run at ultra-high speed and consume little power.
The research, appearing in the November 27 issue of Nature [abstract], demonstrates a marriage of two emerging fields of research — nanophotonics and nanomechanics — which makes possible the extreme miniaturization of optics and mechanics on a silicon chip.…
“While the force of light is far too weak for us to feel in everyday life, we have found that it can be harnessed and used at the nanoscale,” said team leader Hong Tang, assistant professor at Yale. “Our work demonstrates the advantage of using nano-objects as “targets” for the force of light — using devices that … match the size of today’s typical transistors.”
Until now light has only been used to maneuver single tiny objects with a focused laser beam — a technique called “optical tweezers.” Postdoctoral scientist and lead author, Mo Li noted, “Instead of moving particles with light, now we integrate everything on a chip and move a semiconductor device.”
“When researchers talk about optical forces, they are generally referring to the radiation pressure light applies in the direction of the flow of light,” said Tang. “The new force we have investigated actually kicks out to the side of that light flow.”
While this new optical force was predicted by several theories, the proof required state-of-the-art nanophotonics to confine light with ultra-high intensity within nanoscale photonic wires. The researchers showed that when the concentrated light was guided through a nanoscale mechanical device, significant light force could be generated — enough, in fact, to operate nanoscale machinery on a silicon chip.
—Jim
