Tuesday, July 21, 2009

The Next Step from Semiconductors: Light-Controlled Nano Switches

The nanotechnology world may be set up for a boost with the new discovery that light, such as infrared, creates a pushing or pulling force when split into two beams that each travel on a different length of silicon nanowire, called a wave guide (as illustrated in the above photo). Because the beams are not in phase, they create a repulsive force that is adjustable. The more out of phase the rays are, the greater the force.

The new technology might give you images of Iron Man with his repulsor beams and Luke Skywalker with his light saber, but the phenomenon behind it does not work in free space, according to Mo Li, a postdoctoral associate in electrical aengineering at Yale University. Li says it only works when light is confined in the nanoscale waveguides that are placed very close to each other on the chip.

The engineers see this new light-force technology could pave the way for nanodevices that are controlled by light instead of electrical switches, the latest of which are made possible with semiconductors. It is believed that light switches will make future gadgets and devices like computers lighter and cooler, both literally and figuratively.