"It is this fundamental science that allows us to shrink the device by orders of magnitude from the human scale to the nanoscale," said Cai.
Brongersma's area of expertise, plasmonics, then enters the scene. Plasmonics is the study of a curious physical phenomenon that occurs when light and metal interact. As photons strike metal they produce waves of energy coursing outward over the surface of the metal, like the ripples when a pebble is dropped in a pond.
Engineers have learned to control the direction of the ripples by patterning the surface of the metal in such a way that almost all of the energy waves are funneled inward toward the slit between the two metallic electrodes.
The light pours into the crevice as if over the edge of a waterfall and there it intensifies, producing light some 80 times stronger than the already intense laser levels from which it came. The researchers next apply a modest voltage to the metal resulting in the tremendous electrical field necessary to produce an EFISH beam.
"This type of device may one day find application in the communications industry," says Brongersma. "Most of the masses of information and social media interaction we send through our data centers, and the future data we will someday create, are saved and transmitted as electrical energy ones and zeros."
"Those ones and zeroes are just a switch; one is on, zero is off," said Cai. "As more energy-efficient optical information transport is rapidly gaining in importance, it is not a great leap to see why devices that can convert electrical to optical signals and back are of great value."
For the time being, however, the researchers caution that practical applications remain down the road, but they have created something new.
"It's a great piece of basic science," said Bron
|Contact: Andrew Myers|
Stanford School of Engineering