PASADENA, Calif.As technology advances, it tends to shrink. From cell phones to laptopspowered by increasingly faster and tinier processorseverything is getting thinner and sleeker. And now light beams are getting smaller, too.
Engineers at the California Institute of Technology (Caltech) have created a device that can focus light into a point just a few nanometers (billionths of a meter) acrossan achievement they say may lead to next-generation applications in computing, communications, and imaging.
Because light can carry greater amounts of data more efficiently than electrical signals traveling through copper wires, today's technology is increasingly based on optics. The world is already connected by thousands of miles of optical-fiber cables that deliver email, images, and the latest video gone viral to your laptop.
As we all produce and consume more data, computers and communication networks must be able to handle the deluge of information. Focusing light into tinier spaces can squeeze more data through optical fibers and increase bandwidth. Moreover, by being able to control light at such small scales, optical devices can also be made more compact, requiring less energy to power them.
But focusing light to such minute scales is inherently difficult. Once you reach sizes smaller than the wavelength of lighta few hundred nanometers in the case of visible lightyou reach what's called the diffraction limit, and it's physically impossible to focus the light any further.
But now the Caltech researchers, co-led by assistant professor of electrical engineering Hyuck Choo, have built a new kind of waveguidea tunnellike device that channels lightthat gets around this natural limit. The waveguide, which is described in a recent issue of the journal Nature Photonics, is made of amorphous silicon dioxidewhich is similar to common glassand is covered in a thin layer of gold. Just under two microns long, the devi
|Contact: Lawren Markle|
California Institute of Technology