Featured Research

from universities, journals, and other organizations

Silicon Photonic Crystals Key To Optical Cloaking, Researchers Say

Date:
June 26, 2008
Source:
University of Illinois at Urbana-Champaign
Summary:
In computer simulations, researchers at the University of Illinois have demonstrated an approximate cloaking effect created by concentric rings of silicon photonic crystals. The mathematical proof brings scientists a step closer to a practical solution for optical cloaking.

Now you see it, soon you might not, researchers at the University of Illinois say.

Related Articles


In computer simulations, the researchers have demonstrated an approximate cloaking effect created by concentric rings of silicon photonic crystals. The mathematical proof brings scientists a step closer to a practical solution for optical cloaking.

"This is much more than a theoretical exercise," said Harley Johnson, a Cannon Faculty Scholar and professor of mechanical science and engineering at Illinois. "An optical cloaking device is almost within reach."

In October 2006, an invisibility cloak operating in the microwave region of the electromagnetic spectrum was reported by researchers at Duke University, Imperial College in London, and Sensor Metrix in San Diego. In their experimental demonstration, microwave cloaking was achieved through a thin coating containing an array of tiny metallic structures called ring resonators.

To perform the same feat at much smaller wavelengths in the visible portion of the spectrum, however, would require ring resonators smaller than can be made with current technology, Johnson said. In addition, because metallic particles would absorb some of the incident light, the cloaking effect would be incomplete. Faintly outlined in the shape of the container, some of the background objects would appear dimmer than the rest.

To avoid these problems, postdoctoral research associate Dong Xiao came up with the idea of using a coating of concentric rings of silicon photonic crystals. The width and spacing of the rings can be tailored for specific wavelengths of light.

"When light of the correct wavelength strikes the coating, the light bends around the container and continues on its way, like water flowing around a rock," Xiao said. "An observer sees what is behind the container, as though it isn't there. Both the container and its contents are invisible."

Currently simulated in two dimensions, the cloaking concept could be extended to three dimensions, Xiao said, by replacing the concentric rings with spherical shells of silicon, separated by air or some other dielectric.

The researchers' optical cloaking technique is not perfect, however. "The wave fronts are slightly perturbed as they pass around the container," said Johnson, who also is affiliated with the university's Beckman Institute and the Frederick Seitz Materials Research Laboratory. "Because the wave fronts don't match exactly, we refer to the technique as 'approximate' cloaking."

Xiao and Johnson's work is highlighted in the June issue of the Materials Research Society Bulletin. The researchers describe their work in a paper published in the April 15 issue of the journal Optics Letters.

Funding was provided by the U.S. Department of Energy.


Story Source:

The above story is based on materials provided by University of Illinois at Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University of Illinois at Urbana-Champaign. "Silicon Photonic Crystals Key To Optical Cloaking, Researchers Say." ScienceDaily. ScienceDaily, 26 June 2008. <www.sciencedaily.com/releases/2008/06/080625110820.htm>.
University of Illinois at Urbana-Champaign. (2008, June 26). Silicon Photonic Crystals Key To Optical Cloaking, Researchers Say. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2008/06/080625110820.htm
University of Illinois at Urbana-Champaign. "Silicon Photonic Crystals Key To Optical Cloaking, Researchers Say." ScienceDaily. www.sciencedaily.com/releases/2008/06/080625110820.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Who Will Failed Nuclear Talks Hurt Most?

Who Will Failed Nuclear Talks Hurt Most?

Reuters - Business Video Online (Nov. 25, 2014) With no immediate prospect of sanctions relief for Iran, and no solid progress in negotiations with the West over the country's nuclear programme, Ciara Lee asks why talks have still not produced results and what a resolution would mean for both parties. Video provided by Reuters
Powered by NewsLook.com
Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Reuters - Innovations Video Online (Nov. 25, 2014) A virtual flying enthusiast converts parts of a written-off Airbus aircraft into a working flight simulator in his northern Slovenian home. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Newsy (Nov. 23, 2014) Microsoft has robotic security guards working at its Silicon Valley Campus. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins