Navigation Links
Silicon photonic crystals key to optical cloaking, researchers say

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

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."


Contact: James E. Kloeppel
University of Illinois at Urbana-Champaign

Related biology technology :

1. Nanotube forests grown on silicon chips for future computers, electronics
2. Worlds most complex silicon phased-array chip developed at UC-San Diego
3. Align Technology, Inc. Ranked 23rd in Deloittes Technology Fast 50 Program for Silicon Valley Scientific & Medical Equipment, and Bio-Technology Companies
4. Job-related stress: NIST demonstrates fatigue effects in silicon
5. Move over, silicon: Advances pave way for powerful carbon-based electronics
6. UDs Appelbaum wins NSF Career Award for research on silicon spintronics
7. UCT Specialties (Formerly Petrarch) Announces the Release of Their New Product Guides for Silanes, Silicones, Platinum Catalyst and Glass Coatings
8. UM physicists show electrons can travel over 100 times faster in graphene than in silicon
9. Foldable and stretchable, silicon circuits conform to many shapes
10. The future of computing -- carbon nanotubes and superconductors to replace the silicon chip
11. Bluestar Silicones Introduces Three New Soft and Durable Liquid Silicone Rubber Products
Post Your Comments:
(Date:11/25/2015)... ... November 25, 2015 , ... Jessica Richman and Zachary Apte, ... their initial angel funding process. Now, they are paying it forward to other ... stage investments in the microbiome space. In this, they join other successful ...
(Date:11/24/2015)... , Nov. 24, 2015 Cepheid (NASDAQ: ... speaking at the following conference, and invited investors to ... NY      Tuesday, December 1, 2015 at 11.00 ... NY      Tuesday, December 1, 2015 at 11.00 ... Conference, New York, NY      Tuesday, ...
(Date:11/24/2015)... ... November 24, 2015 , ... ... But unless it is bound to proteins, copper is also toxic to cells. ... at Worcester Polytechnic Institute (WPI) will conduct a systematic study of copper in ...
(Date:11/24/2015)... Global, Inc., a worldwide provider of clinical research services headquartered in ... company has set a new quarterly earnings record in Q3 of ... for Q3 of 2014 to Q3 of 2015.   ... with the establishment of an Asia-Pacific office ... Kingdom and Mexico , with the ...
Breaking Biology Technology:
(Date:10/29/2015)... YORK , Oct. 29, 2015 ... technology, announced a partnership with 2XU, a global ... to deliver a smart hat with advanced bio-sensing ... and other athletes to monitor key biometrics to ... the strategic partnership, the two companies will bring together ...
(Date:10/27/2015)... 2015 Synaptics Inc. (NASDAQ: SYNA ), the ... has adopted the Synaptics ® ClearPad ® ... its newest flagship smartphones, the Nexus 5X by LG ... --> --> Synaptics works closely ... collaboration in the joint development of next generation technologies. ...
(Date:10/26/2015)... -- Delta ID Inc., a company focused on bringing secure ... announced its ActiveIRIS® technology powers the iris recognition feature ... NTT DOCOMO, INC in Japan . ... include iris recognition technology, after a very successful introduction ... 2015, world,s first smartphone to have this capability. ...
Breaking Biology News(10 mins):