Featured Research

from universities, journals, and other organizations

Metamaterials: Leading light waves astray

Date:
June 4, 2013
Source:
Ludwig-Maximilians-Universitaet Muenchen (LMU)
Summary:
The development of structured synthetic materials with unusual electromagnetic properties, so-called metamaterials, promises to provide access to special physical effects of great technological interest. Metamaterials have already been fabricated that have a negative refractive index for electromagnetic waves -- bending them in the opposite sense to light waves entering water, for instance -- which opens up completely novel opportunities for the manipulation of light. One of these makes it possible, in principle, to create cloaking devices that seem to make objects disappear. Indeed, such an invisibility cloak has already been realized for microwaves.

The development of structured synthetic materials with unusual electromagnetic properties, so-called metamaterials, promises to provide access to special physical effects of great technological interest. Metamaterials have already been fabricated that have a negative refractive index for electromagnetic waves -- bending them in the opposite sense to light waves entering water, for instance -- which opens up completely novel opportunities for the manipulation of light. One of these makes it possible, in principle, to create cloaking devices that seem to make objects disappear. Indeed, such an invisibility cloak has already been realized for microwaves.

Related Articles


"The production of metamaterials for the manipulation of microwaves presents no special technological challenges -- but finding technically feasible ways of controlling the behavior of visible light in a similar fashion is a much more difficult task, because optical wavelengths are much shorter, on the order of half a micron," says Professor Heinz Langhals of the Department of Chemistry at LMU. The first attempts to overcome the technical hurdles depended on the use of elaborate nanotechnological methods that cannot easily be scaled up. However, Langhals and his colleague Alexander Hofer have now synthesized metamaterials based on organic molecules as building blocks. This approach has several advantages over the metallic nanostructures previously used, as the synthetic procedures are more efficient, the components are smaller and their structures can be varied at will. The special geometry required for their metafunction is created entirely by chemical means.

The wrong way around

"We utilize organic compounds with so-called conjugated double-bond systems, which allow the electrons to circulate freely within the molecule," Langhals explains. The necessary electromagnetic resonances arise from the presence in the compound of chromophores, which give the molecule a characteristic color. Chromophores resonantly absorb light in the visible portion of the spectrum. The crucial feature of the newly synthesized molecules is that they contain chromophore electron systems that are arranged in parallel, separated by spacers that permit length-dependent control of interactions between chromophores. This particular spatial configuration alters the refractive properties of the new materials, and in ways that give rise to novel effects. If the sign of the refractive index can be turned negative, light impinging on the material is bent in the opposite direction to light that interacts with a naturally occurring material or medium. "So metamaterials could guide rays of visible light around an object, effectively rendering it invisible," says Langhals.

Although this goal is still some way off, the new organic metamaterials provide the thread from which an invisibility cloak might one day be woven. The fabric itself can perhaps be put together with the help of suitable liquid-crystal structures. At all events, further work on the design of enhanced metamaterials is underway. "Such materials have a broad range of potential uses, and perhaps even more interesting than a simple cloaking function are applications in the area of light-based information technology -- the manufacture of ultrathin optical lenses, for instance. We can certainly expect some exciting developments in the future," Langhals concludes.


Story Source:

The above story is based on materials provided by Ludwig-Maximilians-Universitaet Muenchen (LMU). Note: Materials may be edited for content and length.


Journal Reference:

  1. Heinz Langhals, Alexander Hofer. Chromophores Arranged as ‘Magnetic Meta Atoms’: Building Blocks for Molecular Metamaterials. The Journal of Organic Chemistry, 2013; 130516154829005 DOI: 10.1021/jo4005662

Cite This Page:

Ludwig-Maximilians-Universitaet Muenchen (LMU). "Metamaterials: Leading light waves astray." ScienceDaily. ScienceDaily, 4 June 2013. <www.sciencedaily.com/releases/2013/06/130604094605.htm>.
Ludwig-Maximilians-Universitaet Muenchen (LMU). (2013, June 4). Metamaterials: Leading light waves astray. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/2013/06/130604094605.htm
Ludwig-Maximilians-Universitaet Muenchen (LMU). "Metamaterials: Leading light waves astray." ScienceDaily. www.sciencedaily.com/releases/2013/06/130604094605.htm (accessed March 3, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Tuesday, March 3, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Forensic Holodeck Creates 3D Crime Scenes

Forensic Holodeck Creates 3D Crime Scenes

Reuters - Innovations Video Online (Mar. 3, 2015) A holodeck is no longer the preserve of TV sci-fi classic Star Trek, thanks to researchers from the Institute of Forensic Medicine Zurich, who have created what they say is the first system in the world to visualise the 3D data of forensic scans. Jim Drury saw it in operation. Video provided by Reuters
Powered by NewsLook.com
Solar Plane Passes New Test Ahead of World Tour

Solar Plane Passes New Test Ahead of World Tour

AFP (Mar. 2, 2015) A solar-powered plane made a third successful test flight in the United Arab Emirates on Monday ahead of a planned round-the-world tour to promote alternative energy. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Electric Hydrofoiling Watercraft Delivers Eco-Friendly Thrills

Electric Hydrofoiling Watercraft Delivers Eco-Friendly Thrills

Reuters - Innovations Video Online (Mar. 2, 2015) The Quadrofoil is a high-tech electric personal watercraft that its makers call a &apos;sports car for the water&apos;. When it hits 10 km/h, the Slovenian-engineered Quadrofoil is lifted above the water onto four wing-like hydrofoils where it &apos;flies&apos; above the surface with minimal water resistance. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Everything You Need To Know About Mobile Payments In 2015

Everything You Need To Know About Mobile Payments In 2015

Newsy (Mar. 2, 2015) This year, mobile payments might finally catch on. Here are the things you need to know to stay on top of the latest developments. 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