The guiding of light: A new metamaterial device steers beams along complex pathways

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Boston College researchers report developing a device that can bend light along complex pathways. An illustration shows a simulated electromagnetic wave propagation. Guided by a set of instructions delivered by the device, the wave curves around the profile of the eastern US while behaving as if traveling in a straight line. Credit: Optics Express

Using a composite metamaterial to deliver a complex set of instructions to a beam of light, Boston College physicists have created a device to guide electromagnetic waves around objects such as the corner of a building or the profile of the eastern seaboard.

As directed by the researchers' novel device, these beams continue to behave as if traveling in a straight line. In one computer simulation, Assistant Professor of Physics Willie J. Padilla and researcher Nathan Landy revealed the device could steer a beam of light along the boundary of the US, stretching from Michigan to Maine, down the seaboard, around Florida and into the Louisiana bayou, according to research published in the research journal Optics Express.

The researchers accomplished their feat by developing a much more precise set of instructions, which create a grid-like roadmap capable of twisting and turning a beam of light around objects or space. Their discovery is an extension of earlier metamaterial "cloaking" techniques, which have conjured up images of the Harry Potter character disappearing beneath his invisibility cloak.

Padilla and Landy report developing a space-mapping technique that delivers greater precision and efficiency guiding light along pathways that previously were too complex to sustain - from 90-degree angles to the rugged coastal profile of Maine. Furthermore, they've built this new device using relatively common dielectric materials, such as silicon.

"Our method combines the novel effects of transformational optics with the practicality of dielectric construction," Padilla and Landy report. "We show that our structures are capable of guiding light in an almost arbitrary fashion over an unprecedented range of frequencies."

The discovery builds upon a decade-long revolution in electromagnetics brought about by the emergence of metamaterials. Constructed from artificial composites, metamaterials have exhibited effects such as directing light at a negative index of refraction.

Researchers have combined metamaterials with artificial optical devices - also known as transformational optics - to demonstrate the "invisibility cloak" effect, essentially directing light around a space and effectively masking its existence. In addition, other researchers have used a method known as quasi-conformal mapping and very complex metamaterials to issue a somewhat imprecise set of instructions that create another space-cloaking effect.

Source: Boston College (news : web)

   

• mvg - Jul 31, 2009
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  "effectively masking its existence."
  
  
  
  Now masking the entire Eastern Seaboard might be a bit much--maybe they could go for a smaller goal, like masking Jersey City. (That would be an improvement!)
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• MorganW - Jul 31, 2009
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  to be sure I understand, can this physically mask tangible objects - such as people or machines? And does it only apply to visible light or does it render invisibility to other spectrums (i.e. radar, UV, etc)?
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• Anyone - Jul 31, 2009
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  Famous last words:
  
  "My computer SAID it would work!!"
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• gmurphy - Aug 01, 2009
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  MorganW, the work described here is concerned with channelling light, not invisibility. Invisibility (as we know it today) attempts to mask objects by allowing light to flow around their surface, rather than reflect off their surface. This work appears to investigate the plausibility of redirecting light around an arbitrary path, the ultimate mirage
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• otto1923 - Aug 01, 2009
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  "Also known as 'Project Rainbow', the Philadelphia Experiment was allegedly conducted by the U.S. Navy in 1943, as part of the military's initiative to render one of their ships invisible. The incident is said to have occurred at Philadelphia, Pennsylvania's Naval Shipyard on the USS Eldridge in front of witnesses who claim that the ship was invisible for a brief period. The U.S. Navy, however, denies that the experiment occurred.
  
  "There are various contradictory reports surrounding the Philadelphia Experiment... The most widely-told version of events is that test phases of the experiment first occurred during the summer of 1943 when the USS Eldridge first achieved partial invisibility. On 28 October 1943, the ship not only achieved complete invisibility, according to reports, but also teleported to Norfolk..."
  
  -I dont know about you all but I'm getting a little nervous ...
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• ThomasS - Aug 03, 2009
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  Invisibility devices will never be a reality.
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• MorganW - Aug 03, 2009
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  Is this how the aliens avoid our detection? Admit it - you were thinking it! :)
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• Birthmark - Aug 20, 2009
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  Very interesting.
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