Invisibility cloaking in the optical

--Nature Materials press release

DOI: 10.1038/nmat2461

A major step towards the realization of invisibility in the visible region is reported online this week in Nature Materials. The study demonstrates cloaking in the optical region for wavelengths in the near-infrared part of the spectrum and moves us a step closer to invisibility in a region that can been seen by humans.

Although cloaking has been demonstrated recently for the microwave region, the device structure used for these cloaks makes scaling down to the small wavelengths of the visible region challenging. Xiang Zhang and colleagues have now achieved cloaking in the optical region by etching small nanoscale holes into a layer of silicon. The holes follow a complex pattern and are designed to hide an object underneath a small bump -- creating a so-called carpet cloak. Compared with previous realizations of cloaking, the present design shows low losses and broadband operation over a wide part of the near-infrared spectrum. This design also has the potential to readily scale towards the visible region.


Author contact:

Xiang Zhang (University of California at Berkeley, CA, USA)

Tel: +1 510 643 4978; Cell: +1 510 225 8559; E-mail: xiang@berkeley.edu

Invisibility cloak edges closer

--BBC News

Unlike previous such "cloaks", the new work does not employ metals, which introduce losses of light and result in imperfect cloaking... Link

Leap forward for invisibility cloaks

--Nature News

Invisibility 'carpets' that conceal objects by making bumps look flat can work under near-infrared light, two teams of physicists have shown. And making a similar device that shields objects in visible light should be relatively straightforward... Link

Invisibility Cloak for Almost-Visible Light

--ScienceNOW Daily News

An invisibility cloak that works for visible light might soon be in sight, now that a team has made one that works for the slightly longer wavelengths of near-infrared light. The cloak is only about a micrometer in size--a little snug for Harry Potter--but other researchers say it's a major advance.... Link

Berkeley Researchers Create an "Invisibility Cloak"

--US News and World Report

Never mind Harry Potter, researchers at Berkeley have made an invisibility cloak of their own. A team led by Xiang Zhang, a principal investigator with Berkeley Lab’s Materials Sciences Division and director of UC Berkeley’s Nano-scale Science and Engineering Center, has created a “carpet cloak” from nanostructured silicon that conceals the presence of objects placed under it from optical detection. While the carpet itself can still be seen, the bulge of the object underneath it disappears from view. Shining a beam of light on the bulge shows a reflection identical to that of a beam reflected from a flat surface, meaning the object itself has essentially been rendered invisible.... Link