Close

Search

Search Menu
Photonics Media Photonics Buyers' Guide Photonics Spectra BioPhotonics EuroPhotonics Vision Spectra Photonics Showcase Photonics ProdSpec Photonics Handbook
More News

Terahertz invisibility cloak created

Facebook Twitter LinkedIn Email Comments
Compiled by Photonics Spectra staff

A new cloaking material can render objects invisible in the terahertz range. While the design does not create an invisibility cloak for the visible spectrum, it could have applications in diagnostics, security and communications.

The cloak, created at Northwestern University, uses microfabricated gradient-index materials to manipulate the reflection and refraction of terahertz wavelengths. To render an object invisible, light must be manipulated so that it will neither scatter at an object’s surface nor be absorbed or reflected by it. To manipulate light in the terahertz frequency, Cheng Sun, an assistant professor of mechanical engineering, and his colleagues used a technique called electronic transfer microstereolithography to develop a metamaterial composed of prism-shaped structures less than 10 mm long.

The researchers used a data projector to project an image onto a liquid polymer, and then light to transform the liquid layer into a thin solid layer. Each of the prism’s 220 layers has holes that are much smaller than terahertz wavelengths, which means that they can vary the refraction index of the light and render invisible anything located beneath a bump on the prism’s bottom surface; the light then appears to be reflected by a flat surface.

The purpose of the newly created cloak was not to hide items but to gain a better understanding of how to design materials that can manipulate light propagation, Sun said.

Sun’s research into terahertz optics could lead to safer detection of certain kinds of cancers and to better ways of using terahertz scanning at airports.

Sun hopes to use the information gathered from the cloak to create its opposite: a terahertz lens. He has no immediate plans to extend his invisibility cloak to visible frequencies.

Results of his findings were presented at CLEO 2011 in Baltimore.

Photonics Spectra
Jul 2011
AmericascancerCheng SunCLEOcloaking materialCommunicationsdata projectordefensediagnosticselectronic transfer microstereolithographyIllinoisindustriallenseslight propagationliquid polymermechanical engineeringmetamaterialsmicrofabricated gradient-index materialsNorthwestern UniversityopticsPrismsResearch & TechnologysecurityTech Pulseterahertz invisibility cloakterahertz lensterahertz scanner

Comments
back to top
Facebook Twitter Instagram LinkedIn YouTube RSS
©2019 Photonics Media, 100 West St., Pittsfield, MA, 01201 USA, info@photonics.com

Photonics Media, Laurin Publishing
x Subscribe to Photonics Spectra magazine - FREE!
We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.