A new kind of cloaking material that can render objects invisible in the terahertz range has been developed at Northwestern University.Though this design can't translate into an invisibility cloak for the visible spectrum, it could have implications in diagnostics, security, and communication.
The cloak, designed by Cheng Sun, assistant professor of mechanical engineering at Northwestern's McCormick School of Engineering and Applied Science, uses micro fabricated gradient-index materials to manipulate the reflection and refraction of light.
In order to manipulate light in the terahertz frequency, which lies between infrared and microwaves, Sun and his group developed metamaterials: materials that are designed at the atomic level.
Sun's tiny, prism-shaped cloaking structure, less than 10 millimetres long, was created using a technique called electronic transfer microstereolithography, where researchers use a data projector to project an image on a liquid polymer, then use light to transform the liquid layer into a thin solid layer.
Sun said the purpose of the cloak is not to hide items but to get a better understanding of how to design materials that can manipulate light propagation.
"This demonstrates that we have the freedom to design materials that can change the refraction index. By doing this we can manipulate light propagation much more effectively," he added.
The cloak, designed by Cheng Sun, assistant professor of mechanical engineering at Northwestern's McCormick School of Engineering and Applied Science, uses micro fabricated gradient-index materials to manipulate the reflection and refraction of light.
In order to manipulate light in the terahertz frequency, which lies between infrared and microwaves, Sun and his group developed metamaterials: materials that are designed at the atomic level.
Sun's tiny, prism-shaped cloaking structure, less than 10 millimetres long, was created using a technique called electronic transfer microstereolithography, where researchers use a data projector to project an image on a liquid polymer, then use light to transform the liquid layer into a thin solid layer.
Sun said the purpose of the cloak is not to hide items but to get a better understanding of how to design materials that can manipulate light propagation.
"This demonstrates that we have the freedom to design materials that can change the refraction index. By doing this we can manipulate light propagation much more effectively," he added.
