Real Life Invisibility Cloaks May be Possible Thanks to "Spectral Cloaking"
Time to break out your Marauder's Map.
It’s easy to see a number of nefarious uses for devices that allow you to walk the earth undetected, from traversing the grounds of Hogwarts after lights out to liberating the contents of a nearby bank vault. But early stage invisibility cloaks may offer a number of tangible, Muggle-world applications as well.
That’s according to a team of researchers behind a new paper in the latest issue of Optica. In the paper, researchers say that their new method of manipulating lightwaves opens the door to tech that can cloak a three dimensional object from all sides, leading to vastly more sophisticated sensors and communication tools in the process.
And also, quite possibly (further down the line), real life invisibility cloaks.
“Our work represents a breakthrough in the quest for invisibility cloaking,” said José Azaña of National Institute of Scientific Research and one of the paper’s authors in a statement. “We have made a target object fully invisible to observation.”
What Is Spectral Cloaking?
When we see things, we’re really just viewing said object as it reacts to the light waves around it. Various cloaking techniques that exist already (like the technology behind so-called green screens) involve filtering out a certain color, or subverting or otherwise bending light waves so that an object appears like it’s no longer there. But these approaches usually lead to distortion when dealing with multi-colored objects.
The new approach outlined in Optics temporarily rearranges the colors in an object and how they appear in the spectrum of light around it. That way, light can propagate directly through a target as opposed to needing to go around it, eliminating the aforementioned distortion. It needs a great deal more development before we can wear these invisibility cloaks “Harry Potter style” but researchers say that they were able to develop the device using commercially available equipment.
“Conventional cloaking solutions rely on altering the propagation path of the illumination around the object to be concealed,” said Luis Romero Cortés, another of the paper’s authors in a statement. “Our proposed solution avoids this problem by allowing the wave to propagate through the target object.”
In their experiment, the authors successfully completed the process by shooting laser pulses through an optical filter. By transforming the light waves and then reverting them back, the scientists made the laser appear as if it had been sent through a non-absorbing medium.
Right now the technology can only be applied to light rays moving in a single direction. But this new technique could already in the shorter term open the door to a number of practical applications, for example helping computers and people process ever-larger and unwieldy sets of data.