Invisibility Cloaks: A Reality

Whether its the powers of invisible woman in fantastic four or the invisibility cloak in harry potter we have all at one point dreamt about having the power to somehow be invisible, who wouldn’t want to snoop around without the fear of being seen? If you are one such person then science has good news for you, invisibility cloaks are now a reality. Researchers at university of Rochester have made a cloaking device that works in three dimensions using no specialized equipment but only four standard lenses.

 Professor John Howell along with a graduate student Joseph Choi have developed the “Rochester Cloak” by using the basic idea of manipulation of light waves, forcing them around an object and obscuring it from the view. This is done by combining four standard optical lenses in a way that keeps the object hidden, even as the viewer moves side to side. "This is the first device that we know of that can do three-dimensional, continuously multi-directional cloaking, which works for transmitting rays in the visible spectrum," Choi said.

the Rochester cloak array, showing how the light bends

Unlike the previous cloaking devices this one partially solves the problem of viewpoint, leaving the background undisturbed, undistorted and without any sort of warping. The lenses are placed at such a distance from each other that forces light to act in the desired way. First, one lens focuses the light into one fine point on the second lens, the second lens does the same for the third lens and so on. Giving the result that the object in the ring shaped array of light is hidden from the view.

However at the moment the setup is not perfect. “This cloak bends light and sends it through the center of the device, so the on-axis region cannot be blocked or cloaked,” said Choi. This means that the cloak region is shaped like a doughnut. But Howell and Choi have already started working on more complicated versions to solve this problem.

Although this cloaking device is far from perfect but it is still a step in the right direction and in a decade or so we maybe witnessing the invention of invisibility cloaks that we have seen only in sci-fi movies yet.

Aside from spying and intelligence purposes Choi and Howell have other uses in mind for the invisibility cloak like allowing a surgeon to operate on a patient without having the view hidden by their own hands or allowing truck drivers to see through blind spots. The possibilities are endless.

Because of the fact that this whole setup is pretty simple, this can be accomplished at home as well. Anyone can get a bunch of lenses and give it a try and for this purpose Choi and Howell have published a tutorial for an at-home do-it-yourself cloaking device. If you want to give it a go then click here.