Star-Trek-style ’space-time invisibility cloak’ comes a step closer

WASHINGTON - A person moving from one place to another without being detected may sound more like sc-fi, but metamaterials can make this possible.

Developed by the researchers from Imperial College London, metamaterials can be artificially engineered to distort light or sound waves.

With conventional materials, light typically travels along a straight line, but with metamaterials, scientists can exploit a wealth of additional flexibility to create undetectable blind spots.

Previously, it was shown that metamaterials could be used to make an optical invisibility cloak.

Now, a team led by Martin McCall has mathematically extended the idea of a cloak that conceals objects to one that conceals events.

“Light normally slows down as it enters a material, but it is theoretically possible to manipulate the light rays so that some parts speed up and others slow down,” said McCall, from the Department of Physics at Imperial College London.

When light is ‘opened up’ in this way, rather than being curved in space, the leading half of the light speeds up and arrives before an event, whilst the trailing half is made to lag behind and arrives too late.

The result is that for a brief period the event is not illuminated, and escapes detection. Once the concealed passage has been used, the cloak can then be ‘closed’ seamlessly.

“If you had someone moving along the corridor, it would appear to a distant observer as if they had relocated instantaneously, creating the illusion of a Star-Trek transporter. So, theoretically, this person might be able to do something and you wouldn’t notice!” said McCall.

Co-author Paul Kinsler developed a proof of concept design using customised optical fibres, which would enable researchers to use the event cloak in signal processing and computing. (ANI)