An invisibility time cloak has been developed, and no — not by Harry Potter or some other wizard, but by scientists. The cloak is able to hide events in a continuous stream of light.
If it doesn’t use magic, then how does the invisibility time cloak work?
The speed of light, represented in the form of a beam of light, is manipulated within optic fibers. Any action which then takes place during this “hole in time” cannot be detected.
The time cloak that the scientists created tears a hole in time itself, allowing data to be hidden and transmitted over fiber optic cables without ever showing it was there.
The research the scientists did to create their current version of an invisibility time cloak built upon a time cloak described last year. Then, the story broke that scientists had invented a time cloak, but that version was only able to hide single brief events of time in an optical beam.
Information and data is hidden by the new type of invisibility cloak, rather than the spatial objects other such efforts have concentrated on hiding. Events, rather than objects, are hidden.
A Purdue University team in Indiana has shown events in the path of a continuous light beam can be hidden by having several “holes in time” utilized.
The researchers were able to cloak nearly half the data the researchers put in the beam of light’s path, which they would otherwise be able to detect.
Cloaking, as the name suggests, is where an object or event is hidden from vision. Frequencies of light or sound can be cloaked. Stealth war planes, for example, can be difficult to detect on enemy radar.
“We were able to push the light forward and back using commercial telecoms components, that are controlled by electrical signals,” said Andrew Weiner, co-author of the paper.
“When one sends high-speed data over an optical fibre in the existing infrastructure, in many cases it’s just 1’s and 0’s (binary code).”
Light is bent by using phase modulators, a common piece of optical equipment. The cloaking device hides data in time itself.
This device is based on a principle known as the Talbot effect. This effect creates repeated self-images of a grating when light passes through it from different directions. The cloaking device creates a laser pulse packed with data, then closes it back up again.
There are two phase modulators at each end of the communications stream, These speed up the front end of waves and slow down their trailing edges. When the crest from one wave packet aligns with the trough of another wave, it makes it look like no signal was ever sent.
Andrew Weiner of Purdue University was the leader of the team of researchers. The team discovered that this effect could cloak transmitted data at 12.7 gigabits per second – fast enough for fiber optic communications.
Though called a time cloak, it’s actually “not a manipulation of time, it’s a manipulation of light” according to Greg Gbur, a specialist in optical physics at the University of North Carolina at Charlotte.
The researcher was not involved in the study, but stated it showed a huge advance in the work on the time cloak.
The research has several possible applications, such as in making data more tamper proof. It could also be used to monitor “undesirable communication” and could be used by governments or large firms that handle sensitive or confidential information.
In theory, the invisibility cloak could even one day be used by a thief to rob a bank. The CCTVs would not record his image until after he was gone.
The study is published in the journal Nature of June 5.
Who needs wizardry when there’s science around?
Written by: Douglas Cobb