Scientists Make An Invisibility Cloak. How Does This Work?
Researchers at the University of Rochester inspired perhaps by Harry Potter’s invisibility cloak, developed several ways—some simple and some involving new technologies—to hide objects from view.
The latest effort, developed at the University of Rochester, not only overcomes some of the limitations of previous devices, but it uses inexpensive, readily available materials in a novel configuration.
John Howell, a professor of physics at the University of Rochester, said:
“There’ve been many high tech approaches to cloaking and the basic idea behind these is to take light and have it pass around something as if it isn’t there, often using high-tech or exotic materials.”
Forgoing the specialized components, Howell and graduate student Joseph Choi developed a combination of four standard lenses that keeps the object hidden as the viewer moves up to several degrees away from the optimal viewing position.
“This is the first device that we know of that can do three-dimensional, continuously multidirectional cloaking, which works for transmitting rays in the visible spectrum,” said Choi, a PhD student at Rochester’s Institute of Optics.
“We use random on-off patterns to gain a small amount of position information while only minimally affecting the momentum of the photons”, explains Howell. “In much the same way as weak measurements, the random on-off patterns gain very little information about the position of the photons, but putting all the patterns together, we can learn about the images carried by the light.”
How exactly does it work? D-News explains:
Read more at the paper published in Physical Review Letters.