Scientists have developed a stealth technology that, by using sound waves generated by lasers, can make opaque materials invisible, paving the way for new ways of camouflage objects.
Completely opaque materials are illuminated from above with a specific waveform-
The effect is that sound waves from the left side can pass through the material without obstacles.
The researchers say the technology can be applied to different types of waves and should be as effective as sound waves and sound waves.
Scientists have developed a stealth technology that, by using sound waves generated by lasers, can make opaque materials invisible, paving the way for new ways of camouflage objects.
Completely opaque materials are illuminated from above with a specific waveform-
The effect is that sound waves from the left side can pass through the material without obstacles.
The researchers say the technology can be applied to different types of waves and should be as effective as sound waves and sound waves.
Stefan roter from Wien University of Technology said: "complex materials such as sugar cubes are opaque because the sound waves inside them are scattered many times . " (TU Wien)in Austria.
"Light can enter and leave the object, but never pass through the medium in a straight line.
"Instead, it is scattered in all possible directions," Rott said . ".
Many different attempts have been made over the years to overcome this scattering, creating a "cloak of invisibility ".
"For example, special materials have been developed that can guide the sound waves around the object.
Or, experiment with objects that can shine on their own.
When an electronic display emits exactly the same light as it absorbs on the back, it may look invisible, at least when viewed at right angles.
"We don't want to re-wire and we don't want to restore them with extra monitors.
Our goal is to guide the original light through the object as if the object did not exist at all, "said Andre branderdt, one of the authors of the study.
"It sounds strange, but for certain materials, it is indeed possible to use our special wave technology," says Brandstotter . ".
In order for the laser to shine, the energy must be provided by the pump light.
Otherwise, the behavior of the laser material is like any other material --
It absorbs part of the light.
"The key point is to inject energy into the material in a space-customized way, so that the light is amplified in the right place, while allowing absorption in other parts of the material, konstantinos Makris of the University of Crete, Greece said.
"In order to achieve this, a beam with a completely correct pattern must be projected onto the material from above
In addition to the much higher resolution, it's like a standard video projector. "Makris said.
If this pattern corresponds exactly to the internal irregularities of the material that normally scatter light, then the projection from above can effectively close the scattering, and another beam of light passing through the material from one side can pass through, no obstacles, scattering or loss.
"Mathematically, it is impossible to find such a pattern at all," said Rott . ".
"Every object we want to make transparent must be illuminated with its own specific pattern --
According to the microscopic details of the internal scattering process, "he said.
"The method we are developing now allows us to calculate the correct pattern of any arbitrary scattering medium," he added . ".