A new cloaking technology has been developed at TU Wien: a special kind of material is irradiated from above in such a way that another beam of light can pass completely uninhibited.
How do we make an object invisible? Researchers from TU Wien (Vienna), together with colleagues from Greece and the USA, have now developed a new idea for a cloaking technology. A completely opaque material is irradiated from above with a specific wave pattern – with the effect that light waves from the left can now pass through the material without any obstruction. This surprising result opens up completely new possibilities for active camouflage. The idea can be applied to different kinds of waves, it should work with sound waves just as well as with light waves. Experiments are already in the planning.
Outwitting the Scattering of Light
“Complex materials such as a sugar cube are opaque, because light waves inside them are scattered multiple times”, says Professor Stefan Rotter (TU Wien). “A light wave can enter and exit the object, but will never pass through the medium on a straight line. Instead, it is scattered into all possible directions.”
For years many different attempts have been made to outwit this kind of scattering, creating a “cloak of invisibility”. Special materials have been worked out, for example, which are able to guide light waves around an object. Alternatively, also experiments have been performed with objects that can emit light by themselves. When an electronic display sends out exactly the same light as it absorbs in the back, it can appear invisible, at least when looked at in the right angle.
At TU Wien a more fundamental approach has now been chosen. “We did not want to reroute the light waves, nor did we want to restore them with additional displays. Our goal was to guide the original light wave through the object, as if the object was not there at all”, says Andre Brandstötter, one of the authors of the study. “This sounds strange, but with certain materials and using our special wave technology, it is indeed possible.”
The Laser Material
The team at TU Wien has spent years working on optically active materials, which are used for building lasers. To make the laser shine, energy has to be supplied by means of a pump beam. Otherwise, the laser material behaves just like any other material – it absorbs part of the incident light.
“The crucial point is to pump energy into the material in a spatially tailored way such that light is amplified in exactly the right places, while allowing for absorption at other parts of the material”, says Professor Konstantinos Makris from the University of Crete (previously TU Wien). “To achieve this, a beam with exactly the right pattern has to be projected onto the material from above – like from a standard video projector, except with much higher resolution.”
If this pattern perfectly corresponds to the inner irregularities of the material which usually scatter the light, then the projection from above can effectively switch off the scattering, and another beam of light travelling through the material from one side can pass without any obstruction, scattering or loss.
“Mathematically, it is not immediately obvious that it is at all possible to find such a pattern”, says Rotter. “Every object we want to make transparent has to be irradiated with its own specific pattern – depending on the microscopic details of the scattering process inside. The method we developed now allows us to calculate the right pattern for any arbitrary scattering medium.”
Light or Sound
Computer simulations have shown that the method works. Now the idea should be confirmed in experiments. Stefan Rotter is confident that this will be successful: “We are already discussing with experimentalists how this could be done. As a first step, we may test this technology with sound instead of light waves. Experimentally, they are easier to handle, and from a mathematical point of view, the difference does not matter significantly.”
Learn more: The Beam of Invisibility
The Latest on: Cloaking technology
[google_news title=”” keyword=”cloaking technology” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]- MIT Technology Reviewon April 27, 2024 at 9:51 am
This is what the priorities in the $95 billion spending package tell us about four military technologies and the way they’re reshaping how war is fought. Researchers are using generative AI and other ...
- The Long Comics History Behind X-Men's Sentinel Programon April 26, 2024 at 2:30 pm
For almost as long as they have been in the comics, the X-Men and mutantkind at large have been stalked by a world that hates and fears them—a world that manifested that hate in the metallic, ...
- 5 Best Paint Protection Films for Sports Carson April 26, 2024 at 10:57 am
In today’s digital age, small businesses face the exciting challenge of standing out in a crowded online marketplace. While this can seem daunting, the right digital marketing strategies can transform ...
- Silk, The Ancient Material With High-Tech Possibilitieson April 25, 2024 at 11:47 am
Silk: A World History” describes the unique qualities of silk that make it a sustainable material with a wide variety of applications.
- Sunfrog, Baby Fish, pseudonyms and the making of a collageon April 24, 2024 at 2:17 pm
Creter Copy Editor As the artistic community in Cookeville grows, long-time local artists are getting their shine. Local artist Sunfrog will present his first solo exhibit at the Tiny Cloak during May ...
- New stealthy submarine glider set for autonomous undersea missionson April 24, 2024 at 3:00 am
Northrop Grumman's Manta Ray uncrewed underwater vehicle aims to revolutionize undersea missions — it glides through the ocean without human assistance.
- Conspiracy theorists think Taylor Swift is performing Satanic ritualson April 23, 2024 at 4:00 am
A video accusing pop star Taylor Swift of engaging in “Satanic rituals” at her concerts has gone viral on Facebook and stirred outrage among conspiracy theorists. The video, p ...
- Pentagon eases cloak of secrecy around space warfare trainingon April 22, 2024 at 2:20 pm
WASHINGTON — The Pentagon has partially declassified some space electronic warfare technologies and exercises, a move seen as critical for enhancing U.S. Space Force training and fostering closer ...
- Realization of an ideal omnidirectional invisibility cloak in free spaceon April 22, 2024 at 10:00 am
A team led by Prof. Dexin Ye and Prof. Hongsheng Chen from Zhejiang University, and Prof. Yu Luo from Nanyang Technological University conducted research on the practical implementation of ...
- Scientists solved the 70-year-old mystery of an insect's invisibility coat that can manipulate lighton April 15, 2024 at 10:13 am
A team of researchers created the world's first synthetic brochosomes in a huge step towards invisibility cloaking technology.
via Google News and Bing News