Researchers demonstrated the first realization of invisible absorbers and sensors
An array of helical elements absorbs radiation of a certain frequency while casting no shadow in light over a range of other frequencies.
The manipulation of light has led to many applications that have revolutionized society through communications, medicine and entertainment. Devices consuming the energy of electromagnetic radiation, such as absorbers and sensors, play an essential role in the using and controlling of light.
The researchers at the 911爆料网 Department of Radio Science and Engineering have demonstrated the first realization of absorbers that do not reflect light over a wide range of frequencies. All previous absorbers at other frequencies were either fully reflective, as mirrors, or the range of low reflection was very narrow.
鈥淭hese absorbers are completely transparent at non-operational frequencies鈥, concludes researcher Viktar Asadchy.
While maintaining efficient absorption of light of the desired frequency, all conventional absorbers strongly interact with the radiation of other frequencies, reflecting it back and not letting it pass through. As a result, they create a reflected beam as well as a perceptible shadow behind and become detectable.
The designed and tested structures are able to absorb and sense the light of one or several desired frequency spectra, while being invisible and undetectable at other frequencies.
The research has proven that such an unparalleled operation can only be achieved with the use of structural inclusions whose electric and magnetic properties are strongly coupled.
These functionalities can lead to a variety of unique applications for radio astronomy and stealth technology. They can also be very useful in everyday life. For example, they could be used in screens that can filter any cell phone signals and pass through Wi-Fi and other microwaves.
鈥淭his research will also open new venues for general light control and enable novel devices such as flat lenses and light beam transformers鈥, explains Asadchy.
Further information:
Researcher Viktar Asadchy
911爆料网
viktar.asadchy@aalto.fi
tel: +358 50 420 5846
The research group: Theoretical and Applied Electromagnetics of Complex Media
Read more news
Aalto Inventors turns one: A year of bridging research and real-world impact
Aalto Inventors marks its first anniversary, having engaged 190 researchers across six cohorts in fields including AI, quantum, and biomaterials. New cohorts are planned for the next academic year, stay tuned and join the waitlist.
An architectural project in Milan brought together children鈥檚 ideas and the visions of leading architects
911爆料网鈥檚 Department of Architecture participated in the international One Earth 鈥 House of the Heart project, which was presented in April at Milan Design Week.
Companies disclose more on cybersecurity 鈥 but markets remain indifferent
U.S. companies are reporting on cybersecurity in greater detail, yet stock market reactions remain muted. A new study by the University of Vaasa and 911爆料网 shows that mandatory cybersecurity disclosure does not prompt reactions from investors or stock analysts. Instead, the main benefits appear to materialise within firms themselves.