The ability to identify different wavelengths -- or colors -- of the infrared spectrum would capture much more information about the objects being imaged, such as their chemical composition.
In a new study, a team lead by Maiken H. Mikkelsen, the Nortel Networks Assistant Professor of Electrical & Computer Engineering and Physics at Duke University, demonstrates perfect absorbers for small bands of the electromagnetic spectrum from visible light through the near infrared. The fabrication technique is easily scalable, can be applied to any surface geometry and costs much less than current light absorption technologies.
Once adopted, the technique would allow advanced thermal imaging systems to not only be produced faster and cheaper than today's counterparts, but to have higher sensitivity. It could also be used in a wide variety of other applications, such as masking the heat signatures of objects.
The study was published online Nov. 9 in Advanced Materials.
"By borrowing well-known techniques from chemistry and employing them in new ways, we were able to obtain significantly better resolution than with a million-dollar state-of-the-art electron beam lithography system," said Mikkelsen. "This allowed us to create a coating that can fine-tune the absorption spectra with a level of control that hasn't been possible previously, with potential applications from light harvesting and photodetectors to military applications."
"This doesn't require top-down fabrication such as expensive lithography techniques and we don't make this in a clean room," added Gleb Akselrod, a postdoctoral researcher in Mikkelsen's laboratory. "We build it from the bottom up, so the whole thing is inherently cheap and very scalable to large areas.