Troy, N.Y. Researchers from Rensselaer Polytechnic Institute have developed a new nanotechnology-based "microlens" that uses gold to boost the strength of infrared imaging and could lead to a new generation of ultra-powerful satellite cameras and night-vision devices.
By leveraging the unique properties of nanoscale gold to "squeeze" light into tiny holes in the surface of the device, the researchers have doubled the detectivity of a quantum dot-based infrared detector. With some refinements, the researchers expect this new technology should be able to enhance detectivity by up to 20 times.
This study is the first in more than a decade to demonstrate success in enhancing the signal of an infrared detector without also increasing the noise, said project leader Shawn-Yu Lin, professor of physics at Rensselaer and a member of the university's Future Chips Constellation and Smart Lighting Engineering Research Center.
"Infrared detection is a big priority right now, as more effective infrared satellite imaging technology holds the potential to benefit everything from homeland security to monitoring climate change and deforestation," said Lin, who in 2008 created the world's darkest material as well as a coating for solar panels that absorbs 99.9 percent of light from nearly all angles.
"We have shown that you can use nanoscopic gold to focus the light entering an infrared detector, which in turn enhances the absorption of photons and also enhances the capacity of the embedded quantum dots to convert those photons into electrons. This kind of behavior has never been seen before," he said.
Results of the study, titled "A Surface Plasmon Enhanced Infrared Photodetector Based on InAs Quantum Dots," were published online recently by the journal Nano Letters. The paper also will appear in a forthcoming issue of the journal's print edition. The U.S. Air Force Office of Scientific Research funded this study. The pap
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Rensselaer Polytechnic Institute