posted on 2018-09-12, 00:00authored bySayan Chandra, Daniel Franklin, Jared Cozart, Alireza Safaei, Debashis Chanda
With advancements
in infrared detection technology, there is a
need for fast, switchable infrared camouflage. Here, we report an
adaptive infrared camouflage system that can be engineered to operate
at any desired wavelength in the technologically relevant, infrared
transparent 3–5 and 8–12 μm bands. Adaptive camouflage
is actuated by exploiting the semiconductor to metal phase transition
in VO2, which modifies the reflection spectra of the multilayered
cavity-coupled plasmonic system. The temperature-dependent permittivity
of VO2 is calculated using effective medium theory to investigate
its role in the optical response of the system. Finally, we show for
the first time active thermal camouflage of multispectral infrared
information that was encoded on a designer surface comprised of sub
20 μm pixels. Our results demonstrate the versatility of the
design, which can lead to future research and applications of high
definition adaptive infrared tagging, camouflaging, and anticounterfeiting
efforts.