Honeycomb-lattice plasmonic absorbers at NIR : anomalous high-order resonance

• We design, fabricate and characterize a plasmonic honeycomb lattice absorber with almost perfect absorption at 1140 nm over a wide incident angle range. This absorber also possesses a narrow-band, angle-and polarization-dependent high-order resonance in the short-wavelength range, with a bandwidth of 19 nm and angle sensitivity of 3 nm per degree. The nature of this high-order absorption band is analyzed through finite-element simulations. We believe it is due to Bragg coupling of the incident light to the backward-propagating surface plasmon polariton through the periodic modulation of the structure. Such fine absorption bands can find applications in plasmonic sensors and spectrally selective thermal emitters.

Nyckelord

Electromagnetic wave polarization

Honeycomb structures

Surface plasmon resonance

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)