Abstract

We report the successful fabrication of infrared plasmonic metamaterial absorbers by electron beam lithography and the lift-off technique. The absorber consists of periodic arrays of gold (Au) nanostructures deposited on a stack of thin silica spacer and gold film (acting as a mirror) on a silicon wafer. At resonance, we numerically observed a strong field enhancement between the metallic nanostructures and the Au film, resulting in a strong confinement of incident light within the silica spacer and thus a high absorption of up to 80% at infrared wavelengths. Our experimental measurement for reflection coefficients are in excellent agreement with the full-wave simulation results. We show that the resonant absorption spectral response can be used for highly-sensitive, label-free refractive-index biosensors. By tailoring various forms of nanostructures, we investigate their refractive index sensitivities to identity the most sensitive sensor at specific infrared wavelengths.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call