ph5b00321_si_009.avi (1.13 MB)
Ultra Sensing by Combining Extraordinary Optical Transmission with Perfect Absorption
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posted on 2015-11-18, 00:00 authored by Thomas G. Mayerhöfer, Richard Knipper, Uwe Hübner, Dana Cialla-May, Karina Weber, Hans-Georg Meyer, Jürgen PoppExtraordinary optical transmission
and perfect absorption are two
plasmonic-based optical phenomenona that are both accompanied by high
local field enhancements that can be exploited for biological and
chemical sensing. Here we merge both phenomenona in a slit array metamaterial
perfect absorber consisting of a dielectric layer sandwiched between
two metallic layers of which the upper layer is perforated with a
periodic array of slits. Period and dimensions of the slits and thickness
of the dielectric layer are tuned in a way that virtually all light
of a certain wavelength incident on the surface passes through the
slits and is subsequently absorbed. As a consequence, light–matter
interaction is greatly enhanced in the slits. Thus, already small
concentrations of analytes down to a monolayer attached to the sidewalls
of the slits can be detected by refractive index sensing and identified
by their spectral fingerprints with a standard mid-infrared lab spectrometer.