Abbreviated Journal Title
J. Appl. Phys.
PERFECT ABSORBER; REGIME; Physics, Applied
A thin-film selective absorber at visible and near infra-red wavelengths is demonstrated. The structure consists of an optically thick layer of gold, a SiO2 dielectric spacer and a partially transparent gold film on top. The optical cavity so formed traps and absorbs light at a resonance wavelength determined by the film thicknesses. Observed fundamental-resonance absorption strengths are in the range 93%-97%. The absorption red-shifts and broadens as the thickness of the top gold layer is decreased with little change in absorption strength. Thus, strong absorption with design-tunable wavelength and width is achieved easily by unstructured blanket depositions. Observed angle-dependent spectra agree well with the recent three-layer analytical model of Shu et al. [Opt. Express 21, 25307 (2013)], if effective medium approximation is used to calculate the permittivity of the top gold film when it becomes discontinuous at the lowest thicknesses.
Journal of Applied Physics
Nath, Janardan; Smith, Evan; Maukonen, Douglas; and Peale, Robert E., "Optical Salisbury screen with design-tunable resonant absorption bands" (2014). Faculty Bibliography 2010s. 5877.