2 research outputs found
Four-Fold Color Filter Based on Plasmonic Phase Retarder
We
present a plasmonic color filter based on periodic subwavelength
silver nanowires, capable of changing the output color by simple rotation
of a polarizer. The effect is enabled by a wavelength-dependent phase
shift near the plasmon resonance, giving rise to a wavelength-dependent
rotation of the incident polarization. Subsequent rotation of an analyzing
polarizer leads to an output of four distinct colors (e.g., yellow,
blue, purple, and red) and combinations thereof. The plasmon resonance
itself can be tuned throughout the visible spectral region by proper
choice of fabrication parameters
Color Rendering Plasmonic Aluminum Substrates with Angular Symmetry Breaking
We fabricate and characterize large-area plasmonic substrates that feature asymmetric periodic nanostructures made of aluminum. Strong coupling between localized and propagating plasmon resonances leads to characteristic Fano line shapes with tunable spectral positions and widths. Distinctive colors spanning the entire visible spectrum are generated by tuning the system parameters, such as the period and the length of the aluminum structures. Moreover, the asymmetry of the aluminum structures gives rise to a strong symmetry broken color rendering effect, for which colors are observed only from one side of the surface normal. Using a combination of immersed laser interference lithography and nanoimprint lithography, our color rendering structures can be fabricated on areas many inches in size. We foresee applications in anticounterfeiting, photovoltaics, sensing, displays, and optical security