RESUMEN
Here we report a simple and scalable soft-lithography-based templating technology for fabricating Au-covered oxide (titania and zirconia) gratings by using DVDs as a structural template. The resulting plasmonic gratings simultaneously exhibit very high surface plasmon resonance (SPR) sensitivity (up to â¼940 nm per refractive index unit, nm per RIU) and figure of merit (FOM, up to 62.5). The effects of thermal annealing of the templated oxide gratings on their final plasmonic properties have been systematically investigated by both experiments and finite-difference time-domain (FDTD) simulations. Higher SPR sensitivities and slightly reduced FOMs have been observed for the annealed gratings. Additionally, the amplitude of the SPR dips gradually decreases with increasing annealing temperatures. Scanning electron microscopy and X-ray diffraction show that the annealing process enlarges the crystal domain sizes of the oxides and smoothens the final plasmonic grating surface. Systematic FDTD simulations reveal that the SPR properties (e.g., dip amplitude) of Au-covered oxide gratings are significantly affected by the deformation of the track-pitch structure caused by thermal annealing, agreeing with the experimental results. The outstanding SPR performance combined with the high thermal stability of the crystalline oxides could make the templated plasmonic gratings a promising SPR platform for many important sensing applications, such as in situ probing heterogeneous catalytic reactions under realistic conditions.
RESUMEN
Here we report a simple and scalable bottom-up technology for assembling close-packed nanoparticle monolayers on both sides of a glass substrate as high-quality antiglare coatings. Optical measurements show that monolayer coatings consisting of 110 nm silica nanoparticles can significantly reduce optical reflectance and enhance specular transmittance of the glass substrate for a broad range of visible wavelengths. Both experiments and numerical simulations reveal that the antiglare properties of the self-assembled colloidal monolayers are significantly affected by the size of the colloidal particles.
RESUMEN
We report a systematic, experimental, and theoretical investigation on the surface plasmon resonance (SPR) sensing using optical disks with different track pitches, including Blu-ray disk (BD), digital versatile disk (DVD), and compact disk (CD). Optical reflection measurements indicate that CD and DVD exhibit much higher SPR sensitivity than BD. Both experiments and finite-difference time-domain simulations reveal that the SPR sensitivity is significantly affected by the diffraction order of the SPR peaks and higher diffraction order results in lower sensitivity. Numerical simulations also show that very high sensitivity (â¼1600 nm per refractive index unit) is achievable by CDs.