Laser-induced near-field effect concentrates the laser energy to be enhanced on a localized area much smaller than the wavelength for nanoprocessing. Owing to the superhigh fabrication resolution, the laser near-field processing has been used for the surface nanostructuring to create photonic devices. The near-field processing is typically performed by using scanning optical microscope or scanning probe microscope combined with laser, while nano/microspheres provide the unique advantages of maskless, time-saving schemes.
In this paper, laser near-field reduction of metal ions assisted by silica spheres is presented for fabrication of plasmonic superlattices on silicon substrate, which can tune localized surface plasmonic resonance wavelengths from the visible to the near-infrared region by adjustment of the lattice periods. In the laser near-field reduction, the incident laser is tightly focused at the bottom side of the silica sphere to confine the reaction the in near-field.
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