In this paper, a new kind of symmetrical aluminum (Al) nanotips structure based on localized rather traditional propagating surface plasmon polarizations (SPPs) focusing are designed and fabricated successfully. The simulation results about near-field distribution of electric field and reflectance calculations using finite-difference time-domain (FDTD) simulation theory are exhibited and then the device is fabricated mainly by coating Al films with the thickness of 100 nm on n-type doping silicon (Si), cutting into scale of 15mm×15mm by wafer dicing, electron beam lithography (EBL) exposure and ICP etching. The near-field focusing properties about small spot breaking the diffracting limitation with one order enhancement in the near-tip area of this structure are demonstrated experimentally using scanning nearfield optical microscopy (SNOM), and the comparisons to simulation results are analyzed, so as to reveal a potential application in capturing near-field focusing images quickly by applying exterior voltage signals based on our structure with nanotips.
Surface plasmon polarizations (SPP) is a nano-scale photon control technology which can converge the spread of oscillation electron driven by incident light. In recent years, SPP has become an advanced research hotspot and has been studied more and more widely. The convergence effect of SPP has extensive applications, such as Schottky barrier detector in which the higher power hotspot, the lower signal-to-noise ratio. In this paper, studies have been done about the interaction of light and matter. Different geometric shapes have been simulated, which were obtained by graphic clipping. Via comparing the power of the hot spot and the minimum location on the transmittance line, we concluded the relationship of the interaction and the structure. It’s found that every absorption peak corresponds a mode of LSPP spread. Therefore, we can design figure to control the spread of the SPP, and achieve fantastic goal. Finally, a typical figure with high power hotspot was given.