Dielectric loaded surface plasmon polariton properties of the Al2O3–Al nanostructure

Surface plasmons（SPs） in ultraviolet（UV） have attracted a great deal of attention because of their emerging applications in energy resources, environmental protection, and biotechnology. In this article, the dielectric loaded surface plasmon polariton（DLSPP） properties of the Al2O3–Al nanostructure are investigated theoretically. Sharp SP responses can be obtained in deep UV by setting an insulator grating on the aluminum film. It is found that the height of the grating element,the lattice parameter, and the filling factor can all modulate the DLSPPs of the Al2O3–Al nanostructure. We further find that this structure is sensitive to the embedding medium and can serve as a refractive index sensor in the UV region. The corresponding sensitivity increases with the decrease of the filling factor. The Al2O3–Al nanostructure may be useful for medical diagnostics and biotechnology in deep UV.