Fabrication and transmission properties of two-dimensional concavity metal/dielectric multilayer structure

Abstract Large-scale two-dimensional concavity metal/dielectric multilayer structure with submicrometer periodicity was fabricated by self-assembly of colloidal crystal, PDMS molding, and multilayer deposition into the PDMS cavity array, and its transmission properties were experimentally measured as the number of metal layer. For the samples with one metal layer, two transmission pass bands have been observed in the sample due to the excitation of surface plasmon polaritons (SPPs). The peak positions of the pass bands depend on the periodicity of the colloidal crystal. The transmission spectra highly depend on the incident angle for both s- and p-polarized light. For the samples with two or more metal layers, a new pass band due to interference appears. This band is not as sensitive to the incident angle for s- or p-polarized light as the SPP induced band is, and its position depends on the thickness of the metal and dielectric layer. As the number of metal layer increases, the intensity of the SPPs induced band decreases faster than that of the interference related band. For the samples with four metal layers, only the interference related band is clearly observed. The fabrication method introduced here also provides a low-cost approach to the fabrication of 2D cavity metal/dielectric multilayer structure, and the method would be useful in the hyperlens array fabrication.