Plasmonic Bragg Reflectors: Optimization and Application to Isolation

Plasmonic Bragg reflectors (PBRs) enhance extraordinary optical transmission (EOT) through arrays of subwavelength apertures. Here, we characterize PBRs with variable line depth, number of holes in the array, and number of lines. The experimentally determined optimum depth of 45 nm and the EOT enhancement saturation for only three PBR lines is discussed in terms of the surface plasmon polariton skin depth and scattering losses. We demonstrate the implementation of PBRs to effectively isolate two arrays of nanoholes, and to suppress the interaction between adjacent periodic array structures. As an application of this isolation, PBRs are used to isolate elements of multiple arrays in order to reduce interference, and thereby provide a more uniform spectral output from all regions of the superarray.