<br/>We present results for the theoretical modeling of optimized nanopost plasmonic crystals (NPCs) as surface enhanced Raman spectroscopy (SERS) substrates. NPCs are composed of periodic arrays of dielectric posts (with cylindrical or rectangular cross-sections) upon which thin layers of gold are deposited. Characteristic frequencies of incident light can excite surface plasmons, resulting in electric field intensity enhancements . The intensity and resonances of NPCs enhancements can be tuned by varying size, shape, height, and periodicity of the nanoposts. We consider two novel NPCs, including, beveled cylindrical posts and optimized square posts. Using the finite-difference time-domain (FDTD) method, we simulated the average electric field intensities at both excitation and emission wavelengths of the NPCs to calculate a SERS enhancement response for various nanopost arrays. The FDTD method was verified by previous work to accurately calculate SERS responses and has been further applied towards these two novel geometries. These new NPC geometries were then optimized with respect to size, shape, height, and periodicity to yield greater enhancements. Novel structures such as beveled posts provide promise as NPCs due to their characteristic shape that allows for tunable excitation and emission wavelengths in order to selectively reproduce enhancements from plasmonic coupling.

Simulations of novel nanopost plasmonic crystal structures for SERS using FDTD methods

255th National Meeting (2018)

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