Near-Field Manipulation And Metallic Cavity Assisted High Surface Enhanced Raman Scattering Detection

We propose a metallic cavity hole array of appropriate cavity depth for high surface enhanced Raman scattering (SERS) detection. The array structure is numerically investigated using finite difference time domain (FDTD) method to manipulate surface plasmon resonance near-fields and to correlate it explicitly with SERS signal. Resonant interaction of plasmon near-fields with Raman analyte (R6G) causes increase in Raman scattering cross-section, which, in turn, leads to high SERS. We consider metallic cavity array of various cavity depths(50 nm to 250 nm in a step of 50 nm) as an ideal system for the proof of concept. Our FDTD computational results are in good agreement with experimental evidences.