Performance analysis, optimization and structural modification of nano-scale grating configuration for Surface Plasmon Polariton based sensing

Abstract

In this paper, we have presented our study on the use of nano-scale grating coupling structure to excite Surface Plasmon Polariton (SPP) for biosensing, which, despite its comparatively less popular implementation in this field holds substantial potential for improvement. We have used Gold as the noble metal to generate and optimize the resonance between plasmons and electromagnetic wave. We have presented several noteworthy characteristics of this particular structure that can be taken into consideration while designing a biosensor/sensor with specific sensing requirements. The results presented here are obtained from a thorough numerical simulation using finite element modelling of the problem via `Wave Optics' module of the `COMSOL Multiphysics' software. Spectral responses of the sensor configuration in energy domain, with varying analytes and structural properties have been evaluated and their pros and cons have also been observed and discussed. Finally, a modified grating structure has been presented that has more practically executing potential than the basic structure and can be optimized using the same principle as presented for the basic structure earlier.