Analysis of Sinusoidal Silver Corrugation over D-Shaped Fiber Optic Plasmonic Sensor

A D-shaped fiber optic plasmonic refractive index sensor with sinusoidal corrugation is proposed. Proposed structure is analyzed for different refractive indices of the sample at the optimized corrugation parameters. Electric field is confined to core and further coupled to metallic sinusoidal corrugation for the sample refractive ≥ 1.37. However, proper dip of the transmittance curve is achieved for the sample refractive ≥ 1.38. It is seen that the resonance wavelength, shift in resonance wavelength, bandwidth, and penetration depth of field in the sample increase whereas minimum transmittance and propagation length reduce by increasing the refractive index of the sample beyond 1.37. Further, the proposed sensor localizes the penetration depth in the sample near to 150 nm and propagation length at the metal-sample interface near to 5 µm. The proposed sensor can be used in the event of specific detection of smaller biomolecules by tuning the corrugation parameters.