Design and Optimization of Tapered Optical Fiber Probes for SERS Utilizing FDTD Method

In this work, we report a strategy of Ag nanoparticle (Ag NP)-coated tapered optical fiber probes by finite difference time domain (FDTD) simulations. Investigation shows that the fiber-tip decorated NPs has excellent electric field enhancement and confinement light capabilities. Moreover, demonstrate effect key parameters such as tip radius, conical angle, NP size, gaps between them on enhanced utilizing typical excitation wavelengths 532, 633, 785 nm. To further improve electrical effect, noble metal substrate is introduced below apex, which exhibits higher generated tip-substrate coupling. The presence Au does not lead to significant change in plasma characteristic peak at 490 This study provides useful reference for fabrication with plasmonic nanostructures design robust fiber-optic Raman sensors.