Performance Analysis of Bimetallic Layer With Zinc Oxide for SPR-Based Fiber Optic Sensor

Abstract

We present an efficient fiber optic SPR sensor consisting of bimetallic layers of silver (Ag) and gold (Au) in coordination with zinc oxide (ZnO) for refractive-index sensing in spectral mode. The performance of the sensor is explored in terms of electric field intensity, sensitivity, and the figure of merit theoretically as well as experimentally. Four kinds of sensors with layers of Ag/ZnO, Au/ZnO, Au/Ag/ZnO, and Ag/Au/ZnO over an unclad core of the fiber are studied. For simulation, two-dimensional multilayer matrix method along with geometrical optics is used. It is found that the sensor having layers of Ag/Au/ZnO with optimized thicknesses possesses maximum electric field intensity at the interface, large shift in the resonance wavelength, sharp SPR dip, and high value of the figure of merit. In addition, the additional layers of Au and ZnO can also be used for the tuning of resonance wavelength in the visible region of the electromagnetic spectrum and for the protection of Ag layer from oxidation and; hence, can improve the durability of the sensor. Further, ZnO layer can also be used to sense some of the gases.Index Terms-Bimetallic layer, figure of merit, optical fiber sensor, refractive index, sensitivity, surface plasmon resonance.

Effects of Incident Light Modes and Non-Uniform Sensing Layers on Fiber-Optic Sensors Based on Surface Plasmon Resonance

“…λ p = 1.4541 × 10 −7 m and λ c = 1.7614 × 10 −5 m for Ag [13]. The sensing layers of fiber-optic SPR sensors are always set to have a uniform distribution by other researches [14][15][16]. However, in actual operation, the sensing layers distribute unevenly both along circumferential and axial directions.…”

An Optical Fiber Refractive Index Sensor Based on the Hybrid Mode of Tamm and Surface Plasmon Polaritons

“…Silver is chosen as the metal material since it is well known as a good candidate for the SPR sensor. The dielectric constant of the silver layer is obtained by the following Drude free electron model [ 24 ]: where λ p = 1.4541 × 10 −7 m, λ c = 1.7614 × 10 −5 m.…”

Simultaneous estimation of vitamin K1 and heparin with low limit of detection using cascaded channels fiber optic surface plasmon resonance

“…Polybrene has been used for the sensing of heparin (Liu et al, 2015;Zhang et al, 2015) because polybrene neutralizes heparin involving chemical reactions/interactions (Montalescot et al, 1990;Tientadakul et al, 2013). In the proposed sensor for heparin sensing, ZnO has been introduced in the form of shell with polybrene as a central core because it has been recently reported by us that ZnO along with the sensing material increases the evanescent field and consequently the sensing performance of the SPR based sensor (Tabassum and Gupta, 2015). Additionally, high surface to volume ratio of polybrene@ZnO increases the access of heparin molecules to the polybrene molecules and neutralizes heparin molecules and changes the overall dielectric function of polybrene@ZnO to get sensed.…”