Surface Plasmon Resonance Sensor Based on Double-Sided Polished Microstructured Optical Fiber With Hollow Core

Abstract

A surface plasmon resonance sensor based on doublesided polished microstructured optical fiber with hollow core is put forward for refractive index sensing. Two gold films parallel to each other attached to the polished surface act as microfluidic sensing channels for the analyte. The artificially introduced air hole can facilitate the phase matching between the core mode and the plasmon mode. The sensitivities of the proposed sensor are investigated by the wavelength, amplitude and phase interrogation methods when the analyte refractive index increases from 1.33 to 1.34. In contrast to the D-shaped design, the double-sided polished structure demonstrates narrower resonance spectral width and greater phase sensitivity. Moreover, the numerical results indicate that the proposed sensor shows a good stability in the fabrication tolerances of ±5% of the thickness of gold film and the depth of polishing, respectively. Index Terms-Fiber optics sensors, surface plasmon resonance, microstructured optical fiber, refractive index sensors. I. INTRODUCTION S URFACE plasmon resonance (SPR) is the excitation of the surface plasmon coupled with the oscillations of free electron density between the metal and dielectric [1]-[5].

Surface Plasmon Resonance Sensor Based on Double-Sided Polished Microstructured Optical Fiber Coated With Graphene-on-Silver Layers

“…Compared with the inside gold coated structure, the proposed structure has greater wavelength sensitivity when n a varies from 133 to 1.34 [22]. Among the four structures in Table III, the proposed structure has the largest amplitude sensitivity because it exhibits a narrower spectral width [22], [29], [30].…”

“…can be obtained by detecting the power of transmitted light at a certain wavelength (λ). The amplitude sensitivity (S A ) is defined as [29]…”

“…Taking advantage of these structures, in this paper, we propose a SPR sensor based on double-sided polished MOF coated with graphene-on-silver layers for detecting the change of refractive index (RI). The main advantage of employing the double-sided polished structure is that it can provide the resonance peak with narrower spectral width, and thus contributing to a better signal to noise ratio (SNR) and sensing resolution [29]. One reason of using graphene is that it can prevent the oxidation and corrosion of silver [24]- [26], [28].…”

Orthogonal-Sided Polished Microstructured Optical Fiber-Based SPR Sensor for Simultaneous Measurement of Temperature and Refractive Index

“…In the MOF-SPR sensors, the thickness of the metallic layer is an important parameter that can influence the SPR spectra and the sensor performances [12]- [16], [19]- [21], [26]- [28], [30], [34]- [36]. In Figs.…”

“…This peak behavior is caused by the fact that the thicker gold layer can weaken the energy transfer from the core modes to the SPP modes, as seen from insets A-C in Figs. 6 and 7, and also increase the n eff of the SPP modes at the metal dielectric interface, and thus requiring longer wavelength to match the phases of the core modes and SPP modes [12]- [16], [19]- [21], [26]- [28], [30], [34]- [36].…”