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

Abstract

A surface plasmon resonance sensor based on double-sided 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.