A Low Refractive Index Microstructured Fiber Sensor with Wide Range Detection

Abstract

In order to achieve low refractive index detection in biomedical and material chemistry, a D-type microstructured optical ber (MOF) sensor based on surface plasmon resonance (SPR) is proposed in this paper. The sensor uses gold nano lm as sensing material between the core of the ber and the plasma on the surface, and is coated at the open-ring. Parametric analysis of the open-ring diameter, air hole diameter and thickness of the gold nano lm of the sensor was carried out by nite element method. The simulation results show that the sensor has a wavelength sensitivity of up to 10900 nm/RIU, the refractive index range of 1.20-1.34, optimal resolution of 9.17×10 − 6 RIU, and a decent gure of merit (FOM) is 46.2 RIU − 1 . The proposed MOF-SPR sensor has high wavelength sensitivity and low resolution in a similar detection range compared to existing studies. The sensor is capable of detecting not only low refractive index substances, such as liquid medical oxygen with a refractive index of 1.22 and sevo urane with a refractive index of 1.27, but also conventional refractive index substances such as water contamination with a refractive index near 1.33, providing a wide detection range. Therefore, the sensor is competitive in the detection of some low refractive index material detection elds.