Analyte-filled core self-calibration microstructured optical fiber based plasmonic sensor for detecting high refractive index aqueous analyte

•This sensor can detect analyte with a refractive index higher than that of the host material.•The sensor demonstrates high linearity and accuracy.•The detection method is that measuring the resonant wavelength and transmission intensity of peak 1 and peak 2 for different aqueous analytes simultaneously.

This paper presents a theoretical investigation on an analyte-filled core self-calibration microstructured optical fiber plasmonic refractive index sensor. The proposed microstructured optical fiber sensor introduces the concept of simultaneous detection in different ranges of wavelength because the sensing performance of the sensor in different wavelength ranges is relatively high, which will be useful for high accuracy measurement. The resonant peak 1 and peak 2 are stronger and more sensitive to the variation of analyte refractive index than any other peaks in this kind of microstructured optical fiber. An average refractive index sensitivity of −4354.3 nm/RIU (refractive index unit) and 2280 nm/RIU in the dynamic index range from 1.46 to 1.485 as well as −2660 nm/RIU and −4240 nm/RIU from 1.50 to 1.52 corresponding to the peak 1 and peak 2 can be obtained, respectively. The self-calibration sensor demonstrates high linearity and accuracy. The influence of the structural parameters on the plasmonic excitations is also studied, with a view of turning and optimizing the resonant spectrum.