High sensitivity refractive index sensor with wide detection range and high linearity based on LSPR in hollow-core anti-resonance fiber

• The wide detection range of the refractive index sensor is 1.28–1.44. • High average sensitivity is around 14996.81 nm/RIU in the wide detection range. • High linearity of 0.99991 is also achieved in the wide detection range. • The maximum figure of merits of the sensor reaches 139.78 RIU −1 . A high sensitivity refractive index sensor based on local surface plasmon resonance in hollow-core anti-resonance fiber with wide detection range and high linearity is proposed. Gold nanowires are filled in two symmetric cladding tubes of the hollow-core anti-resonance fiber, and analyte is filled in the fiber core area. A full vectorial finite element method is used to design and analyze the hollow-core anti-resonance fiber sensor based on local surface plasmon resonance. High average wavelength sensitivity around 14996.81 nm/RIU is achieved in a wide refractive index detection range of 1.28–1.44 with high linearity of 0.99991. The maximum figure of merits of the sensor reaches 139.78 RIU −1 . This separate filling of analyte and sensitive material opens up convenience applications for microfluidic detection. Due to its high sensitivity, wide detection range and high linearity of response, the proposed refractive index sensor also has potential applications in environmental protection, food safety and biosensing.