title: Coexistence of positive and negative refractive index sensitivity in the liquid-core photonic crystal fiber based plasmonic sensor.
abstract: We present and numerically characterize a liquid-core photonic crystal fiber based plasmonic sensor. The coupling properties and sensing performance are investigated by the finite element method. It is found that not only the plasmonic mode dispersion relation but also the fundamental mode dispersion relation is rather sensitive to the analyte refractive index (RI). The positive and negative RI sensitivity coexist in the proposed design. It features a positive RI sensitivity when the increment of the SPP mode effective index is larger than that of the fundamental mode, but the sensor shows a negative RI sensitivity once the increment of the fundamental mode gets larger. A maximum negative RI sensitivity of -5500nm/RIU (Refractive Index Unit) is achieved in the sensing range of 1.50-1.53. The effects of the structural parameters on the plasmonic excitations are also studied, with a view of tuning and optimizing the resonant spectrum.
authors.affiliation: Wuhan National Laboratory for Optoelectronics, Wuhan 430074, Hubei, China.
authors.forename: Binbin
authors.initials: B
authors.lastname: Shuai
authors.forename: Li
authors.initials: L
authors.lastname: Xia
authors.forename: Deming
authors.initials: D
authors.lastname: Liu
mesh_terms: D015374:Biosensing Techniques; D003198:Computer Simulation; D004867:Equipment Design; D005336:Fiber Optic Technology; D020342:Finite Element Analysis; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D008962:Models, Theoretical; D017785:Photons; D012031:Refractometry / Q000295:instrumentation* / Q000379:methods; D012834:Silver / Q000737:chemistry; D020349:Surface Plasmon Resonance
chemical_list: D012834:Silver; D006046:Gold