Analysis of a highly sensitive side polished hollow fiber plasmonic sensor and its application as a magnetometer

A highly sensitive hollow fiber (HF) sensor based on surface plasmon resonance is proposed and analyzed numerically. The sensor design involves a side polished HF with a nanoscale gold film deposited over the polished surface and an analyte filled core. The hollow portion of the fiber serves simultaneously as an analyte channel and core, when filled with high refractive index liquid. By analyzing the modal characteristics of the sensor using the finite element method, it is found that the wavelength sensitivity of the HF sensor varies from 25,642 nm/RIU (refractive index unit) to 60,000 nm/RIU in the range 1.45 to 1.47 RIU along with highest amplitude sensitivity of ${4231.7}\,\,{{\rm RIU}^{-1}}$4231.7RIU^-1. The minimum measurable alteration by the sensor lies in the order of ${{10}^{-6}}\,\,{\rm RIU}$10^-6RIU. The sensor also exhibits a high value of figure of merit (FOM) up to ${976}\,\,{{\rm RIU}^{-1}}$976RIU^-1 representing a very good overall performance. Moreover, due to the feasibility of design, the specific application of the sensor to magnetic field sensing is also demonstrated and achieved maximum sensitivity of 1361 pm/Oe.