Exposed-core localized surface plasmon resonance biosensor

We propose and numerically characterize an exposed-core photonic crystal fiber for biosensing applications. Surface plasmons are excited within gold (Au) strips, and titanium dioxide is employed to support adhesion of Au with glass. In consideration of ease of fabrication, only four air holes are used to simplify the sensor structure. Simulation results show an improved wavelength and amplitude sensitivity of 34,000 nm/RIU and 1170  RIU−1, respectively, that comes with a low confinement loss of 0.79 dB/cm. Results also indicate a low full width at half-maximum that contributes to high figure of merit of 310.