Asymmetrical photonic crystal fiber based plasmonic sensor using the lower birefringence peak method

An asymmetrical configuration of hexagonal lattice photonic crystal fiber (PCF) based surface plasmon resonance (SPR) refractive index sensor is proposed. Instead of the typical confinement loss method, the lower birefringence peak method is considered to explore the sensing performance. The asymmetry in the core region induces birefringence that enhances the coupling efficiency between the core and surface plasmon polariton (SPP) mode. To form the strong SPR effect, both the gold layer and analyte layer are deposited on the external surface of the PCF. The proposed birefringent sensor exhibits the maximum wavelength sensitivity of 22,000 nm/RIU within broad analyte refractive index (RI) from 1.33 to 1.42. The sensing characteristics are carried out with the variation of several PCF structural parameters. Owing to enhanced sensitivity, the proposed sensor can be a potential candidate for biological and biomolecular analyte detection. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement