Ta2O5 coated PCF based tunable plasmonic sensor for sensitivity enhancement and wide range RI detection

Abstract

The present study reports on the numerical investigation carried out on a newly designed photonic crystal fiber (PCF) based plasmonic sensor for sensitivity enhancement and wide range refractive index (RI) detection. Gold (Au) is used as active plasmonic material and an additional overlayer of tantalum pentoxide (Ta₂O₅) is used. This study presents the detail sensor performance without and with the Ta₂O₅ overlayer by using finite element method (FEM) and the sensor performance is analyzed using surface plasmon resonance (SPR) phenomena. Maximum sensitivity of 9500 nm/RIU is reported in this study. Because of the tunable nature of the proposed sensor it is possible to detect a wide range of analyte RI from 1.32 to 1.40. Besides, coating of Ta₂O₅ overlayer results an enhancement of sensitivity. This study proposed a new designing technology to tune its operation range followed by sensitivity enhancement as per authors best knowledge. Moreover, as the wide detection range falls into the analyte of biological interest, so, after proper functionalization the proposed sensor can be treated with biorecognition elements and finally biofunctionalized sensing probe can be applicable as potential biosensor.