Sensitivity Enhancement of Ta₂O₅ Coated PCF Based Plasmonic Sensor for Glucose Sensing Application

The present study reports on the numerical investigation carried out on a uniquely designed tantalum pentoxide (Ta
₂
O
₅
) coated photonic crystal fiber (PCF) based plasmonic sensor for sensitivity enhancement and label-free biological analyte detection. A new approach is proposed to avail external sensing mechanism by introducing the solid core at fiber periphery. By analysing modal characteristics numerically using finite element method (FEM), the wavelength sensitivity is found to be increased with the increase of Ta
₂
O
₅
thin film thickness. Maximum increase in sensitivity is reported for Ta
₂
O
₅
thickness of 50 nm. Moreover, the minimum measurable deviation of the sensor lies of the order of 10
⁻⁵
representing an overall good sensing performance. The proposed fiber has good specificity, environmental stability, small size and feasible optical sensing properties which enables its suitability as plasmonic sensor. In later study, an appropriate sensing application of proposed fiber as glucose concentration (GC) sensor is investigated for Ta
₂
O
₅
thickness of 50 nm. From the detail study, sensitivity is found to be varied linearly with GC and an average sensitivity of 0.81429 nm/g/L is achieved.