SENSITIVITY OF REFRACTIVE INDEX SENSORS MADE USING NO-CORE TAPERED FIBRE: A COMPARATIVE ASSESSMENT

In this research paper, the authors discuss the development, structure and evaluation of a sensor system, for measuring index that is based on a tapered no core fibre (TNCF). To enhance the TNCF diameter's effectiveness various CO2 input powers were utilized to develop optical-based refractive index sensor. The tapered fibre waist of the TNCF design enables interaction with the surrounding medium thereby enhancing sensor sensitivity. Optimal taper shape selection was crucial in achieving sensitivity and a low limit of detection (LoD) in the TNCF design process. A CO2 laser was employed in the fabrication process to reduce the waist diameter for the TNCF. The sensor performance was evaluated by monitoring wavelength shift as a function of the surrounding medium refractive index. Experimental findings demonstrated that the TNCF-based refractive index (RI) sensor exhibited a LoD value of 0.127 RIU compared to NCFs 0.171 RIU and a higher sensitivity at 150.00259 ± 6.77632 nm/RIU versus NCFs sensitivity, at 42.30713 ± 1.20951 nm/RIU. Better performance was demonstrated by the TNCF-based RI sensor in terms of sensitivity, LoD, repeatability, and reversibility. This research advances the development of highly effective and versatile optical-based RI sensors for a wide range of real-time applications, thereby contributing to the ongoing advancement in fields like chemical analysis, biomedical diagnostics, and environmental monitoring. These sensors offer a significantly improved sensitivity and lower limit of detection compared to conventional sensors.