Highly sensitive refractive index measurement using speckle patterns in perfluorinated polymer optical fiber sensors

The pursuit of highly sensitive yet cost-effective technologies has intensified in the realm of optical sensors. This paper presents an innovative approach to refractive index measurement by employing a polished perfluorinated polymer optical fiber sensor. Leveraging the distinct optical properties of speckle patterns formed on the fiber's end-face, this sensor accurately discerns variations in refractive index within its surrounding media. The specific material properties of the fiber render it particularly suited for liquid analysis. The proposed sensors were successfully evaluated for refractive index values up to 1.511, developing robust calibration curves in the process. This research introduces a promising avenue for precise and efficient refractive index measurements, demonstrating the potential of speckle pattern-based perfluorinated polymer optical fiber sensors in diverse applications requiring meticulous liquid analysis.