Flexible Polymer Materials: Thermoset or thermoplastic elastomers (e., PDMS - polydimethylsiloxane), biocompatible hydrogels, natural polymers such as spider silk and silk fibroin. Fiber optic sensors are sophisticated devices that utilize light transmitted through optical fibers to detect and measure various physical, chemical, and environmental parameters. These sensors stand out for their small size, immunity to electromagnetic interference, and capability to function in. Fiber optic sensors have gained popularity over the last few decades. Introduction In this Special Issue, we aim to focus on all aspects of the recent research and development related to fiber optic sensors. Recent advances in fiber-based sensing technologies have enabled both fundamental. Radiation absorption excites an orbital electron to a higher energy level.