Advanced Polymer Fiber Bragg Grating Sensors and Applications

Fiber Bragg grating (FBG) sensors fabricated in cyclic transparent optical polymer (CYTOP) fibers are emerging as promising alternatives to conventional silica and poly(methyl methacrylate) (PMMA) fiber sensors for certain applications. CYTOP FBGs offer higher sensitivities, greater fracture toughness, and increased flexibility in bending compared to silica sensors, while exhibiting significantly lower optical losses than PMMA-based fibers. This review summarizes the reported response characteristics of CYTOP FBG sensors to strain, temperature, humidity, and ionizing radiation, and examines the role of thermal annealing and pre-straining in enhancing performance and reliability. Recent experimental demonstrations highlight their suitability for diverse sensing applications requiring compact size, high fracture toughness, multiplexing capability, enhanced sensitivity, and multi-parameter functionality. The findings aim to support future innovation in integrated sensor platforms and encourage further research into CYTOP-based fiber technologies.