Since photo-induced polymerization of the ultra-violet (UV)-curing adhesive from a fluid state to a solid state is an exothermic process, the UV curing exothermic behavior can be regarded as a potential evaluation methodology to analyze UV-curing kinetics. Herein, a fiber Bragg grating (FBG)-based UV curing exothermic behavior monitoring is proposed to evaluate the UV-curing dynamic process and analyze a series of thermal and mechanical properties changes during curing. The exothermic behavior of the UV curing adhesive during curing and the feasibility of FBG-based curing kinetic analysis scheme are verified experimentally, full cycle cure monitoring of the UV curing adhesive can be realized by this FBG-based curing kinetic analysis scheme, and the UV-curing kinetics of four different types of the UV curing adhesive are corresponding to different exothermic behaviors. Compared with curing process evaluation based on refractive index variation, this FBG-based exothermic behavior monitoring has the ability to extract more details of the curing process, and some curing stages with negligible refractive index changes also can be distinguished. By using this proposed scheme, the UV-curing dynamic process and multiple characteristic parameters, such as curing time, time constant, transient temperature rise, and residual stress, can be evaluated, which may contribute to evaluating and analyzing UV-curing kinetics more comprehensively.

Since high efficiency and zero-carbon emission, hydrogen, as a clean energy carrier, is potentially an alternative fuel. Unfortunately, hydrogen is a gas with a high diffusion coefficient, wide explosion limit, and low ignition energy. Thus, to ensure the safe use of hydrogen, accurate and rapid monitoring of hydrogen leakage and abnormal concentration change must be addressed immediately, which is a critical scientific and technical problem. Therefore, we propose an optics-mechanics coupling fiber hydrogen sensor without electricity-related hazard factors. This proposed fiber hydrogen sensor is constructed by combining optics-mechanics coupling, specific adsorption of hydrogen to the surface of palladium (Pd), and Fabry-Pérot (F-P) interference mechanism; the optics-mechanics coupling is aroused by hydrogen-induced stress in the suspended Pd film, which functions as an F-P resonator mirror and a hydrogen-sensitive material. According to this configuration and principle, we achieve efficient and high-selective hydrogen detection at room temperature. This optics-mechanics coupling-based fiber hydrogen sensor is characterized by the high sensitivity (0.397 nm/1%), extensive dynamic range (0.5%–3.5%), 8 s response time, and 16 s recovery time. Hence, as an intrinsically safe hydrogen sensor with the high sensitivity and quick response, this optics-mechanics coupling-based fiber hydrogen sensor can be widely used in the hydrogen energy industry chain for rapid and high-performance hydrogen detection.