Fiber Optics-Mechanics Coupling Sensor for High-Performance Hydrogen Detection

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.