Review of the Status and Prospects of Fiber Optic Hydrogen Sensing Technology

Abstract

With the unprecedented development of green and renewable energy sources, the proportion of clean hydrogen (H2) applications grows rapidly. Since H2 has physicochemical properties of being highly permeable and combustible, high-performance H2 sensors to detect and monitor hydrogen concentration are essential. This review discusses a variety of fiber-optic-based H2 sensor technologies since the year 1984, including: interferometer technology, fiber grating technology, surface plasma resonance (SPR) technology, micro lens technology, evanescent field technology, integrated optical waveguide technology, direct transmission/reflection detection technology, etc. These technologies have been evolving from simply pursuing high sensitivity and low detection limits (LDL) to focusing on multiple performance parameters to match various application demands, such as: high temperature resistance, fast response speed, fast recovery speed, large concentration range, low cross sensitivity, excellent long-term stability, etc. On the basis of palladium (Pd)-sensitive material, alloy metals, catalysts, or nanoparticles are proposed to improve the performance of fiber-optic-based H2 sensors, including gold (Au), silver (Ag), platinum (Pt), zinc oxide (ZnO), titanium oxide (TiO2), tungsten oxide (WO3), Mg70Ti30, polydimethylsiloxane (PDMS), graphene oxide (GO), etc. Various microstructure processes of the side and end of optical fiber H2 sensors are also discussed in this review.

Assessment of the Influence of Protective Polymer Coating on Panda Fiber Performance Based on the Results of Multivariant Numerical Simulation

“…One important area of research is the detection of optical fiber faults in real time during operation [31], since fast response and accurate detection have good financial significance to support the design. However, a lack of design performance data has been reported by manufacturers [32].…”

Polarization Property Associated with Surface Plasmon Resonance in a Palladium Thin-Film Coated Aluminum Grating in a Conical Mounting and Its Application to Hydrogen Gas Detection

“…Among hydrogen sensors, optical approaches including fiber optics have promising advantages, such as the ability to operate in explosive environments due to electrical isolation and immunity from electromagnetic interference [ 2 , 3 ]. Surface plasmon resonance (SPR) sensors, which are a type of optical hydrogen sensor, have been studied for a significant period of time [ 4 ].…”

“…As SPR hydrogen sensors with a waveguide coupler, a channel waveguide [ 10 ], and an optical fiber [ 11 ] were proposed, within which, a thin Pd film was coated on a portion of the core, from which, the cladding was then removed. Furthermore, various types of optical fiber hydrogen sensors [ 3 ], such as multimode fibers [ 11 , 12 ], fiber gratings [ 13 ], and tapered fibers [ 14 ], have been actively developed, owing to their potential for remote and multiplex sensing [ 15 ]. A metal diffraction grating, coated with a thin Pd film on its surface, has been proposed as a hydrogen SPR sensor [ 16 ].…”

“…A metal diffraction grating, coated with a thin Pd film on its surface, has been proposed as a hydrogen SPR sensor [ 16 ]. SPR hydrogen sensors are based on a technology that integrates refractive index sensing with hydrogen sensitive materials such as Pd [ 3 ]. Hydrogen sensitive materials that sensitively, selectively, and quickly convert the absorption or adsorption of hydrogen into a change in their own refractive index have been extensively studied as transducers in the following SPR hydrogen sensors [ 3 , 17 ]: Pd alloys [ 18 , 19 ], multilayers including a Pd layer [ 12 , 20 ], Pd composite films [ 21 ], Pd nanofilms on photonic crystal [ 22 ], etc.…”

“…SPR hydrogen sensors are based on a technology that integrates refractive index sensing with hydrogen sensitive materials such as Pd [ 3 ]. Hydrogen sensitive materials that sensitively, selectively, and quickly convert the absorption or adsorption of hydrogen into a change in their own refractive index have been extensively studied as transducers in the following SPR hydrogen sensors [ 3 , 17 ]: Pd alloys [ 18 , 19 ], multilayers including a Pd layer [ 12 , 20 ], Pd composite films [ 21 ], Pd nanofilms on photonic crystal [ 22 ], etc. Furthermore, an accurate and simple technique for detecting the change in optical properties, caused by the exposure of a hydrogen sensitive material to hydrogen gas, could be essential for the practical application of SPR hydrogen sensors.…”