Multiplexable Low-Temperature Fiber Bragg Grating Hydrogen Sensors

et al. 2015

Photonic Sens

Abstract:A fiber-optic Fabry-Perot hydrogen sensor was developed by measuring the fringe contrast changes at different hydrogen concentrations. The experimental results indicated that the sensing performance with the Pd-Y film was better than that with the Pd film. A fringe contrast with a decrease of 0.5 dB was detected with a hydrogen concentration change from 0% to 5.5%. The temperature response of the sensor was also measured.

“…Palladium (Pd) has been widely used in hydrogen sensors because of its high sensitivity and selective affinity [7][8][9][10]. The further Pd-Y film was used for hydrogen sensing [11].…”

Section: Introductionmentioning

confidence: 99%

Fiber-optic Fabry-Perot hydrogen sensor coated with Pd-Y film

Liu

et al. 2015

Photonic Sens

“…At present there are several kinds of optical fiber hydrogen sensors, such as evanescent sensor [1][2][3][4][5][6], micro-mirror sensor [7][8], surface plasmon resonance (SPR) sensor [9], acoustic resonator sensor [10], and fiber Bragg grating (FBG) sensor [11][12][13][14]. Although the evanescent and micro-mirror sensors are simple and inexpensive, their multiplexing capability is quite limited.…”

Section: Introductionmentioning

confidence: 99%

Review on optical fiber sensors with sensitive thin films

Yang

Dai

2011

Photonic Sens

Abstract:The combination of fiber optics with nano-structure technologies and sensitive thin films offers great potential for the realization of novel sensor concepts. Miniatured optical fiber sensors with thin films as sensitive elements could open new fields for optical fiber sensor applications. Thin films work as sensitive elements and transducer to get response and feedback from environments, in which optical fibers are employed to work as signal carrier. This article presents some research work conducted at the National Engineering Laboratory for Optical Fiber Sensing Technologies in recent years. Concrete examples are: Pd/WO 3 co-sputtered coating as sensing material for optical hydrogen sensors shows robust mechanical stability and meanwhile good sensing performance; TbDyFe magnetostrictive coating directly deposited on fiber Bragg grating (FBG) demonstrates its possibility of miniature optical magnetic field/current sensors, and 40-pm shift of the FBG wavelength happens at a magnetic field order of 50 mT.

“…Due to the explosion-proof nature of optical fiber, many Pdcoated optical fiber sensors have been demonstrated for single-point hydrogen sensing, including Pd-coated mirror, 1 side-polished and tapered fiber sensor, 2,3 Fabry-Perot interferometer (FPI), 4 and fiber Bragg gratings (FBGs). [5][6][7][8] To enhance the hydrogen absorption rate of Pd in low temperature, different in-fiber heating techniques have been developed using long period grating (LPG), 5 double-clad fiber (DCF), 6 and high attenuation fiber (HAF). 7,8 A more challenging issue is to develop distributed sensing technology, so sophisticated hydrogen system can be completely monitored using a single interrogation unit.…”

mentioning

confidence: 99%

“…[5][6][7][8] To enhance the hydrogen absorption rate of Pd in low temperature, different in-fiber heating techniques have been developed using long period grating (LPG), 5 double-clad fiber (DCF), 6 and high attenuation fiber (HAF). 7,8 A more challenging issue is to develop distributed sensing technology, so sophisticated hydrogen system can be completely monitored using a single interrogation unit. Multipoint quasi-distributed hydrogen sensing has been reported with FPI sensors multiplexed in parallel with fan-out fiber coupler 4 and FBG sensors multiplexed in serial on a single fiber, 5-8 both of which provide excellent centimeter spatial resolution with their compact sizes.…”

mentioning

confidence: 99%

“…Temperature crosssensitivites can be discriminated from the hydrogen strain responses by employing polarization maintained fiber as FUT. 14 Furthermore, using multimode fibers and high attenuation fibers, optical on-fiber heating [5][6][7][8] can be employed instead of electrical heating to completely eliminate the spark hazard, but the sensing length is limited to 100-200 mm long and uniform heating profile cannot be guaranteed. In our opinion, this paper demonstrates a fully distributed all-fiber hydrogen sensing solution with good prospects for practical applications.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Distributed hydrogen sensing using in-fiber Rayleigh scattering

Wang

Applied Physics Letters

et al. 2012

This letter reports a fully distributed hydrogen sensing technique using Rayleigh backscattering in palladium (Pd) and copper (Cu) coated optical fiber. The local in-fiber strain changes due to Pd hydrogen absorptions are interrogated spatially resolved optical frequency domain reflectrometry measurements of the Rayleigh signals. Electrical power is used to induce heating in the Pd coating, which accelerates both the hydrogen response and the sensor recycling. This technique promises an inexpensive and truly distributed fiber solution for continuous hydrogen leak detection with centimeter spatial resolution at room and low temperatures.