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Author

Xiangnan Wu

Bio: Xiangnan Wu is an academic researcher from Xi'an Jiaotong University. The author has contributed to research in topics: Fabry–Pérot interferometer & Fiber Bragg grating. The author has an hindex of 3, co-authored 4 publications receiving 38 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, a mixed-gas sensing system utilizing a fiber Fabry-Perot (FFP) filter and fiber Bragg Gratings (FBG) was developed by modulating the transmission wavelength of FFP within the width of one absorption line of the target gas.
Abstract: A practical mixed-gas sensing system utilizing a fiber Fabry–Perot (FFP) filter and Fiber Bragg Gratings (FBG) was developed. By modulating the transmission wavelength of FFP within the width of one absorption line of the target gas, the system can detect different kinds of gaseous species selectively. A FBG with center wavelength being aligned to the absorption peak of the target gas was employed as wavelength reference to make the transmission wavelength of FFP modulate stably in a required region. The properties of the proposed system were demonstrated experimentally by simultaneous detection of acetylene (C 2 H 2 ) and carbon monoxide (CO). Approximate linear relationships between the system responses and the input gas concentrations were demonstrated by experiments. The minimum detectable C 2 H 2 and CO concentration of ∼15 ppm and ∼300 ppm were also achieved by experiments respectively.

29 citations

Journal Article
TL;DR: A method of modeling the wavelength-voltage relationship of FPF online in each FPF scanning cycle was proposed and the structure of the system is compact and the proposed modeling approach has important meaning in FBG sensors system when FPF is used as wavelength demodulator.
Abstract: In order to improve the measurement accuracy of FBG sensing system, particle swarm optimization (PSO) algorithm combined with reference FBGs array was applied to investigate the nonlinearity and hysteresis character of Fabry-Parot filter (FPF). A method of modeling the wavelength-voltage relationship of FPF online in each FPF scanning cycle was proposed in the present paper. The feature of particle swarm optimization algorithm such as fast convergence and simple implementation makes the process of modeling wavelength-voltage relationship of FPF be completed with low computing cost and high accuracy. With the set-up model, the absolute error in wavelength detection of FBG sensors was demonstrated by experiments to be as low as 0.03 nm. The structure of the system is compact and the proposed modeling approach has important meaning in FBG sensors system when FPF is used as wavelength demodulator.

7 citations

Journal ArticleDOI
TL;DR: In this article, the nonlinearity of a piezo-electrical transducer driven fiber Fabry-Perot filter (FFP) is investigated and calibrated using a group of fiber Bragg gratings (FBGs).

4 citations

Proceedings ArticleDOI
03 Dec 2008
TL;DR: In this paper, a tunable optical filter (TOF) based acetylene sensing system is proposed, which modifies the wavelength of TOF within the width of one absorption line of acetylene.
Abstract: A tunable optical filter (TOF) based acetylene sensing system is proposed in this paper. By modulating the wavelength of TOF within the width of one absorption line of acetylene, both the sensitivity and selective sensing properties of the system for sensing acetylene have been much improved. Approximate linear calibration curves in sensing acetylene is obtained by experiments. The minimum detectable acetylene concentration of 5ppm is also achieved by experiments. The proposed system has great potential in developing mixed-gas sensing system.

Cited by
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Journal ArticleDOI
TL;DR: In this article, a high sensitive multi-component gas sensing system was proposed, in which the slotted photonic crystal waveguide (SPCW) was used as the gas cell and the fiber Fabry-Perot (FFP) was adopted as the wavelength filter by choosing the refractive index that infiltrated in the first and second rows of air holes adjacent to the slot respectively.
Abstract: A high sensitive multi-component gas sensing system was proposed, in which the slotted photonic crystal waveguide (SPCW) was used as the gas cell and the fiber Fabry–Perot (FFP) was adopted as the wavelength filter By choosing the refractive index that infiltrated in the first and second rows of air holes adjacent to the slot respectively, the working wavelength of SPCW could be tuned to matches with one absorption line of the measured gas, thus, the system could detect different kinds of gases selectively Meanwhile, a very high group index of 150 with flat bandwidth could be achieved and the electric field enhancement factor would reach to 12 Combined with the wavelength modulation techniques (WMS) for signal processing, the minimum detection limit of 156 ppm was achieved

36 citations

Journal ArticleDOI
TL;DR: In this article, a support vector regression based on binary particle swarm optimization algorithm (BPSO-SVR) was proposed to predict nitrogen content of rice in different growth stages using rice canopy's hyperspectral reflectance toward the development of precision nitrogen status monitoring.

31 citations

Journal ArticleDOI
TL;DR: In this article, a miniature and sensitivity gas sensor based on slotted photonic crystal waveguide (SPCW) was presented, in which the correlation spectroscopy method was applied for signal processing and the SPCW was used for the gas cell.
Abstract: A miniature and sensitivity gas sensor based on slotted photonic crystal waveguide (SPCW) was presented, in which the correlation spectroscopy method was applied for signal processing and the SPCW was used for the gas cell. To enhance the system sensitivity, the structure of the SPCW was optimized to possess extremely high group index and very large light confinement in the slot. Simulation results indicated that the measuring resolution of acetylene gas of 1 ppm was achieved with good temperature stability. Additionally, the active region was only 1 mm long, which could be of great advantage in the use of the limited space.

23 citations

Journal ArticleDOI
01 Jul 2018-Optik
TL;DR: A novel demodulation algorithm of particle swarm optimization based simulated annealing (PSO-SA) for multiplexing fiber Bragg grating (FBG) sensor networks is reported and it is theoretically prove that multiple FBGs can be demodulated in a 2, 3 and 4-grating-network respectively even though the grating spectra are fully or partially overlapped.

23 citations

Journal ArticleDOI
TL;DR: In this article, an optimized strain-demodulation method based on piezo-electrical transducer (PZT) driven fiber Fabry-Perot (FFP) filter is proposed and experimentally demonstrated.

19 citations