Publications internationales
Résumé: A kind of magnetic field sensor with enhanced sensitivity was designed by integrating the fiber Bragg gratings (FBGs) with the curved terbium-dysprosium-iron alloy (Terfenol-D) rods. Seven magnetic field sensors with Terfenol-D rods of different curvatures were fabricated and tested. The highest enhancement in magnetic field sensitivity is observed for sensors equipped with Terfenol-D rods having a curvature of 50 m−1. In addition, the designed sensor demonstrated directional sensitivity to the magnetic field, which was obtained to be 3.5 pm/◦ at 10 mT. The utilization of magnetostrictive materials in unconventional shapes (magnetostrictive rods in curved shapes) in this study not only enhances magnetic field sensitivity but also opens up a world of possibilities for future specific applications.
Résumé: This study presents a magnetic field temperature-refractive index sensor based on surface plasmon resonance (SPR) and photonic crystal fiber (PCF). The sensor integrates three independent sensing channels, offering high sensitivity with minimal cross-interference. By utilizing silver and gold in the form of thin films and nanowires, the sensor can simultaneously and accurately measure the external magnetic field, ambient temperature, and refractive index of the analyte. The influence of structural parameters on the sensor performance was analyzed using the finite element method (FEM), with subsequent optimization of these parameters. The sensor’s temperature sensing range ....
Résumé: A high-sensitivity triple-parameter sensor based on surface plasmon resonance (SPR) in a D-type photonic crystal fiber (PCF) is proposed. The sensor incorporates a Y-shaped sensing channel that enables the simultaneous and independent detection of three parameters with high sensitivity and minimal cross-interference.
Résumé: Magnetization investigations have been performed on single crystal of the substituted terbium-yttrium iron garnet, Tb1.98Y1.02Fe5O12 in strong dc magnetic fields up to 200 kOe applied along the easy 〈1 1 1〉, the intermediate 〈1 1 0〉, and the hard 〈1 0 0〉 axes of magnetization. When the internal magnetic field H is applied along the two difficult directions 〈1 1 0〉 and 〈1 0 0〉, different field-induced phase transitions between the associated collinear and the so-called canted magnetic phases are observed in the isothermal magnetizations MT(H)...
Résumé: In this letter, we report anomalous magnetic properties in high dc magnetic fields H up to 11 and 16 T from 1.35 up to 20 K on PrBa2Cu3O6.95 (PrBCO6.95) cuprate ceramic. Significant magnetic-field effects are revealed in the derivative of the magnetization M(T) versus T using two sets of values of H selected in the range of 2.5–9.5 T. Anomalies are observed at the low-critical point Tcr = 4–5 K, in the region of the spin reorientation phase transition temperature T2 = 10.5 K, and around the Néel temperature of the antiferromagnetic ordering of the Pr 3+ sublattice TN = 14 K. Using Arrott plot analysis, we identified weak field-induced phase transitions at two critical fields, Hcr1(T) ∼ 3.3 T and Hcr2(T) ∼ 7.5 T, whose associated transition lines exhibit an almost temperature-independent behavior in the range 1.35 K- T2, and seem to vanish in the vicinity of TN....
Résumé: A kind of dual-parameter fiber sensor based on the Terfenol-D rod combined with the cascaded Fabry-Péerot interferometer-fiber Bragg grating (FPI-FBG) structure is demonstrated, which integrates the FBG with the Fabry-Pérot cavity made by fiber and polydimethylsiloxane (PDMS). The problem of temperature cross-sensitivity in magnetic field measurement is simply and ingeniously avoided. The experimental results show that the sensing system’s temperature and magnetic field sensitivities are 121.56 pm/◦C and 21.6 pm/mT, respectively. By using the dual-parameter matrix, the resolutions of temperature and magnetic field measurement are obtained to be 1.003 ◦C and 0.069 mT, respectively.
Résumé: This work proposes and investigates a bent multimode-nocore-multimode optical fiber structure for vector magnetic field sensing applications. The bent no-core fiber (NCF) serves as the sensing area, and the gold film is deposited on its surface to excite the surface plasmon resonance effect. Due to the strong evanescent field ...
Résumé: A novel, to the best of our knowledge, vector magnetic field sensor with temperature compensation is proposed and investigated. The proposed sensor is realized by side polishing a multi-mode optical fiber and adopting the surface plasmon resonance (SPR) effect. The side-polished surface is coated with a magnetic fluid (MF) and polydimethylsiloxane (PDMS) successively along the fiber axis. The as-fabricated sensor can be used not only for magnetic field strength and direction sensing, but also for temperature detection. etc...
Publications nationales
Résumé: This work focused on the preparation of a surfactant magnetic liquid surfactant, which maghemite particles are obtained by chemical synthesis. The step of the co precipitation is required for the global efficiency of the synthesis and allows the control of the size of magnetic grains. The system has a polydispersity in size. Synthesized particles have a diameter about 8 nm (magnetic monodomaines). When submitted to the magnetic field, the ferrofluid surfact is described by a magnetization curve of Langevin type. Keywords: Magnetic liquid, Nanoparticles, Langevin law, Magnetic field, Colloidal solution.
Chapitres de livres
Communications internationales
Résumé: Influence of wavelength and magnetic nanoparticle concentration is demonstrated in magnetic photonic crystal fiber of terbium gallium garnet filled with magnetic fluids. The Faraday rotation reaches the largest value of 10731.85°/cm at a concentration of 0.25% and wavelength of 1.25 µm, whereas a reduced modal birefringence of 38.98 × 10–4 is attained.
Résumé: A novel design and model of a magneto-optical photonic crystal modulator is proposed and demonstrated, using the mode conversion by external magnetic field for phase modulation in the Mach-Zehnder Interferometer. Efficient modulation is numerically demonstrated with the 3D FDTD and BPM methods.