Details

Autor(en) / Beteiligte

• Liu, Qiang
• Li, Shu-Guang
• Wang, Xinyu

Titel

Sensing characteristics of a MF-filled photonic crystal fiber Sagnac interferometer for magnetic field detecting

Ist Teil von

• Sensors and actuators. B, Chemical, 2017-04, Vol.242, p.949-955

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •The magnetic field sensitivity at the wavelength of 1.79μm is −8900pm/Oe.•The sensitivity increases infinitely near the special wavelength related with zero-point group birefringence Bg.•The sensitivities are 384pm/Oe (51,569nm/RIU), −430pm/Oe (−57,747nm/RIU) for the detected magnetic field range 410–600Oe and they are 530pm/Oe (66,596nm/RIU) and −580pm/Oe (−72,879nm/RIU) for 100–250Oe. A highly sensitive magnetic field sensor based on Sagnac interferometer consisted of a polarization maintaining photonic crystal fiber (PCF) filled with magnetic fluid (MF) is proposed and demonstrated. The refractive index of MF is sensitive to magnetic field H and the fiber Sagnac interferometer is sensitive to refractive index, so the sensing structure of our magnetic field sensor is designed. The water-based nanoparticles Fe3O4 is used which possesses low refractive index. The refractive index of MF follows the Langevin function and changes linearly with magnetic field H in our considerable magnetic field region. The parameters of λ, B(λ, H) on the influences of sensitivity are analyzed. We find a new phenomenon the two dip wavelengths shift in the opposite direction as magnetic field increases. The phenomenon is explained by group birefringence Bg which decreases and its sign changes as magnetic field increases. The sensitivity increases infinitely near the special wavelength related with zero-point Bg. The average sensitivities are 384pm/Oe (51,569nm/RIU), −430pm/Oe (−57,747nm/RIU) which turn out pretty well and the R-squares are 0.98113, 0.98415 respectively for the detected range 410–600Oe.