Design of photonic crystal fiber to excite surface plasmon resonance for highly sensitive magnetic field sensing

Abstract

To improve the sensing performance of optical fiber magnetic field sensor based on magneto-refractive effect, a D-shaped photonic crystal fiber-surface plasmon resonance (PCF-SPR) sensor based on magneto-refractive effect is proposed and its magnetic field sensing characteristics are investigated. The designed D-shaped PCF has a core-analyte-gold structure. Within the D-shaped PCF, the side polishing surface is coated with the gold film and the special hole is sandwiched between the core and the gold film. To realize the high magnetic field sensitivity for the fiber SPR magnetic field sensor, the special hole is filled with magnetic fluid (MF). In this paper, we analyze the mode transmission characteristics and magnetic field sensing characteristics of this fiber sensor by finite element method. We also obtain a general rule for the optimization of PCF-SPR sensors by analyzing the dispersion curves, the energy of the surface plasmon polariton mode and the core mode on the sensing performance of the designed fiber sensor. The maximum refractive index sensitivity and magnetic field sensitivity of the optimized fiber are 59714.3 nm/RIU and 21750 pm/mT (50-130 Oe), respectively. Compared with optical fiber magnetic field sensors based on magneto-refractive effect reported previously, the magnetic field sensitivity in this paper is nearly two orders of magnitude higher and it can initially achieve nT magnitude magnetic field resolution and testing capability. The proposed fiber sensor has the advantages of simple structure, easy production, high sensitivity, and strong environmental adaptability. It not only improves the sensing performance of optical fiber magnetic field sensors, but also provides an ideal alternative platform for biosensors like microfluidics because of its high refractive index sensitivity and the special structure.

Research Progress on Magneto-Refractive Magnetic Field Fiber Sensors

“…Besides large-mode field fibers, exploiting a side-polished fiber with Evanescent Field leakage is also feasible. Wang et al [ 65 ] proposed a sensor with Au films deposited on the side-polished surface, which has an ultrahigh sensitivity of 2175 pm/Oe and a good resolution accuracy of 46 nT (1 nT = 10 −9 T). Moreover, sensors based on the side-polished fiber have a good vector property owing to an asymmetric structure.…”

High sensitivity and wide detection range temperature and refractive index photonic crystal fiber sensor

“…In recent years, many PCF-SPR sensors, including refractive index (RI) [5,6], temperature [7,8], and magnetic field [9,10], have been reported. Peng et al proved the coupling * Author to whom any correspondence should be addressed.…”

A high magnetic field sensitivity PCF‐SPR sensor working in the near‐infrared wavelength band

“…1 Electromagnetic field and temperature sensors have undergone extensive research and application. 2,3 However, these sensors exhibit certain drawbacks, such as large dimensions, exorbitant cost, inadequate environmental adaptability, necessitating supplementary temperature control systems, 4 and limited dynamic range of testing. [5][6][7] New application requirements for magnetic field and temperature sensors, encompassing heightened sensitivity, integration, cost-effectiveness, and miniaturization, have emerged alongside developments in ground vehicle detection, unexploded ordnance detection, unmanned aerial vehicles, and other fields.…”

“…Magnetic field and temperature are fundamental parameters in diverse fields, including power grid monitoring, location navigation, earthquake early warning, and medical diagnosis 1 . Electromagnetic field and temperature sensors have undergone extensive research and application 2,3 . However, these sensors exhibit certain drawbacks, such as large dimensions, exorbitant cost, inadequate environmental adaptability, necessitating supplementary temperature control systems, 4 and limited dynamic range of testing 5–7 …”