Design of a Gold-Nanowires Embedded PCF for Magnetic Field and Temperature Sensing

Abstract

A photonic crystal fiber (PCF) sensor comprising two sensing channels for magnetic field and temperature measurements is proposed. In order to detect the magnetic field and temperature effectively, the two sensing channels of the proposed sensor are embedded with gold nanowires and filled with Polydimethylsiloxane (PDMS) and magnetic fluid (MF), respectively. Additionally, this configuration simplifies the fabrication process and eliminates some problems when plasmonic material is deposited in the inner or outer surface of PCF. The performance of the proposed sensor is numerically investigated by the finite element method (FEM). The optimal structural parameters have been determined by analyzing the loss curves and energy of the y-polarized core mode ultimately. Furthermore, the sensitivity is not particularly sensitive to the sizes of the cladding air holes, indicating the sensor has better manufacturing tolerance. The simulation results reveal the maximum magnetic field sensitivity is 238.4 pm/Oe at the magnetic field of 30–300 Oe, and temperature sensitivity is − 1103.6 pm/°C at the temperature of − 20–40 °C. The proposed sensor can detect sub-zero temperatures with a high magnetic field sensitivity. Given its low fabrication complexity and extensive detection range, this PCF-SPR sensor has potential applications in magnetic environments at low temperatures, such as geological exploration, marine environment monitoring, and so on.