Abstract
In order to improve the integration of fiber optic sensors, this paper designs a dual-core three-channel photonic crystal fiber(PCF)optic sensor that can simultaneously measure the refractive index of a liquid, its temperature, and the ambient magnetic field. Based on the PCF as well as SPR principles, the sensor has two D-planes, one coated with PDMS as well as a gold film for detecting temperature and the other coated with a gold film for detecting refractive index and coated with a gold film over the air holes on the side of the core where the refractive index is measured, and a magnetic fluid injected into the air holes to detect the magnetic field. The results show a maximum sensitivity of 20,000 nm/RIU for refractive index, a linear sensitivity of 116 pm/Oe for magnetic field, and 5,300 pm/°C for temperature when the sample's refractive index is between 1.36 and 1.42, the temperature is between 0°C and 50°C, and the magnetic field is between 20 Oe and 550 Oe. The sensitivity matrix of temperature versus refractive index is also given. The sensor is compact and simple to prepare, providing a new solution for miniaturization and integration of multifunctional photonic devices.