Temperature Insensitive Magnetic Field Sensor Based on Ferrofluid Clad Microfiber Resonator

In this letter, an inherently temperature insensitive magnetic field sensor based on microfiber knot resonator with ferrofluid as cladding was theoretically and experimentally demonstrated. It was theoretically shown that the thermal property of the proposed sensor could be effectively suppressed by selecting the optimal microfiber diameter. On the basis of that, a sensor with its microfiber diameter of 2.92 μm was experimentally fabricated and its temperature sensitivity was demonstrated to be as low as 0.17 pm/°C with the temperature ranging from 20 °C to 80 °C. The results take a step forward toward the development of thermal stable devices based on the microfiber resonators.