In-line temperature-compensated vector magnetic field sensor with side-polished fiber

A novel, to the best of our knowledge, vector magnetic field sensor with temperature compensation is proposed and investigated. The proposed sensor is realized by side polishing a multi-mode optical fiber and adopting the surface plasmon resonance (SPR) effect. The side-polished surface is coated with a magnetic fluid (MF) and polydimethylsiloxane (PDMS) successively along the fiber axis. The as-fabricated sensor can be used not only for magnetic field strength and direction sensing, but also for temperature detection. The achieved magnetic field intensity sensitivities are 1720 pm/mT (90° direction) and −710 pm/mT (0° direction), and the temperature sensitivity is −2070 pm/°C. On top of its temperature compensation ability, the easy fabrication and very high sensitivity of the proposed sensor are attractive features for vector magnetic field sensing applications.