Ampere force based photonic crystal fiber magnetic field sensor

We fabricate an Ampere force based photonic crystal fiber (PCF) magnetic field sensor by bonding a PCF in-line modal interferometer (PCFMI) with an aluminum (Al) wire together. This sensor is very compact, cost-effective, temperature insensitive, highly stable over time and easy to be fabricated only including cleaving and splicing processes. An electrical current flowing through the Al wire in a perpendicular magnetic field can generate Ampere force to lead to the curvature of the Al wire and the PCF. As the cladding mode of the PCF with a large mode field diameter is very sensitive to the curvature, the average magnetic field sensing sensitivity can reach 32.4 pm/mT when 100 mA electrical current is applied with excellent repeatability. Higher sensitivity and a minimal detectable magnetic field of less than 0.1 mT can be realized by increasing the applied electrical current.