Photonic crystal fiber injected with Fe3O4 nanofluid for magnetic field detection

We report a magnetic field sensor having advantages of both photonic crystal fiber and optofluidics, combining them on a single platform by infiltrating small amount of Fe3O4 magnetic optofluid/nanofluid in cladding holes of polarization-maintaining photonic crystal fiber. We demonstrated that magnetic field of few mT can be easily and very well detected with higher sensitivity of 242 pm/mT. The change in the birefringence values has been correlated to the response of nanofluid to applied field.