High sensitivity magnetic field sensing method based on magneto-photonic crystal slow light Sagnac interferometers

摘要

The magnetic field sensing properties based on the slow light effect of magneto-photonic crystals are studied. The nonreciprocal slow light effect of the magneto-photonic crystal immersed into an applied magnetic field is deduced by the scattering matrix method. A Sagnac interferometer is designed to enhance the sensitivity coefficient to the magnetic field and suppress the influences of reciprocal disturbances. Numerical results show that the sensitivity coefficient of a MPC slow light sensor is about 50 times that of the sensor made of bulk magneto-optic material with the same thickness. The influences of structural parameters of the magneto-photonic crystal, such as the number of periods, the duty ratio and the chirp, on the sensitivity coefficient are discussed. (C) 2015 Elsevier GmbH. All rights reserved.