Abstract:The tunable refractive index of the magnetic fluid is a unique optical property,which has attracted a lot of research interest in the magnetic field sensing in recent years.Based on this property,the magnetic fluid is introduced into the one-dimensional photonic crystal as the defective layer to realize the magnetic field sensing.Because of the defect,the defect peak appears in the transmission spectra of the defective photonic crystal.According to sensitivity of the refractive index in the magnetic field,the defect peak of photonic crystal varies when the magnetic changes,so the magnetic can be measured by the wavelength shift value of the defect peak.Using the transfer matrix method,the defect peak is simulated with the change of the applied magnetic field under different structural parameters.This provides a theoretical basis for the practical application of defective one-dimensional photonic crystal sensor in magnetic measurement.