A new one-dimensional photonic crystal magnetic sensor based on magnetic fluid film with excellent sensing ability and figure of merit

• Published in: Journal of magnetism and magnetic materials 2022-03, Vol.545, p.168753, Article 168753
• Main Authors: Ge, Daohan, Chen, Hui, Hu, Zhou, Shi, Jiakang, Zhang, Liqiang
• Format: Article
• Language: English
• Subjects: 1D photonic crystal; Crystal structure; Figure of merit; Fluid films; FOM; Interrogation; Magnetic fields; Magnetic fluid film; Magnetic fluids; Magnetic sensor; Parameter sensitivity; Photonic crystals; Refractivity; Sensors; Transmission loss
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2021.168753

•1D photonic crystal magnetic sensor.•Magnetic fluid film.•Excellent sensing ability.•Reflection spectrum has a linear relationship with the magnetic field. A magnetic sensor based on a one-dimensional (1D) photonic crystal was proposed. The transmission characteristics of the 1D photonic crystal magnetic sensor were analyzed using the theory of rigorous coupled wave analysis (RCWA). The variation pattern of magnetic fluid films refractive index with magnetic field and the effect of structural parameters on sensitivity and figure of merit (FOM) were investigated. Based on the wavelength interrogation method, the resonance wavelength is red-shifted with the change of the magnetic field for certain structural parameters. The results show that the structure has a highly linear response within the external magnetic field variation range from 30 Oe to 90 Oe, and its sensitivity and FOM can reach 0.817 nm/Oe and 17.439 Oe−1. Due to the advantages of 1D photonic crystal structure has harp peak, highly linear response, and low transmission loss. The structure has a large potential for applications in complex environments and real-time monitoring.