Tunable enhanced sensing of ferrite film using meander-shaped spoof surface plasmon polariton waveguide

In this letter, the magnetic field enhancement characteristics of the spoof surface plasmon polaritons (SSPPs) is utilized to enhance the sensing of thin ferrite film. The operating sensing frequency can be tuned by adjusting the bias static magnetic field. For demonstration, a magnetic yttrium iron garnet film (i.e., YIG) with small thickness of 2 μ m over a simple SSPP-based sensing structure is designed, fabricated and measured, showing improvement of higher than 20 dB to the absorption (i.e., sensing ability). The proposed method has significant potentials in the application of plasmonic integrated devices using thin ferrite materials.