Sensing and frequency selecting with toroidal resonance in metasurface

A double M-shaped metasurface is proposed and produced to realize a high Q-factor resonance at 13 GHz. The numerical and experimental results show that the high Q excitation of the structure is caused by the strong toroidal dipole. The novel toroidal metasurface can be a refractive index sensor with a high sensitivity of 3.2 GHzRIU −1 . In addition, the double layer metasurface can achieve frequency selection with a bandwidth of 0.27 GHz. The proposed metasurface further extends the application of toroidal dipole in the field of sensing, frequency selective surface and so on.