Double electromagnetically induced transparency resonance in slotted metasurfaces supporting bound states in the continuum

This work proposes and theoretically demonstrates a double electromagnetic induced transparency resonance generated by a novel dielectric metasurface consisting of a periodic array of square slots. The resonances stem from symmetry-protected bound states in the continuum whose quality factor tends to infinity when the structure is symmetric. The quasi-bound states in the continuum supported by the asymmetric metasurface can be exploited to obtain double high quality factor resonances in transmission (electromagnetic induced transparency like effect) that can be modulated with the external refractive index for sensing.