Electromagnetically induced transparency-like optical responses in all-dielectric metamaterials

We investigate numerically the electromagnetically induced transparency-like behavior in all-dielectric planar photonic metamaterials. The proposed metamaterial consists of a periodical array of silicon metamolecules. Each metamolecule comprises a radiative resonator and a subradiant resonator that couple to each other through near field interactions. Resonances with extremely high quality factors of up to several thousands are predicted, and a group refractive index of more than 200 can be realized at the transparency window. This provides an effective platform for slow light, enhanced nonlinearity and sensing applications and presents opportunities for developing new types of active lasing and optomechanical metamaterials.