Analog of dual ultra-broadband and polarization-independent electromagnetically induced transparency metamaterial

An electromagnetically induced transparency analog (EIT-analog) metamaterial is numerically and experimentally demonstrated. The unit cell of the proposed structure is composed of two obliquely crossed cut wires (TOCCWs) and four rectangular split ring resonators (FRSRRs). Under the normal incidence of electromagnetic waves, TOCCWs and FRSRRs exhibit dipole, quadrupole, and hexapole resonances, which leads to the dual ultra-broadband and polarization-independent EIT-analog behavior. The coupling mechanism of the EIT effect is studied by analyzing transmission response and field distributions. In addition, the EIT-like transparency can be utilized for multi-channel and high-performance refractive index sensing applications.