Electromagnetically induced transparent terahertz dual-split-ring metamaterial for ultra-high sensitivity sensor applications

We present three dual-split-ring metamaterial (DSRM) devices with electromagnetic induced transparency (EIT) characteristics and simulated the optical parameters of the device. They are composed of outer split-ring resonators (SRRs) with different rotation angles of 0°, 45°, and 90°, named as DSRM-1, DSRM-2, and DSRM-3 respectively. By changing the height of the outer SRR from 0.5 μm to 4.0 μm, the EIT resonances of DSRM devices can be modulated. The EIT windows of DRSM-1 and DSRM-2 can be tuned 0.4 THz and 0.3 THz, respectively. Meanwhile, both DSRM-1 and DSRM-2 are ultra-highly sensitive to the change of ambient refractive index. The maximum sensitivity is 638 GHz/RIU. Moreover, DSRM-3 shows stable to the change of background refractive index. The EIT resonant intensity of DSRM-3 can be modulated gradually by increasing the height of the outer SRR. These results indicate that DSRM devices possess potential applications in the reconfigurable filters, optical switches, programmable logic operators, highly sensitive sensors in the THz-wave optoeelctronics fields.