Optimized absorption performance of a terahertz single mode metamaterial for gas and liquid detection

Abstract. Metamaterial absorbers are widely used in the sensing field based on their rich resonance behaviors. So far, the applications of metamaterial absorbers in gas sensing have not been paid much attention by researchers. A single-mode narrow bandwidth THz metamaterial absorber is suggested and validated. An absorption peak is excited based on local surface polarization mode resonance and dielectric loss in the 2 to 36 THz band. In experiments, the hole array diameter R is increased, the absorption peak is increased from 0.51 to 0.66, and resonance position is moved to the high-frequency region. When the dielectric layer thickness h2 is increased, the absorption peak is increased from 0.51 to 0.57, and resonance position is moved to the low-frequency region. Similarly, when the dielectric layer thickness h3 is increased, the absorption peak is increased from 0.51 to 0.53, and resonance position is also moved to the low-frequency region. This metamaterial absorber exhibits the feasible for gas and liquid sensing.