Fig. 5From: Design of Quad-Band Terahertz Metamaterial Absorber Using a Perforated Rectangular Resonator for Sensing Applicationsa shows the dependence of the absorption performance of the quad-band light absorber on the change of the refractive index (n) of surroundings. b 1 and b 2 are respectively the resonance frequencies of the modes C and D as the function of the refractive index nBack to article page