The terahertz metamaterial absorber sensor is an important functional device of the metamaterials. It can realize not only the perfect absorption in the incident terahertz wave, but also the detect sample by monitoring the deviation of the absorption frequency of the metamaterial absorber sensor.

Dual-band metamaterial absorber sensor has double frequency resonance peak. By matching the characteristic frequency between the sensor and the substance to be measured, the information reflecting the difference of the substance to be measured is increased, to improve the accuracy and sensitivity of material detection. Compared with the traditional metamaterial absorber sensor, the dual-band metamaterial absorber sensor can realize very accurate sensing and detection function through multi-point matching of information.

In this paper, a double band terahertz band metamaterial absorber sensor is proposed. The absorption rate of the metamaterial absorber sensor reaches over 99% at 0.387 THz and 0.694 THz frequency point, achieving “perfect absorption”. Through the analysis of a series of materials with different refractive indices to be measured, the suitable sensing range of the designed terahertz metamaterial absorber sensor is obtained. By analyzing the different thickness of the substance to be measured and the different medium layer materials, the thickness of the substance to be measured and the medium layer materials which can improve the sensing performance of the sensor are obtained. In this paper, the sensing identification of edible oil is taken for example to verify that the dual-band terahertz metamaterial absorber sensor designed in this paper can realize high sensitivity and rapid detection, and has a broad development prospect in the field of sensing and detection.