This paper designs a terahertz metamaterial sensor based on a three-metal strip structure, which can generate a fourth-order resonance with a high quality factor. Different from the traditional method of manually adjusting structural parameters to obtain the maximum quality factor, this paper utilizes the quantum-behaved particle swarm optimization (QPSO) to optimize structural parameters of the metamaterial sensor, significantly enhancing the efficiency of the optimization process. The maximum quality factor of the fourth-order resonance optimized by QPSO is as high as 58, while the peak height is greater than 0.8. When an analyte layer with a thickness of 20 μm is covered onto the sensor surface, the sensing sensitivity reaches 198 GHz/RIU. The sensor can be used in high-sensitivity detection, trace biological sample detection and other fields.

High quality factor, metamaterial sensor, quantum-behaved particle swarm optimization, terahertz