Terahertz-band Multi-resonant Research And Design Of Metamaterial Devices

Terahertz waves (THz radiation, T-Ray, sub-millimeter wave, far-infrared ray) refer to the electromagnetic radiation with the frequency range of 0.1 THz to lOTHz (wavelength range of 3mm to 30μm, wave number 3.3cm-1 to 333cm-1); corresponding energy range is between 0.04kJ/mol and 4kJ/mol. Although terahertz wave has many unique strong points and the sources and detectors has been improved greatly, it has to develop many kinds of passive devices (e.g. terahertz filters, modulators, switches, etc) before it's used widely. There is a research area that develops quickly in recent years, namely Metamaterial, gives a brand-new idea to realize those devices.So far, researchers all over the world have studied Metamaterial working in microwave band thoroughly, due to the simplicity of development and measurement. Recently, one began to investigate Metamaterial working in terahertz band out of the reasons that it's urgent for developing THz science and THz experiment technology has been improved greatly. Nowadays, researchers have developed some devices such as one resonant THz switches and modulators, but it's still moving on. Especially, terahertz multi-resonant Metamaterial first brought forward in 2004 accelerates the development of THz science and technology.The research of THz multi-resonant Metamaterial both reinforce one's idea about Metamaterial and make indispensable preparation for terahertz multi-resonant filters, modulators, switches, etc.The following results have been achieved in this thesis:1. The electromagnetic characteristics of a basic symmetric dual-resonant Metamaterial unit are studied thoroughly based on equivalent circuit theory method. Grounded on that, the relationship between structure parameters and resonant characteristics of Metamaterial is found.2. Given great efforts, four kinds of planar terahertz electric-response multi-resonant Metamaterial structures, namely symmetric dual-resonant Metamaterial (SDM), asymmetric dual-resonant Metamaterial (ADM), symmetric triple-resonant Metamaterial (STM) and asymmetric triple-resonant Metamaterial (ATM), have been designed and optimized.3. Based on the design and analysis of dual-resonant and triple-resonant Metamaterial structures, a planar terahertz electric-response fourfold Metamaterial structure that has four resonant points in transmission curve has been designed and optimized. Besides, the electromagnetic characteristics of a dual-resonant complimentary Metamaterial structure were analyzed.4. Techniques and procedures of making terahertz multi-resonant Metamaterial samples are explored experimentally. Problems and corresponding solutions of making Metamaterial samples were analyzed too. Grounded on that, four kinds of planar terahertz electric-response multi-resonant Metamaterial structures, namely symmetric dual-resonant Metamaterial (SDM), asymmetric dual-resonant Metamaterial (ADM), symmetric triple-resonant Metamaterial (STM) and asymmetric triple-resonant Metamaterial (ATM), have been made successfully.5. The four kinds of processed Metamaterial samples were measured by THz-TDS system in the terahertz research center of UESTC. The results show good agreement of transmission characteristics between simulated Metamaterial structures and manufactured Metamaterial structures, which proved the feasibility and reliability of the techniques and parameters.