Design And Research Of The THz Devices Based On Metamaterials

This thesis is based on the characteristics of metamaterials, mainly discusses three aspects: terahertz resonator design and development, terahertz filter design and research, and terahertz modulator design and research.In terms of the design and development of THz resonators, five works have been completed. Firstly, based on the SRR resonant structure, symmetric structure of single band metamaterial sample(SSM) was designed, simulated and measured results show that the structure has a strong resonance at 0.43 THz; Secondly, on the basis of the SSM, the symmetric structure of dual-band metamaterial sample(SDM) was proposed after adding the SRR coupling structure. Simulated and measured results show that it can produce two resonant frequencies near 0.29 THz and 0.66 THz; Thirdly, on the basis of the SSM, the symmetric structure of triple-band metamaterial sample(STM) was proposed after adding the metal strip. Simulated and measured results show that it can produce three resonant frequencies near 0.298 THz, 0.559 THz and 0.904 THz;Fourthly, we simulated the complementary structure of the above three structures, the results show that these complementary structures can realize the function of the transmission passband. Fifthly, processing and testing all resonator structures, experimental results and the simulation results are in good agreement.In the study of terahertz filter, three works have been completed. Firstly, using structure of the single band resonator, double and three metal layers of one stopband terahertz filters were designed, respectively. And the three layers of metal structure of the filter can perform one broad bandgap located at f0 ≈ 0.87 THz with the bandwidth 0.54 THz. Secondly, using the structure of the dual-band resonator, dual-stopbands terahertz filter with two layers of metal structure was designed. Center frequencies of the two stopbands are 0.67 THz and 1.19 THz, respectively, of which with the bandwidth 0.12 THz and 0.18 THz. Finally, we achieved the bandpass filter function with single pass band and double pass bands by using the complementary structures of the stop band filter structures.In the study of terahertz modulator, mainly based on the dual-band resonators and tri-bands resonator model structure, using laser illuminate semiconductor substrate located in the cracks of the metal structure and make the carrier concentration of the semiconductor change, so that causing changes in conductivity, thus realize the blue shift or red shift of the resonance frequency, but also the amplitude modulation, achieved the THz wave frequency modulation and amplitude modulation function. In addition, considering the realizability of experimental test, two types of modulators were designed.