利用二氧化钒薄膜绝缘相—金属相的相变特性,提出了一种基于超材料的温控太赫兹调制器,研究了相变超材料在太赫兹波段的传输特性和温控可调谐特性.当入射太赫兹波为水平偏振或垂直偏振状态时,器件的透过率谱线在1THz附近呈现出两个独立的、中心频率分别为1.3THz和1.7THz、带宽分别为0.2THz和0.35THz的透射宽带.当温度从40C至80C变化时,两宽带的透过率发生明显的降低,在二氧化钒的相变温度(68C)时尤其灵敏,对入射光的二种偏振状态,调制深度均达到60%以上,实现了良好的调制效果.
Utilizing insulator-metal phase transition of vanadium dioxide thin film, we propose a thermally controlled terahertz modulator based on metamaterial, and research the transmission characteristics and temperature tunable characteristics of phase transition in metamaterials in THz wave band. While the incident THz wave is of horizontal polarization or vertical polarization, two independent pass bands are generated near 1 THz. The center frequencies of the two pass bands are 1.3 THz and 1.7 THz, the bandwidths of them are 0.2 THz and 0.35 THz. In addition, when temperature rises from 40 ℃ to 80 ℃, the transmissions of the two pass bands drop apparently, especially at phase transition temperature of 68℃. For the two polarization states, the modulation depths achieve 60% or more, which is the great function of a modulator.