【作者】 王昌雷；

【导师】 邢岐荣；

【作者基本信息】 天津大学 ， 光电子技术， 2010， 博士

【摘要】 随着太赫兹科学的发展,太赫兹技术逐渐在频谱,成像,国防以及通信领域的显现出广阔的应用前景。越来越多的领域开始重视起这门新兴的学科。由于太赫兹科学起步较晚,对太赫兹波的有效操控是当前技术的盲点,也是太赫兹研究的热点。本论文主要从四个方面研究了对太赫兹波幅度和频谱的操控:一.利用太赫兹时域频谱技术(THz-TDS)研究了氧化钒(VOx)薄膜的半导体-金属相变特性,尤其是硅基VOx薄膜的光致半导体-金属相变特性。分析了不同波长的连续光照射、飞秒脉冲激光照射等不同光激发方式下的硅基VOx薄膜对太赫兹波的光调制特性。二.通过数值模拟和实验研究了复合型表面等离基元极化波(SPP)结构的THz波滤波特性,采用唯象的分子模型理论对复合结构的透射频率随结构变化的现象进行了分析。并从理论和实验上对复合结构中蕴含的SPP模式间的耦合过程进行了验证,根据实验结果计算了SPP之间的耦合系数。三.结合硅基VOx薄膜的光调制特性和SPP结构的滤波特性,设计了VOx薄膜与金属孔阵列的复合结构,VOx薄膜与金属块阵列的复合结构,以及硅基VOx微结构阵列。并通过实验检测了这种双功能器件的特性。通过模拟设计了几种基于VOx薄膜和SPP结构的器件,同时具有调制和滤波功能,实现了频率可调的光控性能。四.把硅基VOx的光调制性质应用到THz-TDS中,作为太赫兹波的光控斩波器,取代传统的机械马达斩波器,成功测到了太赫兹脉冲的波形,并在理论上分析了该斩波器与传统马达斩波器的在测量太赫兹脉冲时差异形成的原因。更多还原

【Abstract】 As the development of the terahertz (THz) science,the fascinating application potentials in spectrum analysis,imaging,security,and communication are found more and more close to the human being’s life and THz science has been receiving more and more attention from kinds of fields . Since the research on THz science is more lagging than other frequency regions,such like microwave and visible range,effective manipulation methods on THz waves are extremely limited and that is also the reason why so many people pay so hard word on it. In this thesis,four parts are included as followed about THz manipulation to the amplitude as well as the spectra.First , the semiconductor-metal phase transition properties of vanadium oxide(VOx),especially the photo-induced phase transition,are studied by using terahertz time domain spectroscopy (THz-TDS). The optical response of silicon based VOx film under different illuminating way,i.e. CW laser with various wavelengths and femtosecond laser pulses.Second,the filtering performances of hybrid surface plasmon polarition structures are examined by both numerical simulations and experimental measurements. The geometrical dependence of transmission frequency shift is analyzed by using phenomenological molecule model. The coupling between different-typed SPPs modes are studied by theoretical analysis and experiment results and the coupling coefficient is calculated.Third,combined the optical modulation feature of silicon-based VOx films and the filtering effect of SPP structures,composite structures like VOx film on metal hole array and VOx film on metal patch array were designed and so was the microstructured VOx film. The experimental measurements show obvious both filtering and modulating function in such devices, and optical frequency tunability is realized .Last,by using its modulation effect to THz waves,the silicon-based VOx film was employed as an optically controlled THz chopper,a necessary element of THz-TDS,and THz pulses are succeded to be measured instead of traditional mechanical motor chopper. The origin of the difference between THz waveform measurements based on such optical chopper and normal mechanical chopper is analyzed.更多还原