频率可调谐的太赫兹波高速信号调制器研究

Faced with the growing contraditions between the gradual depletion of low-frequency spectrum resources and the surging demand in bandwidth in the field of wireless communication, research and development on the terahertz communication can provide a viable technology for high-capacity wireless transmission channels, and greatly alleviate the crowded problem of current frequency band. However, terahertz wave signal modulator becomes the current bottleneck of terahertz communication applications. In this project, the silver up-layer, the organic polymer layer, buffer layer, and the silver low-layer are orderly coated on the underside of high resistance silicon prism. The upper and lower silver layers are used as the electrode. When the electric field is applied in the electrode, the guided mode-resonance absorption peaks of the designed structure can be controlled due to electro-optic effect, so that the intensity of the reflected terahertz wave is modulated by the applied electric field. A high-speed signal modulation of the terahertz wave is achieved. According to the synchronous angle dependent on wavelength, changing incident angle of the terahertz wave, wide frequency modualtion and frequency tunning in terahertz region can be achieved. The project studies the use of both electronically controlled guided-mode resonance absorption and electro-optic effect to achieve high-speed signal modulation, frequency tunning mechanism and the establishment of the corresponding theoretical analysis model. The design optimization, production and testing of the terahertz wave modulator are accomplished. The significance of the project is that a compact terahertz modulator with high modulation speed, wide bandwidth, low operating voltage can be obtained, which will promote the application and development of terahertz wave communication.

面对低频频谱资源逐渐枯竭和无线通信对带宽需求激增矛盾的日益加剧，太赫兹频段通信的研究开发可为大容量的无线传输提供一个可行的技术途径，可以极大缓解目前频段拥挤的问题，然而太赫兹波信号调制器成为当前太赫兹通信应用瓶颈。本项目拟在高阻硅棱镜底面顺序制作上银膜层、有机聚合物层、缓冲层、下银膜层，上下银膜层作为电极，在电极上加电场利用电光效应控制该结构的导模共振吸收峰，这样反射的太赫兹波强度被施加于电极上的电场所调制，实现对太赫兹波高速信号调制。根据不同波长其同步角不一样的特性，改变太赫兹波入射角，可以实现频率可调谐，获得大的调制宽带。项目研究利用电控导模共振吸收和电光效应共同作用对太赫兹波进行高速信号调制和频率可调谐的机理，并建立相应理论分析模型；完成太赫兹波调制器结构优化设计、制作与测试。项目意义在于获得调制速度高，带宽大，工作电压低，结构紧凑的太赫兹波调制器，推动太赫兹通信技术应用与发展。

面对低频频谱资源逐渐枯竭和无线通信对带宽需求激增矛盾的日益加剧，太赫兹频段通信的研究开发可为大容量的无线传输提供一个可行的技术途径，可以极大缓解目前频段拥挤的问题，然而太赫兹波信号调制器成为当前太赫兹通信应用瓶颈。. 本项目在高阻硅棱镜底面顺序制作上银膜层、有机聚合物层、缓冲层、下银膜层，上下银膜层作为电极，当外加电场作用在电光聚合物波导层上，电光聚合物材料的折射率会产生微小变化，引起传播常数的变化，进而导致衰减全反射导模共振吸收峰的平移。选择工作角度在导模共振吸收峰下降延的中点附近，高阻硅棱镜的反射太赫兹波强度随所加电压而变化，即高阻硅棱镜的反射太赫兹波强度被施加于电极上的电场所调制，从而实现对太赫兹波信号高速调制。根据不同波长其同步角不一样的特性，通过改变不同频率太赫兹波的入射角可以实现对多个频率的太赫兹波信号调制。这样既不需要改变调制器结构，也不增加任何工艺制作难度，可以十分容易的实现对太赫兹波的频率可调谐和大调制带宽。最终实现对太赫兹波的高速、宽带信号调制。. 项目利用电控导模共振吸收和电光效应共同作用对太赫兹波进行高速信号调制和频率可调谐的机理，建立了相应理论分析模型，完成太赫兹波调制器结构优化设计、制作与测试。研究结果实现在0.1THz~1.5THz之间实现多个不同频率太赫兹波的信号调制，且信号调制速度达Mb/s量级，调制深度达80%。该调制器调制速度高，带宽大，工作电压低等特点，能很好推动太赫兹通信技术应用与发展。