【摘要】 针对太赫兹调制器件比较匮乏,导致太赫兹技术在各领域的发展缓慢的问题,利用石墨烯与氧化钒2种材料的特性,设计了一种基于氧化钒与石墨烯复合结构的光诱导宽带大深度太赫兹调制器。在高阻硅基底的一个表面转移石墨烯,在另一个表面用匀胶法制备氧化钒薄膜。中心波长为650 nm的泵浦激光分别从氧化钒与石墨烯表面入射,不但诱导氧化钒发生了绝缘体-金属相变,而且引起石墨烯费米能级改变,以实现对透射太赫兹波强度的调制。当2束泵浦光的功率为80 mW时,在0.2～1.6 THz的宽频带范围内最大调制深度高达92%。该器件制作工艺简单,可调频带宽,可在低光功率下实现大调制深度,在未来全光太赫兹通信系统中具有重要的应用价值。更多还原

【Abstract】 To solve the problem that the terahertz modulator is in short supply, which leads to the slow development of terahertz technology in various fields, a broadband and large modulation depth terahertz modulator based on the composite structure of vanadium oxide and graphene is experimentally demonstrated by using the characteristics of graphene and vanadium oxide. Firstly, a layer of graphene is transferred to one surface of the high resistance silicon substrate, and then a layer of vanadium oxide film is spin coated on the other surface. Two pumping lasers with central wavelength of 650 nm are oblique incident from two sides of the sample at the same time. The transmitted terahertz wave is modulated by intensity of the pumping laser, because the incident laser can not only induce the insulator-to-metal phase transition of the vanadium oxide film, but also change the Fermi energy level of the graphene. When the power of two pumping lasers is 80 mW, the maximum modulation depth achieved 92% in a wide frequency range of 0.2-1.6 THz. This modulator has many advantages, such as simple manufacturing process, broad tunable bandwidth, and large modulation depth at low pumping powers. Therefore, it should be very important for all-optical terahertz communication in the further.更多还原