Roumi Bita, Abbasi Masoumeh, Fallahi Vahid, Li Ying, Shou Yifan, Abdi-Ghaleh Reza
Department of Laser and Optical Engineering, University of Bonab, P.O. Box 5551395133, Bonab, Iran.
International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China.
Sci Rep. 2025 Mar 17;15(1):9222. doi: 10.1038/s41598-025-93843-3.
Magneto-optic effects are demonstrated to be an effective method for light modulating with an external magnetic field. A novel thermally induced switching mechanism is introduced for manipulating magneto-optical Faraday and Kerr rotations in the terahertz (THz) range. The innovative design consists of a composite of Vanadium dioxide (VO) and graphene layers, which involves a MgO defect layer positioned on top of a graphene sheet sandwiched between dual Bragg reflectors, all mounted on a VO layer. This unique configuration allows for switchable and enhanced magneto-optical responses in transmission and reflection geometries stemming from the temperature-dependent semiconductor-to-metal transition of the VO layer. The magneto-optical properties of the switching structure were analyzed using the transfer matrix method, revealing the emergence of a mode within the 2-3 THz range at temperatures of 300 K and 350 K. At 300 K, this mode displays significant transmission with an absolute Faraday rotation angle of approximately 15.26˚ and minimal reflection. Upon increasing the temperature to 350 K, the mode shifts to a reflective state at the same frequency, exhibiting negligible transmission and a Kerr rotation angle of approximately 44.18˚. Furthermore, the switching mode remains stable for both s- and p-polarizations for incidence angles near normal. Importantly, the thickness of the defect layer plays a crucial role in determining the position and intensity of the switching mode. This thermally controlled switching structure is important for advancing and implementing optoelectronic devices, offering valuable insights for designing and optimizing multifunctional systems.
磁光效应被证明是一种利用外部磁场进行光调制的有效方法。本文介绍了一种新颖的热诱导开关机制，用于在太赫兹（THz）范围内操纵磁光法拉第旋转和克尔旋转。这种创新设计由二氧化钒（VO）和石墨烯层的复合材料组成，其中包括位于夹在双布拉格反射器之间的石墨烯片顶部的氧化镁缺陷层，所有这些都安装在VO层上。这种独特的结构允许在透射和反射几何结构中实现可切换和增强的磁光响应，这源于VO层随温度变化的半导体到金属的转变。使用传输矩阵方法分析了开关结构的磁光特性，发现在300 K和350 K温度下，在2-3 THz范围内出现了一种模式。在300 K时，这种模式显示出显著的透射率，绝对法拉第旋转角约为15.26˚，反射率最小。当温度升高到350 K时，该模式在相同频率下转变为反射状态，透射率可忽略不计，克尔旋转角约为44.18˚。此外，对于接近法线的入射角，开关模式对于s偏振和p偏振都保持稳定。重要的是，缺陷层的厚度在确定开关模式的位置和强度方面起着关键作用。这种热控开关结构对于推进和实现光电器件非常重要，为设计和优化多功能系统提供了有价值的见解。
