A wavelength-selective optical switch by thermally controlling which has higher transmittance at metallic phase of Vanadium dioxide (VO₂) and lower transmittance at insulating phase is presented. By skillfully designing the structure, magnetic polaritons (MPs) are excited to enhance transmission to 0.79 indicating “on” mode with VO₂ at metallic phase. The coupling between two magnetic polariton modes is excited at the same frequency to suppress the transmittance peak to 0.045 indicating “off” mode with VO₂ at insulating phase, demonstrating tunability by over an order of magnitude during phase transition. Magnetic polariton coupling mode is proposed to explain the phenomenon of surpressed transmission and the electromagnetic field distributions confirm it. The proposed optical switch still works well at a large oblique incidence and the resonant frequency does not change with the incident angle. Our study may benefit the microelectronics and infrared active filtering applications.

提出了一种通过热控制的波长选择光开关，该开关在二氧化钒（VO ₂）的金属相上具有较高的透射率而在绝缘相处具有较低的透射率。通过巧妙地设计结构，磁极化子（MPs）得以激发，从而将透射率提高至0.79，表明在金属相中VO ₂具有“接通”模式。以相同的频率激发两个磁极化子模式之间的耦合，以将透射率峰值抑制到0.045，指示VO _2为“关”模式在绝缘阶段，在相变过程中可调谐性提高了一个数量级。提出了磁极化耦合模式来解释传输抑制现象，电磁场分布证实了这种现象。所提出的光开关在大斜入射下仍能很好地工作，并且谐振频率不会随入射角而变化。我们的研究可能有益于微电子学和红外有源滤波应用。