设计了一种新型的基于金属表面等离子体激元(SPPs)的亚波长金属-绝缘体-金属(MIM)型类电磁诱导透明(EIT)系统,该系统由-个直波导及其两边对称的齿形腔和纳米盘耦合而成。利用耦合模式理论对结构进行分析,并通过时域有限差分方法(FDTD)进行数值模拟。当齿形腔和纳米盘的共振频率相近,可以获得类EIT效应,改变齿形腔的长度和纳米盘的半径可以调节透明窗的位置。该装置可以用作高性能的类EIT滤波器,透过率高达77.5%,半高宽低至35.5nm,群指数高达65,为高度集成光网络提供了一种新的方法,可应用于波长选择器、超快开关、光存储等设备。
A novel sub-wavelength metal-insulator-metal (MIM) type electromagnetically induced trans- parency (EIT) system based on metal surface plasmon polaritons (SPPs) is designed. It is composed of a straight waveguide coupled with symmetrical stub cavities and nanodisks. The structure is analyzed by the coupling mode theory and numerical simulation is carried out with the finite-difference time-domain (FDTD) method. When the resonant frequencies of the stub cavities and nanodisks are about the same, EIT-like effect can be obtained. The position of transparent window can be adjusted by changing the stub cavity length and radii of the nanodisks. The device can be used as a high performance EIT-like filter with transmission rate up to 77.5%, full width at half-maximum (FWHM)less than 35.5 nm and group index over 65. The system provides a new method for the highly integrated optical networks. It can be applied to wavelength selector, ultrafast switching, optical storage and other devices.