Zhao Yong, Chen Yuxuan, Hao Lijun
School of Science, Jiangsu Provincial Research Center of Light Industrial Optoelectronic Engineering and Technology, Jiangnan University, Wuxi 214122, China.
Department of Electronic Engineering, School of Internet of Things Engineering, Jiangnan University, Wuxi 214122, China.
Materials (Basel). 2024 Dec 19;17(24):6213. doi: 10.3390/ma17246213.
We propose two types of structures to achieve the control of Fano and electromagnetically induced transparency (EIT) line shapes, in which dual one-dimensional (1D) photonic crystal nanobeam cavities (PCNCs) are side-coupled to a bus waveguide with different gaps. For the proposed type Ⅰ and type Ⅱ systems, the phase differences between the nanobeam periodic structures of the two cavities are and 0, respectively. The whole structures are theoretically analyzed via the coupled mode theory and numerically demonstrated using the three-dimensional finite-difference time-domain (3D FDTD) method. The simulation results show that the proposed structure can achieve several kinds of spectra, including Fano, EIT and asymmetric EIT line shapes, which is dependent on the width of the bus waveguide. Compared to the previously proposed Fano resonator with 1D PCNCs, the proposed structures have the advantages of high transmission at the resonant peak, low insertion loss at non-resonant wavelengths, a wide free spectral range (FSR) and a high roll-off rate. Therefore, we believe the proposed structure can find broad applications in optical switches, modulators and sensors.
我们提出了两种结构来实现对法诺和电磁诱导透明（EIT）线形的控制，其中双一维（1D）光子晶体纳米束腔（PCNCs）通过不同的间隙与总线波导侧面耦合。对于所提出的Ⅰ型和Ⅱ型系统，两个腔的纳米束周期结构之间的相位差分别为 和 0。通过耦合模理论对整个结构进行了理论分析，并使用三维时域有限差分（3D FDTD）方法进行了数值验证。仿真结果表明，所提出的结构可以实现包括法诺、EIT和非对称EIT线形在内的几种光谱，这取决于总线波导的宽度。与先前提出的具有1D PCNCs的法诺谐振器相比，所提出的结构具有谐振峰处高透射率、非谐振波长处低插入损耗、宽自由光谱范围（FSR）和高滚降率的优点。因此，我们相信所提出的结构可以在光开关、调制器和传感器中找到广泛的应用。
