Lin Mi, Fu Lixin, Ahmed Shakeel, Wang Qiong, Zheng Yaoxian, Liang Zixian, Ouyang Zhengbiao
THz Technical Research Center of Shenzhen University, Shenzhen Key Laboratory of Micro-Nano Photonic Information Technology, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen 518060, China.
Nanomaterials (Basel). 2021 Feb 2;11(2):381. doi: 10.3390/nano11020381.
We propose a type of polarization-independent circulator based on a composite rod of ferrite and plasma materials in a two-dimensional photonic crystal (PhC) slab. Only one composite rod was set at the center of the structure to provide circulation for both TE- and TM-polarized waves. Additionally, to improve the performance of the circulator, three additional rods were inserted to improve the coupling condition between the center magneto-optical microcavity and the corresponding waveguides. Finite element method was used to calculate the characteristics of the structure and the Nelder-Mead optimization method was employed to obtain the optimum parameters. The results show that a low insertion loss (0.22 dB) and high isolation (14 dB) can be achieved in our structure for waves of both TE and TM polarizations. The idea presented here may be useful for designing compact polarization devices in large-scale integrated photonic circuits.
我们提出了一种基于二维光子晶体（PhC）平板中由铁氧体和等离子体材料组成的复合棒的偏振无关环行器。仅在结构中心设置一根复合棒，以实现TE偏振波和TM偏振波的循环。此外，为了提高环行器的性能，插入了另外三根棒以改善中心磁光微腔与相应波导之间的耦合条件。使用有限元方法计算结构的特性，并采用Nelder-Mead优化方法获得最佳参数。结果表明，对于TE和TM偏振波，我们的结构可以实现低插入损耗（约0.22 dB）和高隔离度（约14 dB）。这里提出的想法可能有助于在大规模集成光子电路中设计紧凑的偏振器件。
