标题： 多层麦克斯韦鱼眼透镜作为波导交叉 显示英文标题

标题： Multilayered Maxwell's fisheye lens as waveguide crossing

摘要： 麦克斯韦鱼眼（MFE）透镜，由于其聚焦特性，是实现多根波导交叉的有趣候选方案。 MFE透镜通过两种不同的结构实现：同心圆柱多层结构和径向发散的葫芦形杆结构。 通过控制由有效介质理论确定的交替Si和SiO2层的厚度比来实现透镜的折射率分布。 这两种结构都优化以在单模实现中覆盖整个C波段。 基于环形的结构的传输效率优于基于径向的实现，然而，基于径向的结构也几乎覆盖整个U波段。 在两种情况下，其他通信波段部分被覆盖。 全波仿真证明，基于半径为2.23\mu m的MFE透镜的多模波导交叉性能是有前景的，在C波段对于TM0和TM1模式，平均插入损耗为0.17dB，串扰水平低于-24.2dB。 多模交叉几乎覆盖了光通信的整个C、L和U波段。 显示英文摘要

摘要： The Maxwell's fisheye (MFE) lens, due to its focusing properties, is an interesting candidate for implementing the crossing of multiple waveguides. The MFE lens is implemented by two different structures: concentric cylindrical multilayer and radially diverging gourd-shaped rods. Realization of the refractive index profile of the lens is achieved by controlling the thickness ratio of the alternating Si and SiO2 layers determined by effective medium theory. Both structures are optimized to cover the entire C-band in the single mode implementation. The transmission efficiency of the ring-based structure is superior to the radial-based implementation, however, the radial-based structure almost covers the entire U-band as well. Other communication bands are partially covered in both cases.Full-wave simulations prove that the performance of multimode waveguide crossing based on the MFE lens with a radius of 2.23 \mu m is promising with the average insertion loss of 0.17dB and crosstalk levels below -24.2dB in the C-band for TM0 and TM1 modes. The multimode intersection almost covers the entire C, L, and U bands of optical communication.