设计了一种金属三角肋和增益介质三角肋完全对称并带有圆柱形空气缝隙的新型混合等离子体波导结构。采用COMSOL Multiphysics软件,分别仿真了波导的二维和三维耦合电场分布模型,并基于有限元法分析了波导的模式特性。研究结果表明:当工作波长为1550 nm时,设计的波导结构具有很强的光场约束能力、超长的传输距离、超低的传输损耗和增益阈值。对波导的结构参数进行了优化,当波导的有效模场面积达到0.0022λ2时,波导的传输距离能够达到69805 nm,传输损耗低至0.0017;基于此波导的激光器也具有很低的增益阈值,为49.3 cm -1。最后研究了实际制备过程中可能出现的制作误差对波导性能的影响,并分析得出此波导结构对制作误差具有较高的容忍度。与同类型带有空气缝隙的波导结构相比,此波导的综合性能更优,在各种集成纳米光子设备中具有很大的应用潜力。

In this study, a novel hybrid plasma waveguide with a cylindrical air gap and fully symmetrical metal and gain medium triangular ribs was designed. The two- and three-dimensional coupled electric-field-distribution models of the waveguide were built using COMSOL Multiphysics software. The mode characteristics of the waveguide were analyzed based on the finite element method. Results indicate that the designed waveguide exhibits strong optical field constraint capability, overlong propagation distance, ultra-low propagation loss, and gain threshold at 1550-nm operating wavelength. We optimize the structural parameters of the waveguide, and when the effective mode field area of the waveguide reaches 0.0022λ2, the propagation length and propagation loss are 69805 nm and 0.0017, respectively. Furthermore, the laser based on the waveguide exhibits a low gain threshold of 49.3 cm -1. Finally, the tolerance of the waveguide performance against these possible fabrication imperfections is analyzed. It is concluded that the waveguide structure exhibits good tolerance to possible fabrication imperfections. Compared with the same type of waveguide structures with air gap, the waveguide demonstrats good comprehensive performance and great potential in various integrated nanophotonic devices.