为了实现纳米激光器的性能优化, 设计了一种基于纳米线、半圆形氟化镁、三角形空气槽和金属脊结构的纳米激光器模型。模型中耦合在低折射率电介质层中的SPP模式和纳米线波导可以在低折射率间隙下像电容器那样存储光能, 从而使低折射率的空气槽场强明显增大。应用有限元法在COMSOL Multiphysics软件下, 分析了该纳米激光器模型的电场分布、模式特性、品质因数和增益阈值随着设计结构几何参数变化的规律, 通过各部分折线图的综合分析来得出模型性能的数据。分析表明: 该模型的光场约束能力较强且传播损耗较低, 其中归一化面积最小可达到0.004 8, 有效传输损耗最小可达到0.002。波导模场区域和限制因素表明, 该激光器模型可以实现输出光场的亚波长约束。该模型基本实现了低增益阈值、低传输损耗和高品质因数的要求。

In order to optimize the performance of nanolasers, a nanolaser structure based on a nanowire/semicircle MgF2/triangle air slot and metal ridge was proposed. The models produce that the SPP mode and nanowire waveguides coupled in the dielectric layer of low refractive index can store light energy like a capacitor under low refractive index clearance. Low refractive index of the air tank field strength increased significantly. The electric field distribution, the modal properties, the quality factor and the lasing threshold are investigated by using the finite-element method on the basis of the COMSOL Multiphysics platform. Through the comprehensive analysis of each part of the line chart, the model performance data are obtained. Simulation results reveal that this kind of nano laser has a low propagation loss and high field confinement ability, its minimum normalized mode area is only 0.004 8, the minimum propagation loss is only 0.002. The waveguide mode field area and limiting factors show that the modeled laser can achieve sub-wavelength constraints of the output light field. It can achieve low gain threshold, low transmission loss and high quality factor requirements.