研究了紫外表面等离激元在半导体纳米线-绝缘介质-金属构成的波导结构中的输运问题,借助有限元方法,对这种波导所支持导模的电磁能分布、有效折射率、传播长度和有效模场面积随电磁参数和几何结构参数的依赖关系进行了分析。计算结果表明:以氧化锌纳米线作为增益介质,绝缘材料选择折射率小的空气,金属选择铝能够实现对输出光场的亚波长约束,有效模场面积达到λ2/100,同时保持低的传输损耗和高场强限制能力;有望用作纳米光源,使得相关的生物探测器件和医疗诊断设备实现更高的灵敏度和更小的体积。
Ultraviolet surface plasmon polariton propagation for ZnO semiconductor-insulator-metal waveguide is investigated by means of the finite-element method. The field distribution, effective refractivity, propagation distance, and mode area of the hybrid mode supported by the waveguides were detailed analyzed, which are dependent on the dielectric constant and geometrical parameters. In order to achieve low propagation loss and subwavelength field confinement, several materials are calculated. Our investigation indicated that air and aluminum are better, which act as the insulator and metal respectively, and the effective mode area of such a waveguide can be as small asλ2/100. The results can help the development of nano-sized light sources which can enhance the sensitivity for bio-detection devices and diagnostic equipments.