2 μm工作波长下氮化硅槽波导特性研究
Characteristics of Silicon Nitride Slot Waveguide at a Wavelength of 2 μm

2 μm波段在光通信、光传感等领域拥有巨大前景，应用的蓬勃发展带来了与日俱增的器件需求，其中低损耗的氮化硅波导备受关注。本文利用有限元模场求解法，系统地研究了2 μm工作波长下氮化硅槽波导的模式截止条件、模式分布特性、色散特性和偏振特性。研究结果表明，氮化硅槽波导的氮化硅条宽度、槽宽度和波导高度均影响其模式截止条件、模式分布特性、色散特性和偏振特性。通过结构优化设计，氮化硅槽波导的最高槽中功率限制因子可达16.5%，氮化硅波导的色散特性可用于2 μm波段的色散补偿，氮化硅波导的偏振特性可用于2 μm波段的偏振分束等。本文的工作可为2 μm波段的波导器件提供一个有力候选，为氮化硅槽波导在2 μm波段的应用提供理论基础。
The 2 μm band has great prospects in optical communication, optical sensing and other fields. With the rapid development of applications, the demand for devices is increasing day by day, among which the low loss silicon nitride waveguide is attracting more and more attention. In this paper, the mode cutoff conditions, mode distribution, dispersion characteristics and polarization charac-teristics of silicon nitide slot waveguides at 2 μm operating wavelength are systematically studied by means of finite element method. The results show that the width of the silicon nitride slot wave-guide, the width of the slot and the height of the waveguide all affect the mode cutoff condition, the mode distribution, the dispersion characteristics and the polarization characteristics. By optimizing the structure, the highest power confinement factor of the silicon nitride slot waveguide can reach 16.5%. The dispersion characteristics of the silicon nitride waveguide can be used for dispersion compensation in 2 μm band, and the polarization characteristics of the silicon nitride waveguide can be used for polarization beam splitting in 2 μm band. The work in this paper can provide a strong candidate for waveguide devices in 2 μm band and establish theoretical basis for the appli-cation of silicon nitride slot waveguides in 2 μm band.