SOI亚微米脊形光波导模式特性研究

Investigation of the Mode Characteristics of SOI Submicron Rib Waveguides

光波导的小型化研究对于减小光波导分立器件的体积和提高其集成度至关重要,纳米级波导光传输特性对其横截面的几何尺寸非常敏感。本文讨论和分析了高、宽都小于500nm的脊形光波导的单模条件和偏振无关条件。研究表明,绝缘体上硅(SOI,Silicon-on-Insulator)亚微米脊形波导的模式特性与脊形微米级光波导是十分不同的,传统的有效折射率法等数值计算方法有其局限性,这里我们采用了快速准确的三维束传播(beampro pagation method,BPM)算法,得到亚微米脊形光波导满足单模和偏振无关条件的重叠截面尺寸参数。尤其,当波导高度为300nm,单模条件与400nm高度的波导开始有显著不同。因此,这些研究结论为构筑基于亚微米尺寸波导的光电子器件结构设计提供一定理论支持。

Miniaturization of waveguides is very important for reducing the dimensions of optoeleotronics devices and iraproving the integration of discrete derives. The mode characteristics of silicon-on-insulator （SOI）submieron rib wave guides are very sensitive to the profile and the dimension of waveguide cross-section. In this paper, we studied and analyzed the single-mode and polarization-independent oonditions for rib-waveguides with height and width less than 500nm. Our research shows the mode characteristics of sub-micrometer rib-waveguide are different from those of micrometer-sized ones.Conventional analyzing methods suoh as offective index method have their deficiency,here we have adopted a fast and acourate three-dimensional imaginary BPM （beam propagation method） algorithm,and found there exist an overlap regions of waveguide section parameters between single-mode oonditions and polarization-independent conditions.Especially.when the height of rib waveguide is 300 nan, the single-mode conditions me significantly different from that of 400nm ribheight. All these results provide an accurate theoretical model for oonstructing high-performance optoeleetronic devices based on sub-micrometer nano-wire waveguides.