【摘要】 在绝缘层上的硅材料上制作了四种具有不同输入输出结构的星形耦合器并进行了测试 ,对脊形波导与平板波导相互过渡时过渡区的损耗问题进行了研究和讨论 ,计算得到在所使用的材料参量下利用锥形结构可以得到1dB左右的最小损耗 ,这一损耗是由于脊型波导与平板波导间的模式失配造成的。以文献中的实验数据为出发点 ,分析了脊形波导的偏振问题 ,并通过对脊型波导器件层厚度、脊高、脊宽进行优化设计 ,得到了不同偏振模式的有效折射率差仅为 10 -5量级的单模脊型波导结构 ,这样的偏振效应在器件设计中可以忽略。更多还原

【Abstract】 Four kinds of star couplers with different structures at rib-to-slab and slab-to-rib transition region on silicon-on-insulator are fabricated. The testing results are consistent with the theoretical calculation in which transition loss about 1 dB by using taper waveguides was obtained. The loss is caused by mode dismatching between the rib waveguides and slab waveguides. Polarization effect in SOI rib waveguides is also discussed. Experimental data in the released literature are quoted to validate the analysis method. And the effective index difference which is as low as 10 -5 order between two polarizations of single mode rib waveguides is obtained by optimal design for the rib waveguide thickness, rib height, rib width. In fact this so little effect can be neglected in practical design.更多还原