以InP/InGaAsP脊形波导结构为研究对象, 采用有限元算法(FEM), 系统地仿真分析了在固定芯层厚度的情况下, 不同脊高和脊宽条件下脊形波导的单模特性和偏振特性。在芯层厚度一定的情况下, 脊宽越窄, 刻蚀深度越浅, 波导的传输模式越接近单模。在深刻蚀情况下, 脊波导模双折射系数受到脊宽的影响较大, 波导的偏振不敏感性较差; 在浅刻蚀情况下, 模双折射系数(Δn=nTE-nTM)受到脊宽和脊高的影响较为微弱, 稳定在1.2×10-3。相关仿真和分析为基于InP/InGaAsP脊波导的光电子器件的结构设计提供了一定的理论支持。

Theoretical analysis and simulations of the single mode condition and polarization sensitivity properties were reported for InP/InGaAsP rib waveguide, based on finite element method (FEM). The mathematic model of different rib width and height of InP rib waveguide was established, with the core height remain unchanged. With the narrow ridge width and shallow etching depth, the transmission mode characteristics is close to single mode condition. When it comes to deep etching, the mode birefringence index is much higher and easily affected by the rib width, but when it comes to shallow etching, the impact of rib width and height on the mode birefringence is very weak. And the mode birefringence index is stable at 1.2×10-3. The simulation results and analysis provide an accurate theoretical model for constructing high performance optoelectronic devices based on InP/InGaAsP rib waveguide.