【摘要】 以柱坐标下的半矢量波动方程为基础,采用基于完美匹配层(PML)边界条件的有限差分方法,对弯曲波导进行模式求解,进而得到波导弯曲引起的辐射损耗。基于计算得到的直弯波导的模场分布,采用二维重叠积分法计算了两者连接时的过渡损耗。计算结果与已有实验结果符合较好。采用该方法,研究了SOI脊型波导的弯曲损耗与波导结构参数之间的关系,并对直弯波导的连接进行了优化。更多还原

【Abstract】 Based on the semi-vector wave equation under cylindrical coordinate system,the mode distribution and complex propagation constant in bent waveguides were computed by a finite difference method with perfectly matched layer(PML) boundary condition.The radiation loss was obtained from the imaginary part of the complex propagation constant and the transition loss was calculated by two-dimension overlap integral method.In comparison with the experimental results by Deri,the calculation result is rather accurate.The relationship between bending loss and the structural parameters of SOI rib waveguide was analyzed by the method presented,and the offset at the junction of bent and straight rib waveguides was optimized as well.更多还原