Si衬底减薄及氧化对硅基二氧化硅波导应力双折射影响的数值分析

采用有限元法对硅基二氧化硅波导在玻璃化过程中的应力与Si衬底厚度和背面氧化层厚度的关系进行了系统的分析;在此基础上,应用全矢量有限差分束传播法(FD-BPM) 对应力光波导的双折射进行了分析.结果表明随着Si衬底厚度的减薄,波导附近水平方向和垂直方向所受应力趋于一致,双折射系数B可小于10~(-4);Si衬底背面氧化层的存在使双折射系数略有增大,但随氧化层厚度的增加可减缓其增加量.

Numerical Analysis of the Effect from the Si Substrate Thinning and Its Back Silica on Stress Birefringence of Silicon Waveguide

The relationship between stress distribution of silica on silica waveguide and Si substrate thickness or thickness of silica at the back of Si during sintering has been analyzed theoretically using a finite element method.At the same time,the stress birefringence of waveguide has been also analyzed by the full-vector finite difference beam propagation method.The results showed that the stresses between horizontal direction and perpendicular direction become equal gradually with decreasing of the Si thickness,and the birefringence index is less than 10~(-4).The birefringence index increases slightly due to the silica at the back of Si,and the increasing quantity becomes weaker with increasing of silica thickness.