Theoretical Analysis on Birefringence Compensation in Silica Optical Waveguide on Silicon
硅基二氧化硅波导的双折射效应补偿理论分析

Two kinds of polarization compensation ways for silica waveguide on silicon are analyzed by finite element method.It is shown that the polarization within silica waveguide can be compensated by making stress release grooves and adjusting thermal expansion coefficient of overcladding layer.The stress release groove is applied to release a compress stress introduced by a difference of thermal expansion coefficient between silica and silicon substrate,and to change the distribution of stress around the core.But,when its depth is over a certain value,the groove will modify and release the polarization of waveguide.In compensation with groove depth ,rove width does a little.The adjusting of thermal coefficient of overcladding compensates waveguide polarization,but that of undercladding layer or core layer has little effect.