具有非均匀渐变界面DBR的光学特性分析

应用特征矩阵法研究了非均匀渐变界面Al_0.9Ga_0.1As/Al_yGa_1-yAs/GaAs/Al_xGa_1-xAs DBR的光学特性.建立了非均匀渐变界面Al_yGa_1-yAs的折射率模型，并得到了渐变界面特征矩阵的解析解，通过特征矩阵法分别计算了突变GaAs/Al_0.9Ga_0.1As DBR和渐变DBR的反射谱和反射相移，分析了非均匀渐变层对DBR光学特性的影响，对渐变DBR，需要在DBR前面再增加一定厚度的非均匀渐变相位匹配层才能使整个DBR满足中心波长相位匹配条件，并通过光学厚度近似方法求出相位匹配层厚度.关键词：DBR反射谱反射相移特征矩阵法

Optical characteristics of DBR with inhomogeneous graded interfaces

Optical properties of Al0.9 Ga0.1 As/Aly Ga1-y As/GaAs/Alx Ga1- x As DBR with inhomogeneous graded interfaces has been investigated by using characteristic matrix method. The refractive index model and the analytic characteristic matrix of graded interfaces are obtained. The reflectance spectrum and the reflective phase shift are calculated for GaAs/Al0.9 Ga0.1 As DBR and graded interfaces DBR by using characteristic matrix method. The effect of graded interfaces on the optical properties of DBR is discussed. The result shows an extra graded phase matching layer must be added in front of the graded interfaces DBR to fulfil the conditions of phase matching at central wavelength. The accurate thickness of phase matching layer is calculated by optical thickness approximation method.