摘要
改进了用于确定渐变平面波导折射率分布的反WKB方法,这种渐变折射率分布是从在WKB近似的条件下得到的本征方程用数值方法求得的。用改进的反WKB方法计算3种(指数、高斯和阶跃函数)折射率分布,结果验证了该方法的有效性。先用最小二乘法拟合测量得到的有效折射率,进而求出有效折射率函数,再利用改进的算法分布计算出各自的折射率分布,计算结果同精确值吻合得很好。计算出的波导表明折射率同精确值的绝对误差约为0.1%。
The improvement of inverse Wentzel-Kramer-Brillouin(WKB) method for refractive-index profile of a graded-index planar waveguide calculated numerically from the eigenvalue equation under the WKB approximation is extended. The practicality of this method is demonstrated by application to three types of refractive index distribution (exponential, Gaussian and step refractive index distribution).The refractive-index profiles calculated from the corresponding effective-index function,which can be found approximately by least-square fitting of a set of measured effective indexes, agree well with the exact profile. The absolute errors of the waveguide surface indexes calculated,with respect to the exact values, are about 0.1%.
出处
《应用光学》
CAS
CSCD
2004年第4期4-8,共5页
Journal of Applied Optics
关键词
WKB方法
有效折射率函数
光波导
WKB method
effective-index function
optical waveguide
