利用转移矩阵理论分析了任意折射率分布平板波导的传输特性,导出了非均匀平板波导的近似解析色散方程,并指出了WKB近似的局限性.数值比较的结果表明,文中所得公式的精确度优于传统的WKB方法和其它近似方法.

A new method for obtaining the analytical dispersion characteristics of planar waveguides with arbitrary refractive index profile is presented. The method is based on the transfer matrix theory and a new interpretation of the WKB approximation is proposed. A comparison with other methods and the exact numerical results shows that our method is much more accurate than the ordinary WKB method and other existing approximate methods.