各向同性光波导受到各向同性微扰时的严格矢量耦合模理论

从Maxwell方程出发，推导出各向同性光波导受到各向同性微扰时严格的非正交矢量耦合模理论，在耦合系数的表达式中发现不包含Wei-Ping Huang 的准矢量耦合模理论中的偏振耦合项，但在推导过程中曾出现过偏振耦合项.最后认为这是由于偏振耦合项是二阶小量，而弱导近似忽略了与之相等的二阶小量耦合项.因此,严格的矢量耦合模理论不存在该项而准矢量耦合模理论可把偏振耦合项作为修正项.

The Rigorous Vectorial Coupled-Mode Theory for the Isotropic Optical Waveguide with Isotropic Disturbances

The rigorous nonorthogonal vectorial coupled-mode theory is presented for the isotropic waveguide with isotropic disturbances, based on the Maxwell Equation. The coupling term due to polarization, which is presented in the scalar coupled-mode theory with the vector correction of the Wei-Ping Huang, isn't included in this rigorous vectorial coupled-mode theory, and the term is emerged during the derivation. It is because that the coupling term due to polarization and the ignored term due to the weakly guiding approximation are as small as the second order, and they are just the same. Therefore, the rigorous vectorial coupled-mode theory has not the coupling term due to polarization which can be looked as the vector correction for the scalar coupled-mode theory.