通过理论计算获得了全反射时分层介质中p偏振光的透射系数计算公式, 并采用时域有限差分(FDTD)方法进行了验证。计算所获得的公式与传统的采用分层介质的特性矩阵法计算获得的相似, 不同之处在于当发生全反射时, 公式多了一个全反射修正因子。此外, 采用FDTD模拟的两层介质的全反射结构及表面等离子体共振(SPR)膜系结构的结果与修正后的公式符合得很好。该修正公式是对分层介质中电磁波传播的完善, 是对一些有影响力的文献关于场增强因子的修正, 它对SPR及倏逝场的研究具有参考价值。

The computing formula of the electric field strength transmission coefficient of p polarized light in layered media is obtained by theoretical computation, and verified by finite difference time domain(FDTD) method. This formula is similar with that of the traditional transmission coefficient of p polarized light in layered media computed by characteristic matrix method. The difference is that when the total internal reflection (TIR) occurs, a TIR correction factor arises. Furthermore, a two layer TIR structure and a surface plasmon resonance (SPR) film structure are simulated by FDTD method, and the results are in good agreement with those of the correction formula. This correction formula is a perfection to the propagation of electromagnetic wave in layered media, and an amendment to some influential references about the description of the field enhancement factor. It also has reference value for the researches on SPR and the evanescent field.