基于渐变包络近似(SVEA)研究了非线性薄膜波导的TE模传输特性,得到了较为简洁的模式本征方程和导波的电磁场分布规律。对于芯区为自聚焦Kerr型介质,随着光功率强度的增大,导波的有效折射率增大,芯区中的传输功率比也增大,非线性介质的自聚焦效应就愈加明显。研究还表明,利用渐变包络近似得到的相关规律不仅简单清晰,而且十分有效,在光功率强度不太大时有很高的精确度。

Based on the slowly varying envelope approximation (SVEA),the transmission characteristic of the TE mode in the nonlinear thin film waveguide was studied.Concise mode eigenequation and electromagnetic field distributions of guided wave were obtained.For the Kerr medium whose core area is self-focusing,with the increase of the light power intensity,effective refractive index of guided wave increases and the transmission power rate in the core area increases,the self-focusing effect is more obvious.Studies also showed that the regulations obtained by the slowly varying envelope approximation are not only simple and clear,but also very effective,with a high accuracy when the intensity of light power is not very high as well.