物理专业论文翻译！！一段50分~求教啦~（2）

来源：百度知道 编辑：UC知道 时间：2024/05/15 19:20:31
For reasons of speed it is therefore usual to employ an “approximate” method-i.e., one which cannot converge to an exact solution no matter how precisely it is implemented. The most common of such approximations is the WKB method [4]-[9] applied ideally to profiles without an abrupt substrate interface. Diffused guides are closely approximated by this method and for them it produces fast and reasonably accurate solutions and is able to perform the reverse calculation directly (i.e., from modes to profile) provided that a “free profile” is used (i.e., one using thickness coordinates for each mode level) [4], [5]. Unfortunately, however, the simple WKB approximation may be inapplicable to steep-sided profiles (e.g., proton exchanged or epitaxially grown) where, for these almost square cases, it is more appropriate to use a perturbation theory approach. The criteria for the choice between these approximations ha

楼主三个帖子都已翻好，应该说八九不离十了，请审阅。专业性很强，本人对光纤比较熟悉，所以光波导有相近之处。
For reasons of speed it is therefore usual to employ an “approximate” method-i.e., one which cannot converge to an exact solution no matter how precisely it is implemented. 出于对速度的考虑，因此通常采用一种近似方法，即不管如何精密实施都不能收敛于一个准确解的方法。The most common of such approximations is the WKB method [4]-[9] applied ideally to profiles without an abrupt substrate interface. 这种近似方法中最常用的就是WKB近似法【4－9】，它被理想地用于了没有突变基体界面的折射率分布。Diffused guides are closely approximated by this method and for them it produces fast and reasonably accurate solutions and is able to perform the reverse calculation directly (i.e., from modes to profile) provided that a “free profile” is used (i.e., one using thickness coordinates for each mode level) [4], [5].扩散波导用这种方法进行了逼近近似，而对这些波导来说，该方法产生了快速而合理精确的解，而且能够直接进行反面求解（即从模式到折射率分布），条件是采用一种“自由的分布”（即采用厚度坐标用于每一模式层次）【4】，【5】。 Unfortunately, however, the simple WKB approximation ma