【作者】 杨义；

【导师】 侯蓝田；

【作者基本信息】 燕山大学 ， 电路与系统， 2003， 硕士

【摘要】 随着红外激光技术的发展，出现了各种各样用来传输激光能量的空芯光纤。虽然这些光纤已经被广泛用于在较低损耗下传输红外激光能量，但是现有的关于空芯光纤的传输理论还不能很好地解释空芯光纤中的损耗与模式特性。现有应用较广的M-S理论和Miyagi公式只能适用于特定类型的光纤，而且这两种理论的预测值与实验结果存在一定的偏差。为了能更好地对这一类型的光纤进行分析，就需要有新的理论对空芯光纤的传输特性进行解释。在本文中，我们将通过电磁场的推导并结合介质膜特性，提出一种全新的空芯光纤传输理论。 首先，论文结合实验，对现有空芯光纤传输理论进行了分析。通过比较实验中取得的结果和应用现有空芯光纤传输理论预测的空芯光纤中传输特性的差异，我们找到了现有空芯光纤传输理论预测与实验结果存在误差的原因。 其次，我们通过对Maxwell方程的推导，提出了空芯光纤中各向电磁场分量的解，在此基础上我们得到了空芯光纤的特征方程。同时我们还使用数值方法求得了空芯光纤中的特征参数并通过引入玻印亭矢量独立求得了空芯光纤中各模式的径向能量分布。 我们还在对空芯光纤中径向能量分布和介质表面反射特性研究的基础上，给出了介质膜与常规界面的反射特性的差异。通过二者的对比，我们得到了介质膜ATR(Attenuation total reflectance)光纤传输特性优于常规ATR空芯光纤的原因。 论文的最后，我们提出了一个关于空芯光纤传输特性新的理论体系。在这一理论体系中，我们得到了空芯光纤的输入特性和光纤直线状态下与弯曲状态下的损耗公式。最后我们比较了使用这一理论的数值解法求得的预测值与实验结果的关系。通过比较，我们发现使用这一理论可以得到与实验结果符合得较好的结果。更多还原

【Abstract】 With the development of IR laser technology, many kinds of hollow waveguide were made to deliver IR light. Those kinds of waveguide have got the ability that could be used to deliver high energy IR light with low attenuation. But these attenuation phenomena can’t be explained by current theory about character in hollow waveguide. So that it is impossible to look for some new theory to explain the character about energy deliver in hollow waveguide. In this paper, we concentrate on new theory about energy deliver in hollow waveguide.Firstly analyses of the energy delivering character are given by compared current theory about character in hollow waveguide to the result got by experiment. Through this way, we got the causation why current theory forecast mistake result.Secondly we get the electromagnetic distributions in hollow waveguide by doing some operations on Maxwell formula. We also get the characteristic formula in hollow waveguide. The characteristic parameter about hollow waveguide is gained by using numerical method and the energy distribution model is made by using vector.Thirdly we discuss the Z-direction energy distribution in hollow waveguide and reflecting character on interface. By giving analyses of this, we compare the normal ATR hollow waveguide to the medium layer ATR hollow waveguide and get the reason why the medium layer ATR (Attenuation total reflectance) hollow waveguide have an advanced delivering character.Finally a new theory about energy delivering in hollow waveguide is given. In this theory the input attenuation in both straight and bent hollow waveguide. We also use numerical method to solve this theory and the result got by this theory is given too.更多还原