With the rapid development of optoelectronic fibers of multi-materials and structures, coupling between the optoelectronic fibers and the conventional optical fibers with high transmission is desirable. In this article, we propose a mode coupler to facilitate the transmission of electromagnetic wave from a dielectric fiber to a simple metal-core optoelectronic fiber in the terahertz regime. The coupler mainly consists of an air cone along its symmetric axis. The transmission characteristics of the terahertz wave of the frequency ranging from 2 to 8 THz for five hybrid modes are investigated using finite difference time domain method. We show the dependence of the transmission on the height of the air cone for the selected frequencies.

随着多种材料和结构的光电光纤的快速发展，光电光纤与传统光纤之间的高传输耦合是人们所期望的。在本文中，我们提出了一种模式耦合器，以促进电磁波在太赫兹范围内从电介质光纤传输到简单的金属芯光电光纤。耦合器主要由沿其对称轴的空气锥组成。使用有限差分时域方法研究了频率范围为2至8 THz的五种混合模式的太赫兹波的传输特性。我们展示了传输对所选频率的空气锥高度的依赖性。