Power coupling between fiber and multimode slab composite waveguide
- 作者：Kapoustine ; Valeri V. ; Yarovikov ; Sergey O.
- 关键词：42.82.Et ; Optical coupler ; Fiber ; Composite planar waveguide ; Power-coupling coefficient
- 刊名：Optics Communications
- 出版年：2002
- 期刊代码：50_00304018
- 类别：ph
- 出版时间：April 1, 2002
- 卷：204
- 期：1-6
- 页码：171-178
- 文件大小：2.31 M
摘要
We discuss power coupling in devices composed of a fiber with partly or completely removed cladding and multimode slab overlay waveguide of any complexity. A fiber mode excites with a high efficiency only one mode of the composite structure in the wide range of system parameters. But only when the effective refractive index of this mode almost equals to the one of the initial fiber mode the modal value of electric field is high enough to produce effective interactions with active and passive elements in the region of the overlay waveguide. In the narrow range of system parameters last two modes are excited with a nearly equal efficiency providing a regular directional coupler. The power-coupling coefficient essentially depends on the thickness of remaining fiber cladding and an optimal value of this cladding is about 1.5–2 μm.