非均匀折射率分布少模光纤光学特性研究
Optical Properties of Few-Mode Fiber with Non-Uniform Refractive Index
少模光纤 柱矢量光 非均匀折射率 少模光纤布拉格光栅 透射谱 few-mode fiber cylindrical vector beam non-uniform refractive index few-mode fiber Bragg grating transmission spectrum
摘要
以实现柱矢量光横向选模为目标, 研究了非均匀折射率分布的少模光纤的光学特性。利用有限元法分析了U型折射率分布和弯曲少模光纤的模场特性: 前者结合1 550 nm泵浦光可支持LP11模式并抑制LP01模式; 后者包括二模光纤和四模光纤, 当二者弯曲半径分别为4和2 cm时, 仅支持LP01和LP11模式。结合理论和实验研究了四模和二模FBG(光纤布拉格光栅), 对于二模FBG, 当透射波长位于1 549.79 nm附近时, 可获得呈两瓣分布的LP11模式; 对于四模FBG, 其反射谱峰值波长个数随尾纤弯曲半径的减小而减少。相关结果对于柱矢量光的产生和应用具有重要的理论和实践意义。
Abstract
This paper studies optical properties of few-mode fibers with non-uniform refractive index profile, namely: the U-shape refractive index few-mode fiber and the bending two-mode and four-mode fiber. Finite element method is used to analyze the modal profile of these few-mode fibers. The U-shape refractive index few-mode fiber can support LP11 mode and suppress LP01 mode with a proper pump at 1 550 nm. The two-mode fiber and four-mode fiber can only support LP01 and LP11 mode with a bending radius of 4 cm and 2 cm, respectively. Two-mode and four-mode Fiber Bragg Gratings (FBG) are also studied theoretically and experimentally. As to the two-mode FBG, LP11 mode distribution with a two-lobe shape is measured experimentally near a transmission wavelength of 1 549.79 nm. As to the four-mode FBG, the number of reflection peak wavelength is decreased with a lower bending radius.
李宏业, 万洪丹, 王杜毅, 欧琦, 王子康. 非均匀折射率分布少模光纤光学特性研究[J]. 光通信研究, 2016, 42(5): 46. LI Hong-ye, WAN Hong-dan, WANG Du-yi, OU Qi, WANG Zi-kang. Optical Properties of Few-Mode Fiber with Non-Uniform Refractive Index[J]. Study On Optical Communications, 2016, 42(5): 46.