一种新型轨道角动量光纤的设计与研究

Design and research of a new type of orbital angular momentum optical fiber

摘要:

随着光通信的不断发展与技术的迭代,传统光纤的容量与性能已经远远不能满足人们对通信的需求,提高光通信的系统容量和性能指标依然是迫在眉睫的重要研究内容。于是,设计出一种能传输大容量通信的光纤便极为重要。轨道角动量(Orbital Angular Momentum, OAM)根据其理论上的无限容量和极好的性能脱颖而出,为突破传统光纤的容量极限等问题,光子晶体光纤(Photonic crystal fiber, PCF)由于其多变的结构和灵活的材料选择而脱颖而出,并广受科研界关注。本文以OAM技术为基础,设计并研究出了一种新型PCF,利用有限元法对所涉及的PCF进行仿真。根据仿真实验得出,改变空气孔的参数和材料设计所得的新型PCF在1300-1700 nm波长范围内最多能够稳定传输46种模式且全部模式纯度可高达98.8%及以上,其中83.3%的模式能够达到99%纯度及以上。不仅达到大容量通信的标准,也满足长距离传输的要求。对其性能进行分析,得出其具有较大的有效光纤面积,所有模式都在7.4×10-11 m2以上。并且拥有较小的非线性系数,全部模式均在1.8×10-3以下,从而保证了其功率传输能力和较稳定的传输性能。数值孔径最大可达0.1180,有着较好的收集光的能力。OAM作为新兴技术,在未来拥有无限可能,本文所设计的PCF在各项参数中都有一定的突破。结构易制作,材料易获取,使其有应用于未来光纤通信中的可能。

Abstract:

With the continuous development of optical communication and the iteration of technology, the capacity and performance of traditional optical fibers are far from meeting people"s communication needs, and improving the system capacity and performance indicators of optical communication is still an urgent and important research content. Therefore, it is extremely important to design an optical fiber that can transmit large-capacity communications. Orbital angular momentum (OAM) stands out due to its theoretical infinite capacity and excellent performance, and in order to break through the capacity limit of traditional optical fibers, photonic crystal fibers (PCFs) stand out due to their changeable structure and flexible material selection, and have attracted wide attention from the scientific research community. Based on OAM technology, a new type of PCF is designed and studied, and the finite element method is used to simulate the PCF involved. According to the simulation experiments, the new PCF can stably transmit up to 46 modes in the wavelength range of 1300-1700 nm, and the purity of all modes can be as high as 98.8% or above, of which 83.3% of the modes can reach 99% purity and above. It not only meets the standard of large-capacity communication, but also meets the requirements of long-distance transmission. The analysis of its performance shows that it has a large effective fiber area, and all modes are above 7.4×10-11 m2. And it has a small nonlinear coefficient, and all modes are below 1.8×10-3, so as to ensure its power transmission capacity and more stable transmission performance. The numerical aperture can reach up to 0.1180, which has a good ability to collect light. As an emerging technology, OAM has infinite possibilities in the future, and the PCF designed in this paper has certain breakthroughs in various parameters. The structure is easy to fabricate and the materials are easy to obtain, making it possible to be used in future optical fiber communications.