基于倾斜光纤光栅的光轨道角动量操控及特性研究

Compared with intensity, wavelength, frequency, phase and polarization, orbital angular momentum (OAM) of light can be considered as a new degree of freedom, which can improve significantly the control approaches and information capacities of a single photon or light. OAM has gain many important experimental results and has wide applications in many fields such as optical tweezers, atom trapping and manipulation, quantum and classical optical communications. To solve the problem of the current OAM manipulation methods cannot integrated with the normal optical fiber communication system, in the proposal, the study of manipulation and characters of OAM in communication fiber based on tilted fiber gratings with additional birefringence is presented. The study contents include: the mode-coupled equation and mode-selection rule between the fundamental mode and OAM mode in the tilted fiber grating, the performance estimated method, the parameter design method, the grating fabrication according to its period, length, tilted angle, refractive index, the amount of additional birefringence, and the performance testing and verification. The proposal demonstrates a new OAM manipulation method which can generate arbitrary topological charge of OAM mode, and can be integrated with the normal fiber communication system conveniently. The proposal gives an additional degree of freedom for the current fiber communication system. And it then provides a new academic fundamentals and technical methods for the increasing of the information capacity and spectral efficiency of the fiber communication systems.

相对于强度、波长、频率、相位和偏振而言光轨道角动量(OAM)可作为一新的自由度，对它的合理应用将显著提升单个光子或光波的可操控性和信息容量，在原子囚禁与操控、量子和经典光通信等领域具有广泛的应用前景，已在多项重要实验中得到了初步验证。本项目针对在光纤通信中广泛应用OAM的目标，立足于解决当前OAM操控方法不便于与常规光纤通信系统集成的问题，提出利用附加双折射的倾斜光纤光栅在常规通信光纤中进行OAM的操控及特性研究。研究内容包括：建立倾斜光纤光栅中基模和OAM模式的耦合模方程及模式选择规则，并建立OAM特性的理论评估模型，然后优化设计操控OAM所需的光栅参数，并进行光栅实验制作及特性测试验证。本项目提出了一种新的OAM产生方法，能实现任意量子数OAM的产生，同时便于与常规光纤通信系统集成，从而为当前光纤通信系统提供可靠的额外自由度，为通信容量和光谱效率的进一步增加提供新的学术基础和技术手段。

相对于强度、波长、频率、相位和偏振而言光轨道角动量(OAM)可作为一新的自由度，对它的合理应用将显著提升单个光子或光波的可操控性和信息容量，在原子囚禁与操控、量子和经典光通信等领域具有广泛的应用前景，已在多项重要实验中得到了初步验证。本项目根据计划书的要求开展了光纤光栅及光轨道角动量的研究，对光轨道角动量的数理特征、干涉测量方法进行了研究，建立了倾斜光纤光栅的矢量耦合模方程，以及倾斜光纤光栅产生轨道角动量的模式选择规则，初步证实了倾斜光纤光栅用于轨道角动量产生及操控的合理性。并在研究过程中对相关的光纤光栅损耗效应、光纤光栅单频激光噪声测试、光纤光栅滤波器用于光纤时频传递等问题进行了扩展研究。项目共发表标注受本项目资助的SCI收录期刊论文 2篇、EI收录期刊论文3篇，申请中国发明专利5件，其中1件已授权，软件著作权登记1件，发表英文学术专著1章。项目培养参研青年技术骨干 3 名，协助培养博士研究生 3 名顺利毕业。