Nian Zhang 1,2,3,4Baoxing Xiong 1,2,3,4Xiang Zhang 1,2,3,4Xiao Yuan 1,2,3,4,*
Author Affiliations
Abstract
1 Soochow University, School of Optoelectronic Science and Engineering, Suzhou, China
2 Soochow University, Collaborative Innovation Center of Suzhou Nano Science and Technology, Suzhou, China
3 Soochow University, Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province, Suzhou, China
4 Soochow University, Key Lab of Modern Optical Technologies of Education Ministry of China, Suzhou, China
Optical orbital angular momentum (OAM) multiplexed holography has been implemented as an effective method for information encryption and storage. Multiramp helicoconical-OAM multiplexed holography is proposed and experimentally implemented. The mode selectivity of the multiramp mixed screw-edge dislocations, constant parameter K, and normalized factor are investigated, respectively, which demonstrates that those parameters can be used as additional coding degrees of freedom for holographic multiplexing. The combination of the topological charge and the other three parameters can provide a four-dimensional multiplexed holography and can enhance information capacity.
orbital angular momentum multiplexed holography multiramp helicoconical beams multiple-dimensional multiplexing information encryption Advanced Photonics Nexus
2023, 2(3): 036013
西安理工大学 自动化与信息工程学院, 陕西 西安 710048
以加载QPSK调制信号的轨道角动量(OAM)光束为传输载波, 以多个相位屏模拟大气湍流, 研究不同大气湍流强度下OAM复用态的串扰情况。通过对复用光束光强和相位研究, 得出在OAM复用态光强受到湍流影响时会发生明显的闪烁现象, 光功率分散, 相位发生旋转弯曲, 且湍流强度越大, 受到的影响越大。选用螺旋谱分析不同湍流强度下各OAM复用态之间的弥散程度, 当大气湍流强度增加时, OAM态之间的弥散程度增加, 且较强湍流会导致OAM复用态失真。同时, 考虑OAM复用态之间的模式串扰以及每路携带信息的OAM态因大气信道引起的混合噪声而造成的码间干扰, 对比研究了不同大气湍流强度下系统误码率随传输距离的变化, 结果表明: 系统误码率随传输距离的增长而增大, 强湍流之下光束误码率会随着传输距离增长到一定程度后趋于平稳, 弱湍流之下光束误码率会随着传输距离的增长而增大。
轨道角动量复用 大气湍流 螺旋谱 误码率 orbital angular momentum-multiplexed atmospheric turbulence spiral spectrum bit error rate 红外与激光工程
2018, 47(11): 1122002
南京邮电大学信号处理与传输研究院, 江苏 南京 210003
轨道角动量(Orbital angular momentum, OAM)复用通信系统性能不可避免地受到发、收两端OAM态非对齐的影响。针对OAM态复用通信, 提出了一种将多输入多输出(Multiple-input multiple-output, MIMO)均衡技术用于降低OAM系统发、收两端非对齐对系统性能带来影响的方案。所提方 案利用MIMO均衡技术纠正或部分纠正复用OAM态在发、收两端非对齐时的模间串扰。数值仿真结果表明所提方 案可有效地降低OAM非对齐通信系统模式间的串扰,提升了系统的误码率性能,在位置偏移和角度偏斜量较小 情形下,系统误码率可提升1～2个数量级。
光通信 轨道角动量复用通信 非对齐 多输入多输出均衡 误码率 optical communication orbital angular momentum multiplexed communication misalignment multiple-input multiple-output equalization bit error rate
