针对传统轨道角动量(Orbital Angular Momentum,OAM)通信系统难以在视距信道受阻塞的非视距环境中正常工作以及无法有效保障多用户的服务质量(Quality of Service,QoS)需求问题,文中基于智能反射表面辅助技术将多用户的非视距信道转化...针对传统轨道角动量(Orbital Angular Momentum,OAM)通信系统难以在视距信道受阻塞的非视距环境中正常工作以及无法有效保障多用户的服务质量(Quality of Service,QoS)需求问题,文中基于智能反射表面辅助技术将多用户的非视距信道转化为等效的视距信道,并在此场景下提出基于太赫兹多用户OAM正交频分多址系统下行资源优化方法。基于双层迭代资源分配算法将非凸联合优化的求解分解成外部和内部两个优化流程,基于交替优化和凸优化理论逐一求解4个核心子问题,实现各用户QoS差异化保障下的系统容量最大化。仿真结果表明,所提方法在通信资源充足时对各用户的QoS需求保障率为100%。在反射单元数量为768时,所提系统比传统OAM系统的系统容量平均提高了19.1%,并且误码率更低。在用户数量为3、信噪比为20 dB时,相较于基于相位补偿的MU(Multiuser)-OAM系统,所提系统的误码率下降了40.5%。展开更多
In the burgeoning field of light-matter interactions,angular momentum has emerged as a pivotal factor,driving innovative research directions.This study delves into the interaction dynamics between vortex lights and an...In the burgeoning field of light-matter interactions,angular momentum has emerged as a pivotal factor,driving innovative research directions.This study delves into the interaction dynamics between vortex lights and an electromagnetically induced transparency(EIT)medium,with a primary focus on elucidating the underlying mechanism of angular momentum transfer.Through comprehensive theoretical analysis and numerical simulations,it is demonstrated that when the probe field carries orbital angular momentum(OAM),the dispersion and absorption characteristics of the EIT medium undergo periodic modulation.This modulation is intricately determined by the azimuthal phase and topological charge of the beam.Notably,the OAM in the driving field exerts no such influence on the medium’s properties.Leveraging vortex phase plates(VPPs)or spatial light modulators(SLMs)to manipulate the tunable OAM enables dynamic control over the EIT effect.This breakthrough not only deepens our understanding of light-matter interactions at the quantum level but also unlocks new avenues for high-dimensional quantum information processing and advanced optical communication technologies.展开更多
文摘In the burgeoning field of light-matter interactions,angular momentum has emerged as a pivotal factor,driving innovative research directions.This study delves into the interaction dynamics between vortex lights and an electromagnetically induced transparency(EIT)medium,with a primary focus on elucidating the underlying mechanism of angular momentum transfer.Through comprehensive theoretical analysis and numerical simulations,it is demonstrated that when the probe field carries orbital angular momentum(OAM),the dispersion and absorption characteristics of the EIT medium undergo periodic modulation.This modulation is intricately determined by the azimuthal phase and topological charge of the beam.Notably,the OAM in the driving field exerts no such influence on the medium’s properties.Leveraging vortex phase plates(VPPs)or spatial light modulators(SLMs)to manipulate the tunable OAM enables dynamic control over the EIT effect.This breakthrough not only deepens our understanding of light-matter interactions at the quantum level but also unlocks new avenues for high-dimensional quantum information processing and advanced optical communication technologies.
