拉盖尔-高斯涡旋光束在电磁诱导透明介质中的传输特性  

Propagation Properties of Laguerre-Gaussian Vortex Beams in Electromagnetically-induced-transparency Media

作　　者：王勇 武晋泽 杨旭东[1] 李晋红[1] WANG Yong;WU Jin-ze;YANG Xu-dong;LI Jin-hong(School of Applied Science,Taiyuan University of Science and Technology,Taiyuan 030024,China;School of Physics,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]太原科技大学应用科学学院,山西太原030024 [2]浙江大学物理学院,浙江杭州310027

出　　处：《量子光学学报》2022年第4期350-359,共10页Journal of Quantum Optics

基　　金：国家自然科学基金(12004334);中国博士后科学基金资助项目(2020M671686);太原科技大学科研启动基金(20212076);太原科技大学研究生优秀创新项目(XCX212103)。

摘　　要：研究了拉盖尔-高斯(Laguerre-Gaussian,LG)涡旋光束在电磁诱导透明(Electromagnetically Induced Transparency,EIT)介质中的传输演化特性。在得到EIT介质ABCD传输矩阵的基础上,利用广义惠更斯-菲涅尔原理,推导出了LG涡旋光束在EIT介质中传输时的解析表达式,并研究了光束的强度和相位演化特性,以及对拓扑荷、径向指数、相干长度等参数的依赖关系。研究表明,LG涡旋光束在EIT介质中传输时经历了周期性的聚焦和扩散。对于部分相干LG涡旋光束,较小的拓扑荷或较大的径向指数会导致相位奇点被隐藏。此外,相位奇点在传输过程中会发生分裂现象,同时产生拓扑荷相反的相位奇点。随着相干长度的增加,相位奇点的隐藏、分裂和产生现象会逐渐减弱直至消失。Electromagnetically induced transparency(EIT) is an intriguing phenomenon in quantum optics,and has a wide range of applications in the fields of quantum information processing,quantum precision metrology,etc.Recently,with the rapid development of the generation and detection of vortex beams,the combination of EIT and vortex beams offers new and novel functionalities and applications,such as EIT-based atomic compass,spatially dependent EIT,and storage,transfer,and arithmetic of orbit angular momentum of light.For these investigations and applications,the propagation and evolution of vortex beams in EIT media are of crucial importance.In this article,the propagation evolution properties of a Laguerre-Gaussian(LG) vortex beam in an EIT medium with Λ-type three-level atoms are studied.Based on the generalized Huygens-Fresnel principle and the ABCD transfer matrix of the EIT medium,the analytical expression of the LG vortex beam propagating in the EIT medium is derived.The propagation evolution of the intensity and phase of the beam and their dependences on the parameters such as the topological charge,the radial index,and the coherence length are studied.It is shown that the LG vortex beam propagating in the EIT medium experiences focusing and diverging periodically.For a partially coherent LG vortex beam,a smaller topological charge or larger radial index leads to the hiding of the phase singularity.Besides,the phase singularity splits and the phase singularities with opposite topological charges are generated during propagation.As the increasing of the coherence length of the beam,the hiding,splitting and generating of the phase singularities vanish.The results could find applications in developing new EIT-based techniques.

关 键 词：电磁诱导透明 涡旋光束 惠更斯-菲涅尔原理 相位奇点 

分 类 号：O436[机械工程—光学工程]