摘要
利用改进的马赫-曾德尔干涉仪测量了拉盖尔-高斯(LG)光束的轨道角动量(OAM)[拓扑电荷(TC)的值和符号]。模拟结果与实验结果一致。当LG光束与高斯光束发生干涉时,可以观察到类似漩涡的“花瓣”图案。“花瓣”的数量等于LG光束的TC的绝对值,干涉图样的旋转方向与TC符号有关:在TC符号为正时,干涉图样显示顺时针旋转;而在TC符号为负时,干涉图样显示逆时针旋转。只有当LG光束的光斑尺寸小于高斯光束的光斑尺寸时,才能根据干涉图样准确确定OAM状态。当LG光束的光斑尺寸接近高斯光束时,干涉图样只反映TC值,无法识别TC的符号。与传统干涉仪相比,该干涉仪可以获得稳定的干涉图样,并直接获得LG光束的OAM状态。实验现象是明显的。该研究结果为LG光束与高斯光束干涉的理论分析提供了参考,为光与物质之间的自旋-轨道相互作用奠定了研究基础。
In this study,a modified MachZehnder(MZ)interferometer is used to measure the orbital angular momentum(OAM)[the value and sign of topological charge(TC)]of a LaguerreGaussian(LG)beam.Simulated results are found to be consistent with the experimental results.Vortexlike petal patterns are observed when the LG beam interferes with the Gaussian beam.The number of petals is found to be equal to the absolute TC value of the LG beam,and the rotational direction of the interference patterns is related to the TC sign:at a positive TC value,the interference patterns show a clockwise rotation,whereas at a negative TC value,the interference patterns show a counterclockwise rotation.The OAM state can be accurately determined based on the interference patterns only when the spot size of the LG beam is smaller than that of the Gaussian beam.W hen the spot size of the LG beam is close to that of the Gaussian beam,the interference patterns reflect only the TC value and the TC sign cannot be identified.Compared with the conventional interferometers,the proposed interferometer can obtain a stable interference pattern and directly obtain the OAM state of the LG beam.The experimental phenomenon is obvious.The findings of this study provide a reference for the theoretical analysis of the interference between the LG and Gaussian beams and establish a research foundation for the spinorbit interaction between light and matter.
作者
于淼
王雅秋
张鹤
张云
刘璠
林爽
常明莹
葛婷
姜远飞
陈安民
李苏宇
金明星
Yu Miao;Wang Yaqiu;Zhang He;Zhang Yun;Liu Fan;Lin Shuang;Chang Mingying;Ge Ting;Jiang Yuanfei;Chen Anmin;Li Suyu;Jin Mingxing(Institute of Atomic and Molecular Physics,Jilin University,Changchun 130012,Jilin,China;Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy,Jilin University,Changchun 130012,Jilin,China)
出处
《激光与光电子学进展》
CSCD
北大核心
2022年第17期77-83,共7页
Laser & Optoelectronics Progress
基金
国家重点基础研究发展计划(2019YFA0307701)、国家自然科学基金(11704145,11974138)、吉林省教育厅“十三五”科学研究规划项目(JJKH20190181KJ)。
关键词
衍射与光栅
涡旋光束
轨道角动量
马赫-曾德尔干涉仪
diffraction and grating
vortex beam
orbital angular momentum
MachZehnder interferometer
