Tailoring OAM spectrum of high-order harmonic generation driven by two mixed Laguerre–Gaussian beams with nonzero radial nodes  

作　　者：汪倍羽 韩嘉鑫 金成 Beiyu Wang;Jiaxin Han;Cheng Jin(Department of Applied Physics,Nanjing University of Science and Technology,Nanjing 210094,China;MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials,South China Academy of Advanced Optoelectronics,South China Normal University,Guangzhou 510006,China [2]Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China

出　　处：《Chinese Physics B》2023年第12期80-89,共10页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos.12274230,91950102,and 11834004);the Funding of Nanjing University of Science and Technology (Grant No.TSXK2022D005)。

摘　　要：The extreme ultraviolet(XUV)light beam carrying orbital angular momentum(OAM)can be produced via high-order harmonic generation(HHG)due to the interaction of an intense vortex infrared laser and a gas medium.Here we show that the OAM spectrum of vortex HHG can be readily tailored by varying the radial node(from 0 to 2)in the driving laser consisting of two mixed Laguerre-Gaussian(LG)beams.We find that due to the change in spatial profile of HHG,the distribution range of the OAM spectrum can be broadened and its shape can be modified by increasing the radial node.We also show that the OAM mode range becomes much wider and its distribution shape becomes more symmetric when the harmonic order is increased from the plateau to the cutoff when the driving laser has the nonzero radial nodes.Through the map of coherence length and the evolution of harmonic field in the medium,we reveal that the favorable off-axis phase-matching conditions are greatly modified due to the change of intensity and phase distributions of driving laser with the radial node.We anticipate this work to stimulate some interests in generating the XUV vortex beam with tunable OAM spectrum through the gaseous HHG process achieved by manipulating the mode properties of the driving laser beam.

关 键 词：orbital angular momentum(OAM)spectrum high-order harmonic generation Laguerre–Gaussian beam radial nodes PHASE-MATCHING 

分 类 号：TN248[电子电信—物理电子学]