摘要
Vortex harmonics with fractional average orbital angular momentum are genera ted when a relativistic fractional vortex beam is incident on and reflected from an over-dense plane plasma target. A two-step model is presented to explain the far-field patterns of the harmonics. In the Erst step, a fundamental spot-shaped hole is produced during the hole-boring stage, and harmonics are genera ted simultaneously. In the second step, differen t oTder harmonics are diffracted by the hole and propagate to the far field. This process can be accurately described by the Fraunhofer diffraction theory. This work facilitates a basic recognition of fractional vortex beams.
Vortex harmonics with fractional average orbital angular momentum are generated when a relativistic fractional vortex beam is incident on and reflected from an over-dense plane plasma target. A two-step model is presented to explain the far-field patterns of the harmonics. In the first step, a fundamental spot-shaped hole is produced during the hole-boring stage, and harmonics are generated simultaneously. In the second step, different order harmonics are diffracted by the hole and propagate to the far field. This process can be accurately described by the Fraunhofer diffraction theory. This work facilitates a basic recognition of fractional vortex beams.
作者
李沙沙
沈百飞
王文鹏
步志刚
张浩
张辉
翟树华
Shasha Li;Baifei Shen;Wenpeng Wang;Zhigang Bu;Hao Zhang;Hui Zhang;Shuhua Zhai
基金
supported by the National Natural Science Foundation of China (Nos. 11575274, 11674339, and 11335013)
the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB16)
the Ministry of Science and Technology of the People’s Republic of China (Nos. 2016YFA0401102 and 2018YFA0404803)
the Innovation Program of Shanghai Municipal Education Commission
the Shanghai Supercomputer Center for their support