Probing the orbital angular momentum of intense vortex pulses with strong-field ionization

Yiqi Fang; Zhenning Guo; Peipei Ge; Yankun Dou; Yongkai Deng; Qihuang Gong; Yunquan Liu

doi:10.1038/s41377-022-00726-7

Probing the orbital angular momentum of intense vortex pulses with strong-field ionization

Light Sci Appl. 2022 Feb 8;11(1):34. doi: 10.1038/s41377-022-00726-7.

Authors

Yiqi Fang¹, Zhenning Guo¹, Peipei Ge¹, Yankun Dou¹, Yongkai Deng¹, Qihuang Gong^{1

2

3

4}, Yunquan Liu^{5

6

7

8}

Affiliations

¹ State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China.
² Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, China.
³ Center for Applied Physics and Technology, HEDPS, Peking University, Beijing, 100871, China.
⁴ Beijing Academy of Quantum Information Sciences, Beijing, 100193, China.
⁵ State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, 100871, China. Yunquan.liu@pku.edu.cn.
⁶ Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, China. Yunquan.liu@pku.edu.cn.
⁷ Center for Applied Physics and Technology, HEDPS, Peking University, Beijing, 100871, China. Yunquan.liu@pku.edu.cn.
⁸ Beijing Academy of Quantum Information Sciences, Beijing, 100193, China. Yunquan.liu@pku.edu.cn.

Abstract

With the rapid development of femtosecond lasers, the generation and application of optical vortices have been extended to the regime of intense-light-matter interaction. The characterization of the orbital angular momentum (OAM) of intense vortex pulses is very critical. Here, we propose and demonstrate a novel photoelectron-based scheme that can in situ distinguish the OAM of the focused intense femtosecond optical vortices without the modification of light helical phase. We employ two-color co-rotating intense circular fields in the strong-field photoionization experiment, in which one color light field is a plane wave serving as the probing pulses and the other one is the vortex pulses whose OAM needs to be characterized. We show that by controlling the spatial profile of the probing pulses, the OAM of the vortex pulses can be clearly identified by measuring the corresponding photoelectron momentum distributions or angle-resolved yields. This work provides a novel in situ detection scenario for the light pulse vorticity and has implications for the studies of ultrafast and intense complex light fields with optical OAM.