A high contrast imaging technique based on an optical vortex coronagraph (OVC) is used to measure the spatial phase profile induced by an air plasma generated by a femtosecond laser pulse. The sensitivity of the OVC method significantly surpassed both in-line holographic and direct imaging methods based on air plasma fluorescence. The estimated phase sensitivity of 0.046 waves provides opportunities for OVC applications in areas such as bioimaging, material characterization, as well as plasma diagnostics.
@article{arxiv.2108.01606,
title = {Optical vortex coronagraph imaging of a laser-induced plasma filament},
author = {Qingqing Liang and Xia Huang and Yanfei Mou and Shaodong Zhou and Wenxing Zhang and Jieyu Gui and Grover A. Swartzlander and JR. and Qingqing Cheng and Yi Liu},
journal= {arXiv preprint arXiv:2108.01606},
year = {2021}
}