title: Backward terahertz radiation from intense laser-solid interactions.
abstract: We report a systematic study on backward terahertz (THz) radiation generation from laser-solid interactions by changing a variety of laser/plasma parameters. We demonstrate a high-energy (with an energy flux density reaching 80 μJ/sr), broadband (>10 THz) plasma-based radiation source. The radiation energy is mainly distributed either in the >10 THz or <3 THz regions. A radial surface current formed by the lateral transport of low-energy electrons (LEE) is believed to be responsible for the radiation in the high-THz region (>10 THz), while high-energy surface fast electrons (SFE) accelerated along the target surface mainly contribute to lower frequency (<3 THz) radiation. The unifying explanation could be applied to backward THz radiation generation from solid targets with presence of relative small preplasmas.
authors.forename: Chun
authors.initials: C
authors.lastname: Li
authors.forename: Guo-Qian
authors.initials: GQ
authors.lastname: Liao
authors.forename: Mu-Lin
authors.initials: ML
authors.lastname: Zhou
authors.forename: Fei
authors.initials: F
authors.lastname: Du
authors.forename: Jing-Long
authors.initials: JL
authors.lastname: Ma
authors.forename: Yu-Tong
authors.initials: YT
authors.lastname: Li
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Wang
authors.forename: Zheng-Ming
authors.initials: ZM
authors.lastname: Sheng
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Chen
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang