title: Waveform-controlled terahertz radiation from the air filament produced by few-cycle laser pulses.
abstract: Waveform-controlled terahertz (THz) radiation is of great importance due to its potential application in THz sensing and coherent control of quantum systems. We demonstrated a novel scheme to generate waveform-controlled THz radiation from air plasma produced when carrier-envelope-phase (CEP) stabilized few-cycle laser pulses undergo filamentation in ambient air. We launched CEP-stabilized 10 fs-long (~1.7 optical cycles) laser pulses at 1.8 μm into air and found that the generated THz waveform can be controlled by varying the filament length and the CEP of driving laser pulses. Calculations using the photocurrent model and including the propagation effects well reproduce the experimental results, and the origins of various phase shifts in the filament are elucidated.
authors.affiliation: State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Bai
authors.forename: Liwei
authors.initials: L
authors.lastname: Song
authors.forename: Rongjie
authors.initials: R
authors.lastname: Xu
authors.forename: Chuang
authors.initials: C
authors.lastname: Li
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.forename: Zhinan
authors.initials: Z
authors.lastname: Zeng
authors.forename: Zongxin
authors.initials: Z
authors.lastname: Zhang
authors.forename: Haihe
authors.initials: H
authors.lastname: Lu
authors.forename: Ruxin
authors.initials: R
authors.lastname: Li
authors.forename: Zhizhan
authors.initials: Z
authors.lastname: Xu