title: Phase characterization in broadband THz wave detection through field-induced second harmonic generation.
abstract: We present a theoretical and experimental investigation of the THz pulse phase measured by a broadband heterodyne detection method via field-induced second-harmonic generation in ambient air. The dependence of the detected THz phase spectra on the positions of the wire shaped electrodes scanning along the detection plasma is discussed. An additional phase shift around the beam focus is observed. Theoretical deductions reveal that it is caused by the Gouy shift of the optical probe beam and THz beam during the heterodyne detection process.
authors.affiliation: Beijing Key Lab for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, No.105 XiSanHuan BeiLu, Beijing, 100048, China. zhlliang@126.com
authors.forename: Liangliang
authors.initials: L
authors.lastname: Zhang
authors.forename: Hua
authors.initials: H
authors.lastname: Zhong
authors.forename: Kaijun
authors.initials: K
authors.lastname: Mu
authors.forename: Cunlin
authors.initials: C
authors.lastname: Zhang
authors.forename: Yuejin
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D003198:Computer Simulation; D008027:Light; D008962:Models, Theoretical; D010783:Photometry / Q000379:methods*; D012542:Scattering, Radiation; D055053:Terahertz Radiation