Modulation of two-color laser-induced filament terahertz emission by effective length variation P.A. Chizhov, A.A. Ushakov, V.V. Bukin and S.V. Garnov EPJ Web Conf., 195 (2018) 03003 Published online: 23 November 2018 DOI: 10.1051/epjconf/201819503003