[1] D. J. Cook, R. M. Hochstrasser. Intense terahertz pulses by four-wave rectification in air. Opt. Lett., 25, 1210-1212(2000).

[2] V. A. Andreeva, O. G. Kosareva, N. A. Panov, D. E. Shipilo, P. M. Solyankin, M. N. Esaulkov, P. G. de Alaiza Martnez, A. P. Shkurinov, V. A. Makarov, L. Bergé, S. L. Chin. Ultrabroad terahertz spectrum generation from an air-based filament plasma. Phys. Rev. Lett., 116, 063902(2016).

[3] L.-L. Zhang, W.-M. Wang, T. Wu, R. Zhang, S.-J. Zhang, C.-L. Zhang, Y. Zhang, Z.-M. Sheng, X.-C. Zhang. Observation of terahertz radiation via the two-color laser scheme with uncommon frequency ratios. Phys. Rev. Lett., 119, 235001(2017).

[4] K. Y. Kim, J. H. Glownia, A. J. Taylor, G. Rodriguez. Terahertz emission from ultrafast ionizing air in symmetry-broken laser fields. Opt. Express, 15, 4577-4584(2007).

[5] K. Y. Kim, A. J. Taylor, J. H. Glownia, G. Rodriguez. Coherent control of terahertz supercontinuum generation in ultrafast laser-gas interactions. Nat. Photonics, 2, 605-609(2008).

[6] Z. Zhang, Y. Chen, M. Chen, Z. Zhang, J. Yu, Z. Sheng, J. Zhang. Controllable terahertz radiation from a linear-dipole array formed by a two-color laser filament in air. Phys. Rev. Lett., 117, 243901(2016).

[7] Z. Zhang, Y. Chen, S. Cui, F. He, M. Chen, Z. Zhang, J. Yu, L. Chen, Z. Sheng, J. Zhang. Manipulation of polarizations for broadband terahertz waves emitted from laser plasma filaments. Nat. Photonics, 12, 554-559(2018).

[8] A. Nguyen, P. G. de Alaiza Martínez, J. Déchard, I. Thiele, I. Babushkin, S. Skupin, L. Bergé. Spectral dynamics of THz pulses generated by two-color laser filaments in air: the role of Kerr nonlinearities and pump wavelength. Opt. Express, 25, 4720-4740(2017).

[9] A. Nguyen, P. G. de Alaiza Martnez, I. Thiele, S. Skupin, L. Bergé. THz field engineering in two-color femtosecond filaments using chirped and delayed laser pulses. New J. Phys., 20, 033026(2018).

[10] N. Karpowicz, X.-C. Zhang. Coherent terahertz echo of tunnel ionization in gases. Phys. Rev. Lett., 102, 093001(2009).

[11] D. Zhang, Z. Lü, C. Meng, X. Du, Z. Zhou, Z. Zhao, J. Yuan. Synchronizing terahertz wave generation with attosecond bursts. Phys. Rev. Lett., 109, 243002(2012).

[12] V. A. Kostin, I. D. Laryushin, A. A. Silaev, N. V. Vvedenskii. Ionization-induced multiwave mixing: terahertz generation with two-color laser pulses of various frequency ratios. Phys. Rev. Lett., 117, 035003(2016).

[13] C. Köhler, R. Guichard, E. Lorin, S. Chelkowski, A. D. Bandrauk, L. Bergé, S. Skupin. Saturation of the nonlinear refractive index in atomic gases. Phys. Rev. A, 87, 043811(2013).

[14] Z. Zhou, D. Zhang, Z. Zhao, J. Yuan. Terahertz emission of atoms driven by ultrashort laser pulses. Phys. Rev. A, 79, 063413(2009).

[15] T. Balčiūnas, D. Lorenc, M. Ivanov, O. Smirnova, A. M. Zheltikov, D. Dietze, K. Unterrainer, T. Rathje, G. G. Paulus, A. Baltuška, S. Haessler. CEP-stable tunable THz-emission originating from laser-waveform-controlled sub-cycle plasma-electron bursts. Opt. Express, 23, 15278-15289(2015).

[16] H. Hamster, A. Sullivan, S. Gordon, W. White, R. W. Falcone. Subpicosecond, electromagnetic pulses from intense laser-plasma interaction. Phys. Rev. Lett., 71, 2725-2728(1993).

[17] I. Babushkin, A. J. Galan, V. Vaičaitis, A. Husakou, F. Morales, A. Demircan, J. R. C. Andrade, U. Morgner, M. Ivanov. All-optical attoclock: accessing exahertz dynamics of optical tunnelling through terahertz emission(2018).

[18] W. Becker, A. Lohr, M. Kleber, M. Lewenstein. A unified theory of high-harmonic generation: application to polarization properties of the harmonics. Phys. Rev. A, 56, 645-656(1997).

[19] Y. Zhang, Y. Chen, S. Xu, H. Lian, M. Wang, W. Liu, S. L. Chin, G. Mu. Portraying polarization state of terahertz pulse generated by a two-color laser field in air. Opt. Lett., 34, 2841-2843(2009).

[20] W. Chen, Y. Huang, C. Meng, J. Liu, Z. Zhou, D. Zhang, J. Yuan, Z. Zhao. Theoretical study of terahertz generation from atoms and aligned molecules driven by two-color laser fields. Phys. Rev. A, 92, 033410(2015).

[21] M. Ammosov, N. Delone, V. Krainov. Tunnel ionization of complex atoms and of atomic ions in an alternating electromagnetic field. JETP, 64, 1191-1194(1986).

[22] X. Xie, J. Dai, X.-C. Zhang. Coherent control of THz wave generation in ambient air. Phys. Rev. Lett., 96, 075005(2006).

[23] P. Planken, H. Nienhuys, H. Bakker. Measurement and calculation of the orientation dependence of terahertz pulse detection in ZnTe. J. Opt. Soc. Am. B, 18, 313-317(2001).