[1] [1] Kaplan A E. Diffraction-induced transformation of near-cycle and subcycle pulses. J. Opt. Soc. Am. (B), 1998, 15(3):951～955

[2] [2] Ranka J K, Ranka A L. Breakdown of the slowly varying envelope approximation in the self-focusing of ultrashort pulses. Opt. Lett., 1998, 23(7): 534～536

[3] [3] Brabec T, Krausz F. Nonlinear optics pulse propagation in the single-cycle regime. Phys. Rev. Lett., 1997, 78(17): 3282～3285

[4] [4] Caron C F R, Potvliege R M. Free-space propagation of ultrashort pulses: space-time couplings in Gaussian pulse beams. J. Modern Optics, 1999, 46(13): 1881～1891

[5] [5] Feng S, Winful H G. Guoy shift and temporal reshaping of focused single-cycle electromagnetic pulses. Opt. Lett., 1998, 23(5): 385～387

[6] [6] Feng S, Winful H G. Spatiotemporal structure of isodiffracting ultrashort electromagnetic pulses. Phys. Rev. (E), 2000, 61(1): 862～873

[7] [7] Wang Zhongyang, Zhang Zhengquan, Xu Zhizhan et al.. Space-time profiles of an ultrashort pulsed Gaussian beam. IEEE J. Quant. Electron., 1997, 33(4): 566～573

[8] [8] Wang Zhongyang, Xu Zhizhan, Zhang Zhengquan. Diffraction integral formulas of the pulsed wave field in the temporal domain. Opt. Lett., 1997, 22(6): 354～356

[9] [9] Porras M A. Nonsinusoidal few-cycle pulsed light beams in free space. J. Opt. Soc. Am. (B), 1999, 16(9): 1468～1474

[10] [10] Porras M A. Ultrashort pulsed Gaussian light beams. Phys. Rev. (E), 1998, 58(1): 1086～1093

[18] [18] Born M, Wolf E. Principles of Optics. 7th ed. Cambridge: Cambridge University Pres, 1999. 557～562