[1] [1] R. Szipocs, K. Ferencz, C. Spielmann, and F. Krausz, Opt. Lett. 19, 201 (1994).

[2] [2] R. Szipocs, A. Kohazi-Kis, S. Lako, P. Apai, A. P. Kovacs, G. DeBell, L. Mott, A. W. Louderback, A. V. Tikhonravov, and M. K. Trubetskov, Appl. Phys. B 70, S51 (2000).

[3] [3] M. Gerken and D. A. B. Miller, Appl. Opt. 42, 1330 (2003).

[4] [4] H. G. Winful, New. J. Phys. 8, 101 (2006).

[5] [5] D. I. Babic and S. W. Corzine, IEEE J. Quantum Electron. 28, 514 (1992).

[6] [6] K. Ferencz and R. Szipocs, Opt. Eng. 32, 2525 (1993).

[7] [7] E. J. Mayer, J. Mobius, A. Euteneuer, W. W. Ruhle, and R. Szipocs, Opt. Lett. 22, 528 (1997).

[8] [8] V. Pervak, C. Teisset, A. Sugita, S. Naumov, F. Krausz, and A. Apolonski, Opt. Express 16, 10220 (2008).

[9] [9] B. C. Stuart, M. D. Feit, S. Herman, A. M. Rubenchik, B. W. Shore, and M. D. Perry, Phys. Rev. B 53, 1749 (1996).

[10] [10] MATLAB Curve Fitting Toolbox documentation, http://www.mathworks.com/help/toolbox/curvefit/.