[1] C. Yang and J. Mertz, Opt. Lett. 28, 224 (2002).
[2] T. Pons and J. Mertz, J. Opt. Soc. Am. B 21, 1486 (2004).
[3] M. Quinten, Appl. Phys. B 73, 245 (2001).
[4] C. Wu, C. H. Crouch, L. Zhao, and E. Mazur, Appl. Phys. Lett. 81, 1999 (2002).
[5] S. Amuroso, R. Bruzzese, N. Spinelli, R. Velotta, M. Vitiello, X. Wang, G. Ausanio, V. Iannotti, and L. Lanotte, Appl. Phys. Lett. 84, 4502 (2004).
[6] L. A. Golovan, L. P. Kuznetskova, A. B. Fedotov, S. O. Konorov, D. A. Sidorov-Biryukov, V. Y. Timoshenko, A. M. Zheltikov, and P. K. Kashkarov, Appl. Phys. B 76, 429 (2003).
[7] S. O. Konorov, A. B. Fedotov, A. A. Ivanov, M. V. Alfimov, S. V. Zabotnov, A. N. Naumov, D. A. Sidorov-Biryukov, A. A. Podshivalov, A. N. Petrov, L. Fornarini, M. Carpanese, G. Ferrante, R. Fantoni, and A. M. Zheltikov, Opt. Commun. 224, 309 (2003).
[8] G. Agrawal, Nonlinear Fiber Optics (Academic Press, New York, 2002).
[9] T. Wilson and C. J. R. Sheppard, Theory and Practice of Scanning Optical Microscopy (Academic Press, London, 1984).
[10] Y. Barad, H. Eisenberg, M. Horowitz, and Y. Silberberg, Appl. Phys. Lett. 70, 922 (1997).
[11] J. A. Squier, M. Muller, G. J. Brakenhoff, and K. Wilson, Opt. Express 3, 315 (1998).
[12] J. M. Schins, Schrama, J. Squier, G. J. Brakenhoff, and M. Muller, J. Opt. Soc. Am. B 19, 1627 (2002).
[13] R. Guenther, Modern Optics (John Wiley and Sons, New York, 1990).
[14] R. Juskaitis, "Characterizing high numerical apertures microscope objective lenses" in Optical Imaging and Microscopy, Springer Series in Optical Sciences, Torok and Kao, (eds.) Vol. 87 (Springer-Verlag, Berlin, 2003).
[15] M. Gu, Principles of Three-Dimensional Imaging in Confocal Microscopes (World Scientific, Singapore, 1996).
