[1] [1] B. Ferguson and X. C. Zhang, Review Article, Nature Materials 1, 26 (2002).

[2] [2] D. M. Mittleman, M. Gupta, R. Neelamani, R. G. Baraniuk, J. V. Rudd, and M. Koch, Applied Physics B: Lasers and Optics 68, 1085 (1999).

[3] [3] X. C. Zhang, Physics in Medicine and Biology 47, 1 (2002).

[4] [4] J. Jahns and S. J. Walker, Appl. Opt. 29, 931 (1990).

[5] [5] A. Glagolewa-Arkadiewa, Nature 113, 640 (1924).

[6] [6] R. Huber, F. Tauser, A. Brodschelm, M. Bichler, G. Abstreiter, and A. Leitenstorfer, Nature 414, 286 (2001).

[7] [7] S. Wang, T. Yuan, E. D. Walsby, R. J. Blaikie, S. M. Durbin, D. R. S. Cumming, J. Xu, and X. C. Zhang, Opt. Lett. 27, 1183 (2002).

[8] [8] B. E. A. Saleh and M. C. Teich, Fundamentals of Photonics, (John Wiley & Sons, Inc., New York, 1991), p.93.

[9] [9] B. Ferguson, S. H. Wang, D. Gray, D. Abbott, and X. C. Zhang, Opt. Lett. 27, 1312 (2002).

[10] [10] Q. Chen and X. C. Zhang, in Ultrafast Lasers: Technology and Applications, Fermann, Galvanauskas, and Sucha ed. (Marcel Dekker, Inc., New York, 2002), p.521.

[11] [11] I. V. Minin and O. V. Minin, Proc. SPIE 4129, 616 (2000).