[1] J. C. Knight, T. A. Birks, P. St. J. Russell, and D. M. Atkin, Opt. Lett. 21, 1547 (1996).
[2] P. Russell, Science 299, 358 (2003).
[3] T. A. Birks, J. C. Knight, and P. St. J. Russell, Opt. Lett. 22, 961 (1997).
[4] J. C. Knight, J. Arriaga, T. A. Birks, A. Ortigosa-Blanch, W. J. Wadsworth, and P. St. J. Russell, IEEE Photon. Technol. Lett. 12, 807 (2000).
[5] T. A. Birks, D. Mogilevtsev, J. C. Knight, and P. St. J. Russell, IEEE Photon. Technol. Lett. 11, 674 (1999).
[6] Y. Ni, L. Zhang, and J. Peng, Chin. Opt. Lett. 1, 385 (2003).
[7] A. Ferrando, E. Silvestre, P. Andres, J. J. Miret, and M. V. Andres, Opt. Express 9, 687 (2001).
[8] K. Saitoh, M. Koshiba, T. Hasegawa, and E. Sadaoka, Opt. Express 11, 843 (2003).
[9] G. Renversez, B. Kuhlmey, and R. McPhedran, Opt. Lett. 28, 989 (2003).
[10] J. K. Ranka, R. S. Windeler, and A. J. Stentz, Opt. Lett. 25, 25 (2000).
[11] W. J. Wadsworth, J. C. Knight, A. Ortigosa-Blanch, J. Arriaga, E. Silvestre, and P. St. J. Russell, Electron. Lett. 36, 53 (2000).
[12] Y. F. Li, B. W. Liu, Z. H. Wang, M. L. Hu, Z. Wang, and Q. Y. Wang, Chin. J. Lasers (in Chinese) (to be published).
[13] K. Kawano and T. Kitoh, Introduction to Optical Waveguide Analysis: Solving Maxwell's Equations and the Schrodinger Equation (John Wiley & Sons, New York, 2001) chap. 4.
[14] V. Finazzi, T. M. Monro, and D. J. Richardson, IEEE Photon. Technol. Lett. 15, 1246 (2003).
[15] W. H. Reeves, J. C. Knight, P. St. J. Russell, and P. J. Roberts, Opt. Express 10, 609 (2002).