[1] M. Born and E. Wolf, Principles of Optics (6th edn.) (Pergamon, Oxford, 1980) Chap.3.

[2] H. F. Arnoldus and J. T. Foley, Opt. Commun. 231, 115 (2004).

[3] H. F. Arnoldus, Opt. Commun. 252, 253 (2005).

[4] W. Braunbek and G. Laukien, Optik (in German) 9, 174 (1952).

[5] H. F. Schouten, T. D. Visser, G. Gbur, D. Lenstra, and H. Blok, Opt. Express 11, 371 (2003).

[6] H. F. Schouten, T. D. Visser, D. Lenstra, and H. Blok, Phys. Rev. E 67, 036608 (2003).

[7] M. Vasnetsov and K. Staliunas, (eds.) Optical Vortices, Horizons in World Physics, Vol.228 (Nova Science, New York, 1999).

[8] A. V. Volyar, V. G. Shvedov, and T. A. Fadeeva, Opt. Spectrosc. 90, 93 (2001).

[9] V. A. Pas’ko, M. S. Soskin, and M. V. Vasnetsov, Opt. Commun. 198, 49 (2001).

[10] K. G. Lee, H. W. Kihm, J. E. Kihm, W. J. Choi, H. Kim, C. Ropers, D. J. Park, Y. C. Yoon, S. B. Choi, D. H. Woo, J. Kim, B. Lee, Q. H. Park, C. Lienau, and D. S. Kim, Nature Photon. 1, 53 (2007).

[11] Y. Ohdaira, T. Inoue, H. Hori, and K. Kitahara, Opt. Express 16, 2915 (2008).

[12] I. V. Lindell, Methods for Electromagnetic Field Analysis (Oxford University Press, Oxford, 1992) sec.1.4.

[13] J. D. Jackson, Classical Electrodynamics (3rd edn.) (Wiley, New York, 1999) p.411.