[1] W. M. Steen and M. Eboo, Metal Construction 11, 332 (1979).

[2] M. El Rayes, C. Walz, and G. Sepold, Welding Journal 83, (Suppl.) 147 (2004).

[3] H. Staufer, Welding in the World 49, 66 (2005).

[4] D. P. Pace, K. L. Kenney, and D. L. Galiher, in Proceedings of the ASM International Conference: 6th International Trends in Welding Research 442 (2002).

[5] C. V. Hyatt, K. H. Magee, J. F. Porter, V. E. Merchant, and J. R. Matthews, Welding Research 80, (Suppl.) 163 (2001).

[6] T. Ueyama, H. Tong, I. Yazawa, M. Hirami, K. Nakata, and M. Ushio, Welding in the World 48, 139 (2004).

[7] Y. Chen, Z. Lei, L. Li, and L. Wu, Chin. Opt. Lett. 4, 33 (2006).

[8] T. Graf and H. Staufer, Welding Journal 82, 42 (2003).

[9] U. Jasnau, J. Hoffmann, and P. Seyffarth, in Proceedings of the International Conference on Robotic Welding, Intelligence and Automation pp.14-24 (2004).

[10] J. Paulin and G. Simon, J. Phys. D: Appl. Phys. 26, 1523 (1993).

[11] C. E. Albright, J. Eastman, and W. Lempert, Welding Journal 80, 55 (2001).

[12] B. Hu and G. den Ouden, Science and Technology of Welding and Joining 10, 427 (2005).

[13] B. Hu and G. den Ouden, Science and Technology of Welding and Joining 10, 76 (2005).

[14] B. W. Shinn, D. F. Farson, and P. E. Denney, Science and Technology of Welding and Joining 10, 475 (2005).

[15] N. Abe, Y. Kunugita, M. Hayashi, and Y. Tsuchitani, in Proceedings of Section G-ICALEO of Laser Institute of America 83, 155 (1997).

[16] M. Kutsuna and L. Chen, Proc. SPIE 4831, 341 (2003).