Investigation of quasi-steady-state self-focusing in nonlinear left-handed metamaterials

We investigate quasi-steady-state (QSS) self-focusing in nonlinear left-handed metamaterials (NL-LHMs) theoretically. We have found that the negative refraction property of LHMs leads to the fact that the changes of the self-focusing distance and the focus appearing time with the spatial-focusing property of the input pulse are contrary to their counterparts for a conventional self-focusing medium. It is further shown that, as the convergence of the input pulse decreases, the first focus appears earlier and corresponds to smaller self-focusing distances, and that the focus moves more slowly at the smallest self-focusing distance, indicating a relatively higher risk of optical damage formation, in sharp contrast with a conventional self-focusing case. Besides, the divergent incidence cases have finite focus moving ranges. (C) 2009 Optical Society of America