Anderson localization of surface plasmons and Kerr nonlinearity in semicontinuous metal films

We predict that in the optical and infrared spectral ranges the local field s in semicontinuous metal films are very inhomogeneous and consist of sharp peaks representing localized surface plasmons. The localization maps the A nderson localization problem described by the random Hamiltonian with both on- and off-diagonal disorder. The local fields exceed the applied field by several orders of magnitudes resulting in giant enhancements of various op tical phenomena including Kerr nonlinearity. The Kerr effect has characteri stic dip at the percolation threshold due to the strong dependence of the K err effect on the localization length of the surface plasmons. (C) 2000 Pub lished by Elsevier Science B.V. All rights reserved.