Levy's distributions of local fields intensities in metal-dielectric systems

Levy's distributions are involved in many physical phenomena. Their main ch aracteristics are a very wide spreading and a long tail. The aim of our stu dy is to use these Levy's distributions to understand optical measurements on metal-dielectric systems. Giant fluctuations of the local electric field intensity in metal-dielectric granular films in visible and infrared range have been recently studied. By using previously developed methods, we calc ulate the intensities of the local fields at each point of the sample surfa ce for Au/TiO2 cermets. We study the field intensities distributions, which show up non-negligible height in giant field values. We interpret these di stributions in terms of Levy's law. In such cases, because of the long tail decay, the most important characteristic is the decisive participation of rare events. We then conclude that high-intensities values are high enough to govern the statistical properties when the metal concentration is around 10%. (C) 2000 Elsevier Science B.V. All rights reserved.