The spatial energy distribution and the spectrum characteristics in a two-dimensional random medium

Abstract

The spatial distributions of energy in a random medium and the spectrum characteristics of some regions in this medium are studied and the results show that the energy is localized in some regions and the spatial distribution of the energy is both related with positions of the particles in the medium and the wavelength of excitation light. And the regions of energy congregation are related with the quasi-closed structures formed from the particles but no one to one correspondence exists between them. Under the stimulating of the same excitation light, different spectra appear in different quasi-closed structures and they change with time. And under the stimulating of different excitation light sources, the spectra of the same quasi-closed structure are different. When the wavelength of exci tation light does not match the configuration parameter of a quasi-closed structure, the peaks of its spectrum will change frequently and the energies of the peaks are attenuated quickly. When the wavelength of the light be ther matches the configuration parameter of the quasi-closed structure, a certain peak will retain its leading position in height in the spectrums and its energy attenuate but slowly. So photon-localization is both related with the configuration of medium and the wavelength of excitation light, and the random lasing can be regarded as the result of the general scattering effect of the excitation light by the random medium.