MIXING FORMULAS IN THE TIME-DOMAIN

The dispersive properties of dielectric materials in both the time and the frequency domains are discussed. Special emphasis is placed on th e treatment of heterogeneous materials, particularly two-phase mixture s. A time-domain Maxwell-Garnett rule is derived that differs from the corresponding frequency-domain formula in that it is expressed in ter ms of convolutions and inverse operators of the susceptibility kernels of the materials. Much of the analysis deals with the question of how the temporal dispersion of the dielectric responses of various physic al materials is effected by the mixing process. Debye, Lorentz, Drude, and modified Debye suseptibility models are treated in detail. (C) 19 98 Optical Society of America.