Abstract
A brief and self-consistent presentation for the integration of the Maxwell equations is present to study dielectric and magnetic dispersive materials using the Finite Difference Time-Domain technique. The methodology is based on a direct application of the Fourier Transform of the constitutive relations using complex variable. We study Drude and Lorentz dispersive media. We present results for the light reflection of a pulse impinging metamaterials where ε(ω) and μ(ω) are both dispersive.