Metamaterial slab excited by an arbitrarily oriented dipole

A double negative metamaterial slab with material parameters perturbed from the ideal case ε_r = μ_r = -1 and excited by an arbitrarily oriented Hertzian dipole is considered. An arbitrarily oriented dipole excites both TE and TM modes, and depending on the degree of perturbation of the material constants the modes are transmitted unequally through the slab. Approximations in the electrostatic limit fail to predict this phenomenon. A tool for evaluating the field intensities in the focal region is developed and the imaging characteristics of the slab are investigated in the spectral domain. Differences between two types of excitation are pointed out and the effect of perturbations in the slab material on the field distribution in the focal plane is discussed.