Resolution Ability and Surface Bright Spots of a Lossy Left-handed Material Slab

The imaging quality of a lossy left-handed material (LHM) slab is studied. The exact solution is obtained for the interaction of a monochromatic source with a lossy LHM slab by Fourier integrals in wave number domain. It is found that a small amount of loss may have a strong suppression of the super-resolution ability. However, the resolution of a lossy slab can still be better than a conventional lens because the evanescent wave can still be partly restored if the loss is small enough. The localized field with large amplitude (surface bright spots) near the interfaces of the slab is related to the resonance of the coupling between surface waves at the interfaces. The evanescent wave restoration and the surface bright spots are two relevant phenomena. The distance of the bright spots is close to the half of the resolution length.