  We propose to use double negative (DNG) metamaterial slabs to build effective
super-absorbers and perfect nanodetectors for single divergent sources. We
demonstrate by numerical simulations that an absorbing nanoparticle properly
placed inside a DNG slab back-covered with a perfect electric conductor or
perfect magnetic conductor mirror can absorb up to 100% radiation energy of a
single dipole source placed outside the slab. Furthermore, we also show that
even the simple DNG slab without any absorbing nanoparticle could be used as a
perfect absorber for both plane and divergent beams. The proposed systems may
focus the radiation in nanoscale and thus have applications in optical
nanodevices for a variety of different purposes.
