Realization of complementary medium using photonic crystals

Ever since the introduction of metamaterials, intriguing applications have been proposed by metamaterial designs. An e = μ = −1 slab will serve as a super lens to break diffraction limit. This slab, whose permittivity and permeability is with the same magnitude but of different sign to air, is the complementary medium to air. Lai et al. proposed the possibility to remote cloaking using complementary medium. However, the metamaterial design to have complementary medium realized is complicated and there are experimental demonstrations are limited. Conical dispersion can exist at the Brillouin zone center of two-dimensional photonic crystals and this dielectric photonic crystal can be regarded has an effective zero permittivity and permeability at the Dirac frequency. Close to the Dirac frequency, effective permittivity and permeability are linear to frequencies. Moreover, because of the scaling property of Maxwell's Equation, if the linear dimensions of the structures in a given dielectric PC are scaled uniformly by a factor of α, the frequency ω and wave vector k should also be scaled according to the relations ω = ω/α and k = k/α [1]. Thus a complementary medium can be realized by stacking two photonic crystal slabs scaled uniformly. Our simulations and microwave experiments give a direct demonstration of the phase compensation effect of the complementary medium. Vortex interface states in complementary medium are experimentally observed and one dimensional remote cloaking is proposed.