Imaging properties of triangular lattice photonic crystal at multi-bands

The propagation of electromagnetic (EM) waves in two-dimensional triangular-lattice photonic crystals (PCs) is investigated through dispersion characteristics analysis and numerical simulation of field pattern. The designed PC structure can exhibit all angle negative refraction in the second and the eighth band. A flat superlen formed from such a PC has been designed and its imaging properties have been investigated systematically. Both in band 2 and band 8, a quite high quality image in the opposite side of the slab can be found.