Zhang Xiangdong
Department of Physics, Beijing Normal University, China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Mar;71(3 Pt 2B):037601. doi: 10.1103/PhysRevE.71.037601. Epub 2005 Mar 16.
It has been suggested that a subwavelength image can be realized by a photonic crystal slab with a square lattice in the lowest band. However, due to the anisotropy of dispersion in such a photonic structure, the image only appears in the near-field region. In this paper, we show that subwavelength far-field focusing and imaging, explicitly following the well-known wave-beam negative refraction law with relative refractive index of -1, can also be realized by a square photonic crystal through choosing suitable scatterers for the lowest valence band.
