Two-dimensional absolute photonic band gaps in the visible

The most promising two-dimensional photonic crystals are the graphite latti ce of dielectric rods in air background and the triangular lattice of air h oles in dielectric background. In this paper, we compare their convenience in achieving structures which inhibit the propagation of visible electromag netic waves. For visible waves, etching is difficult because the structure period must be smaller than the light wavelength. Furthermore, the semicond uctor materials whose electronic band gap does not absorb any optical waves have little dielectric constant, which reduces photonic band gap widths. W e show, using the Plane wave Method and the Transfer Matrix Method, that th e triangular structure is not appropriate because its gap is too narrow and its dimensions are too small for fabrication. On the other hand, wider gap s and larger dimensions that should be etched easily in wide gap semiconduc tors make graphite a much more suitable structure. (C) 1999 Academic Press.