Complete photonic band gap in a two-dimensional chessboard lattice

The photonic structure of a two-dimensional square lattice with square columns rotated by 45^∘ is theoretically studied. For a range of dielectric filling factors around $f=0.5$ (for which the lattice reduces to a chessboard) a photonic band gap common to s and p polarizations is found. The complete band gap occurs for a wide range of values of the dielectric contrast and is maximum for relatively low values of the contrast.