Improvement of absolute band gap properties in 2D photonic crystals con-sist of GaAs rods in air background

We numerically analyze the band gap properties of a two dimensional (2D) photonic crystal created by a square lattice of GaAs rods with different radii in air back ground by plane wave expansion method. Two cross sections for rods (circular and hexagonal) are considered and the absolute band gap width is maximized with respect to the shape, radius of rods and rotation angle of the lattice.