Off-plane band structure for triangular and square lattice with non-zero k<sub>z</sub> component were calculated using Plane Wave
Expansion Method. Both decreasing, finally breaking down of in-plane band gaps and emerging of new off-plane band
gaps were observed with an increasing k<sub>z</sub>. K<sub>z</sub> component dependence of band gap was investigated in both triangular
and square lattice, with varied air hole radius and dielectric constant.