The photonic frequency band structure of a two-dimensional photonic crystals ofsquare lattice with rotating square cylinders

Designed a two-dimension photonic crystal of square lattice with rotating square cylinders,calculated their frequency band structures for this kind of photonic crystal and found existing a large absolute band gap in the low and high frequency regions by using the plane wave expansion method.The photonic band structure and density of state of a two-dimensional photonic crystals of square lattice with Al rotating square cylinders in air have been calculated.It exists a maximum absolute PBG for f=0.5 and when rotating angle θ= 45°,and the absolute PBG lies in the high frequency range for θ= 0°.Furthermore,the FDTD(finite-different time-domain) method was used to examining the numerical results and analyzing the waveguide characteristics and its electric field distribution of TM mode for θ= 45°.