Study on Absolute Photonic Bandgap in Two-Dimensional Compound Lattices Photonic Crystal with Rotating Cylinders

A two-dimensional compound lattices photonic crystal with rotating cylinders is proposed.The bandgap of this structure is calculated by using plan wave expansion method.The result indicate that a large absolute bandgap of this structure can be found by optimizing the parameters,the size of absolute bandgap is 0.08538 and the ratio of the bandgap width to the centre frequency of the bandgap is 17.91%.As to other photonic crystal structure,this structure is easy to form absolute bandgap.