Abstract: A two dimensional phononic crystal with nesting complex square lattice structure was fabricated, using small columns array to replace each single column basis. The band gap structures of the phononic crystal were caculated with the plane wave expansion method. The band gap maps were introduced to illustrate the influences of the columns' array-form and total filling-fraction on the area and number of band gaps, the band gap structures of complex lattices and simple lattices were compared, which validate the feasibility that the width and number of band gaps can be increased by adjusting the small columns array in nesting complex square lattices phononic crystal.

Key words: A two dimensional phononic crystal with nesting complex square lattice structure was fabricated, using small columns array to replace each single column basis. The band gap structures of the phononic crystal were caculated with the plane wave expansion method. The band gap maps were introduced to illustrate the influences of the columns' array-form and total filling-fraction on the area and number of band gaps, the band gap structures of complex lattices and simple lattices were compared, which validate the feasibility that the width and number of band gaps can be increased by adjusting the small columns array in nesting complex square lattices phononic crystal.