Study on transmission properties of 2-D super-lattice photonic crystals

The finite difference time domain method was used to calculate the transmission characteristics of 2-D super-lattice photonic crystal formed by cylinders and elliptic rods or cylinders and composite medium rods.It is shown that the width of the band gap becomes lager and the central frequency becomes higher with increase of the sectional area of elliptical rods for the cylinder-elliptical rods super-lattice.As to the case of composite medium rods super-lattice,the thicker the nested elliptical rod,the narrower the band gap is and the lower the central frequency is when the long axis is along the direction of incident wave.However,the wider band gap appeared in the range of high frequency band and in the low frequency band the band gap vanished when the long axis direction is perpendicular to the incident wave.The study provides the theory of the manufacture of photonic crystals.