Transmission properties of metal photonic crystal films in visible light and microwave

Abstract

The one-dimensional metallic photonic crystal film is an anisotropic metamaterial with an equivalent and uniform metal-medium multilayered structure. Compared with the single-layer metal film, the one-dimensional metal photonic crystal film has a higher degree of freedom in terms of chromatic dispersion regulation and control. With the existing of surface plasmon polariton (SPP), directional transmission of evanescent waves can be achieved. The experimental results and the calculated results of the equivalent medium theory and the finite-difference time domain (FDTD) method show that the active control on the wavelength, bandwidth and strength of the evanescent waves during transmitting can be realized by regulating the metal photonic crystal structure. The smaller is the ratio of metal film thickness, the longer are the center of the transmission wavelength and the cutoff wavelength, and the wider is the frequency band. When the thickness of the metal film layer is smaller than the penetration depth of the SPP, wide frequency-band evanescent waves can be transmitted. This paper also studied the transmission performance in the microwave band of the metal photonic crystal, finding that at the microwave band, the equivalent dielectric constant of the metal photonic crystal is negative and the metallic photonic crystal has a good reflection property. Furthermore, the shielding effectiveness of the metal photonic crystal film is far better than the electromagnetic shielding effectiveness of the ITO film with the same thickness. Even at the thickness of a few hundred of nanometers, the metallic photonic crystal film can achieve good electromagnetic shielding effectiveness. Thus, by adopting the metallic photonic crystal film, light and visual electromagnetic shielding materials with thin films can be created.