Optical properties of metal-dielectric multilayers in the near UV region

Metal-dielectric multilayers have versatile optical properties that can be used in many applications. The special properties of metal films in the near UV region are analyzed in terms of the d-band contribution to the plasma oscillation. The important parameters that determine the multilayer optical properties such as skin depth dependence on the wavelength and the thickness of silver films have been calculated. The morphology of silver films on titanium dioxide has been observed by TEM. The results indicate that an optimal thickness exists for near UV transparency, and that may be related to the resonance of voids and interface enhanced resonance-tunneling transmission of semi-continuous silver films. A special heat mirror with high transparency in the near UV region was designed and fabricated according to the optimal thickness of silver; it has been found to exhibit sound optical properties.