Reducing light scattering of multilayer dielectric high-reflection coatings through film system optimization design

Abstract Light scattering of high reflection (HR) coatings caused by interface roughness can be a critical factor for their practical application. A new optimal design method is proposed to reduce the scattering losses of high-reflection coatings by optimizing the interfacial electric field intensity distribution without changing the spectral reflectance of the coatings. Three kinds of high-reflection coatings with different structures are obtained, namely, standard stack high-reflection coatings, standard stacked with additional high refractive index top layer high-reflection coating and standard stack with modified top layers high-reflection coating. The distributions of electric field intensity of three kinds of high-reflection coatings are analyzed and the angle resolved scattering (ARS) of three kinds of high-reflection coatings are simulated under fully uncorrelated interfaces roughness model. Theoretical simulation and experimental results show that the scattering loss of high-reflection coatings can be effectively reduced by optimizing the design of high-reflection coatings to reduce the distribution of electric field intensity.