The optimization of solar blind UV high reflectance coatings

Abstract

Ultraviolet (UV) communication is a new kind of communication method by realizing non line-of-sight transmission of information, which overcomes disadvantages of line-of sight communication in other free space optical communication, such as non-UV laser communication. It will have a bright prospect of application. At present, there are more and more studies on UV communication technology at home and abroad. As for the UV communication system of our studies, we have researched deeply on one of the key technologies of UV communication that is UV high reflectance coatings. Based on the traditional theories and arithmetic of design for quarter-wavelength multilayer high reflectance coatings, the Needle method is improved greatly for the coating design, thus a kind of solar blind UV high reflectance coatings is designed. Results of calculation shows that this solar blind UV high-reflecting coating's reflectance is more than 97% at the range of wavelength λ=250~280nm and the coating's reflectance is smaller than 3% at the range of wavelength λ>300nm. Compared with Al coating and quarter- wavelength high reflective multi-layers coating, the coating is more suitable to be used in the atmosphere UV communication system, so the communication distance and the sensitivity of receiving system can be improved greatly. This solar blind UV high-reflecting coating can also be used in other UV optical technology and application, such as UV image, UV reconnaissance.