Research On The Design And Preparation Of New-style Coatings With Broadband Wide-angle Antireflective Property

Antireflection(AR) coating is a kind of optical coating with the ability to reduce surface reflection and increase transmittance of substrate. AR coating has an extremely important position in optical film industry, which occupies more than 70% in annual global optical film market. With the development of solar energy, optical observations, new optical systems and other optical applications, the need for a coating with broadband wide-angle antireflective property is more and more urgent, which has become a hot topic in the research field of optics. So in this paper, we aimed at the new kind of AR coating with broadband wide-angle antireflective property and carried out a series of work.First, we elaborated the history and the latest research development of AR coatings. And we carried out a deep research on the AR coating theory, design methods, preparation techniques, and summarized the development of new-style nano-structured AR coatings.Second, we studied the physical mechanism of multi-layer AR coating to demonstrate antireflective principle, summed up the theoretical calculation method of the optical properties of the multi-layer film, self-edited the multi-layer film optical properties calculation software.Third, in the multi-layer AR coating design optimization algorithm, clustering global optimization algorithms was raised to optimize film design to solve the broadband antireflection coating design problem, by careful analysis of the multi-layer film development process of design optimization algorithm. We used Matlab to compile clustering global optimization algorithm based on film design optimization procedure, and successfully designed broadband multi-layer AR coating from visible to near-infrared.Then, based on the comprehensive study on the theory of optimization algorithms and detailed analysis of the current mainstream multi-layered film deposition processes, broadband multi-layer AR film is successfully prepared by using ion-assisted thermal evaporation technique.In addition, theoretical and experimental research on the gradient refractive index nano-structure was carried out, the theoretical model of graded index antireflection structure was analyzed. AR coating with nano-structured surface was successfully prepared using metal nano-particles and wet etching method. Besides, we studied the nano-structured AR coating prepared by using monolayer colloidal crystal template and reactive ion etching technique.Finally, we put forward a new kind of nano-structured AR coating, which combine a proposed nanostructure and multi-layers coating to achieve wide-angle wide-band antireflection properties. By using polystyrene microspheres template and reactive ion beam etching method, regularly arranged conical surface nanostructure was successfully prepared, and finally the prepared composite nano-structured coating has a near-perfect wide-angle broadband antireflective property.