Another example of creative recycling (Score 1)

do a search on gradient antireflective films. This was done in the 1980s and used extensively for very high energy laser optics by several labs. By either reacting glass surfaces, or by coating the surfaces with nanoparticles, one can readily produce surfaces with essentially no reflectance (0.01%) over the entire visible spectrum. What is produced is a porosity gradient whose index varies from 1.0 at the surface to that of the bulk material. Since there is no clear interface, reflectance is broadband. At one government lab, meter-sized optics were treated. I remember that one visiting congressman ran into one of the windows because it was, functionally, invisible. These technologies never saw broad acceptance because porous surfaces react with the environment, and reflectance increases (requires periodic cleaning). Sigh, it seems that scholarship is dead...