Looking Back 30, 20, and 10 Years Ago in OPN Rebecca Robinson Thin-film security devices; LEDs for headlights; silicon marbles. Log in or become a member to view the full text of this article. This article may be available for purchase via the search at Optica Publishing Group. Optica Members get the full text of Optics & Photonics News, plus a variety of other member benefits. Publish Date: 01 July 2019 Add a Comment Please enable JavaScript to view the comments powered by Disqus.