Feature The Solar Zone Richard C. Powell Deep in the Arizona desert, a testing facility is advancing photovoltaic technologies. 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 October 2018 Add a Comment Please enable JavaScript to view the comments powered by Disqus.