At the end of the Eighties I was commissioned to revitalize the false ceiling of the Visitor Center at the CERN. I conceived a tensile structure in steel and fiber optics, later substituted by halogen dichroic spotlights equipped with lenses: the technology at the time only permitted an installation with fiber optics in glass but the length available was not sufficient for the project I had in mind.
Spotlights with a contoured focal opening came to my rescue! Two years later technology was already much more advanced and I was able to achieve my Obelisco solare (Solar obelisk) with fiber optics in methacrylate.