Computer screen lighting research. Researcher comparing computer screens lit by a flat Planon lamp (left) and a traditional liquid crystal display (LCD). A Planon lamp is a 1cm-thick fluorescent lamp with a lifespan more than double that of traditional fluorescent lamps. It also operates without the polluting mercury vapour they contain. The lamp emits light evenly over its surface, and is twice as bright as an LCD monitor. It works by stimulating xenon gas, causing it to generate ultraviolet radiation which is re-emitted as visible light by the phosphor. The Planon lamp was developed by Siemens. Photographed in Germany.