US researchers say they have developed a technique that can significantly improve the efficiency of the traditional incandescent light bulb, by recycling the waste energy and focusing it back on the filament where it is re-emitted as visible light. http://www.bbc.com/news/science-environment-35284112 Paper: http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2015.309.html
