Optical filter could vastly improve efficiency of incandescent lightbulbs
DOI: 10.1063/PT.5.029503
BBC : The incandescent lightbulb, which was commercially developed by Thomas Edison in the 1880s, was widely used for more than a century. However, because the bulbs waste a lot of energy as heat, they have recently been phased out in many countries. Researchers at MIT have now developed a higher-efficiency incandescent bulb by surrounding the filament with thin layers of a light-controlling crystal. The material allows visible light to pass through but reflects IR light back to the filament, where it is reabsorbed and reemitted as visible light. Although the researchers’ proof of concept reaches an efficiency of only 6.6%, in theory the efficiency of such bulbs could be boosted as much as 40%.
