The Incandescent Bulb, Revisited

Synopsis

In a 2016 paper published in Nature Nanotechnology, researchers at the Massachusetts Institute of Technology and Purdue University have brought a new perspective to an old technology. The incandescent light bulb, based on the tungsten filament, has always suffered from a fundamental inefficiency: most of the energy used by the filament is lost as invisible infrared radiation. In their work, Ilic et al. use current principles of nanophotonics to design layered stacks of dielectric materials that tailor the radiation emitted by the filament and increase the efficiency by a substantial amount. Their proof-of-principle experiment demonstrates the potential of this new technology to create incandescent emitters with efficiencies competitive with modern light sources, excellent colour reproduction, and scalable power. In addition, the ability to control the emission spectrum of high-temperature sources could lead to significant improvements in the performance of photovoltaic technologies.