Graphene — sheets of carbon just one atom thick with exceptional mechanical and electrical properties — also has the potential to be used as a laser.

Tianqi Li of the Ames Laboratory at Iowa State University and his colleagues demonstrate that 'pumping' a graphene monolayer with 35-femtosecond pulses of light causes the graphene to reach an excited state called a population-inverted state. It can then be triggered to emit light. With strong pumping, the graphene emits more light across a range of near-infrared frequencies than it absorbs — a sign of the 'optical gain' that is crucial for lasers.

Graphene's unique properties could improve the performance of current laser technology.

Phys. Rev. Lett. 108, 167401 (2012)