Observation of spontaneous terahertz emission from optically pumped monolayer intrinsic graphene

摘要

Due to the unbalance between the nonequilibrium ultrafast carrier energy relaxation and relatively slow recombination dynamics in optically pumped graphene, the population inversion and resultant gain can be obtainable in a wide terahertz (THz) frequency region. We report on experimental observation of a spontaneous THz emission in optically pumped graphene. Observed emission spectra agree well with theoretical calculations.