▎ 摘　　要

In this paper, a possible way to achieve lasing from the THz to the extreme UV domain due to stimulated scattering of graphene plasmons (GPs) on free electrons is considered. The analytical-quantitative description of the proposed free electron laser scheme is based on a self-consistent set of Maxwell-Vlasov equations. We study the downconversion as well as the upconversion. It is shown that the coherent downconversion of infrared radiation to THz can be achieved using a source of very non-relativistic electrons at the resonant coupling with the GPs. Due to the strongly confined GPs, the upconversion of mid-infrared to extreme UV radiation can be achieved with mildly relativistic electron beams. The latter is a promising mechanism for a tabletop short-wavelength free-electron nanolaser.