▎ 摘　　要

Injection pumping of the pristine graphene is a promising alternative to optical pumping, but it is not obvious how to properly combine electronic and plasmonic features in one and the same device in order to obtain the terahertz plasmon amplification in graphene with injection pumping. This paper shows that an amplified plasmon mode can be effectively excited at the plasmon resonance frequencies in an active ungated region graphene with injecting (absorbing) gated parts of the periodic graphene structure. Necessary conditions for the plasmon lasing in the structure are found. Published by AIP Publishing.