Sharif University of Technology Scientia Iranica 1026-3098 27 6 2020 12 01 Spaser Based on Graphene Tube 3084 3095 21257 10.24200/sci.2019.50322.1635 EN S. Behjati Ardakani Department of Electrical Engineering, Sharif University of Technology, Azadi Avenue, Tehran, Iran R. Faez Department of Electrical Engineering, Sharif University of Technology, Azadi Avenue, Tehran, Iran Journal Article 2018 01 23 In this paper, we propose a structure for graphene spaser and develop an electrostatic model for quantizing plasmonic modes. Using this model, one can analyze any spaser consisting of graphene in the electrostatic regime. The proposed structure is investigated analytically and the spasing condition is derived. We show that spasing can occur in some frequencies where the Quality factor of plasmonic modes is higher than some special minimum value. Finally, an algorithmic design procedure is proposed, by which one can design the structure for a given frequency. As an example, a spaser with plasmon energy of 0.1 eV is designed. https://scientiairanica.sharif.edu/article_21257_8d4a2a1cfd4b024e60e0f33370a62ceb.pdf