I.M. Moiseenko – Ph.D. (Phys.-Math.), Junior Research Scientist, 

Saratov Branch of Kotelnikov Institute of Radio Engineering and Electronics

E-mail: MoiseenkoIM@yandex.ru

V.V. Popov – Dr.Sc. (Phys.-Math.), Head of Laboratory, 

Saratov Branch Kotelnikov Institute of Radio Engineering and Electronics

D.V. Fateev – Ph.D. (Phys.-Math.), Senior Research Scientist,

Saratov Branch Kotelnikov Institute of Radio Engineering and Electronics; Saratov State University

Problem formulating. Currently, there are no compact, efficient terahertz radiation sources operating at room temperature. To create such sources and amplifiers, periodic lattice structures based on graphene with an inverse population of charge carriers can be used.

Goal. Introduce the concept of a plasmon terahertz radiation amplifier operating at room temperature. To evaluate the possibility of amplification during unidirectional propagation of terahertz plasmons in a spatially asymmetric structure with a double lattice gate.

Result. A periodic structure with an asymmetric unit cell based on graphene with inversion of charge carriers allows the incident THz wave to be converted into an amplifying unidirectional THz plasmon. The energy flux of plasmons along the structure in one direction can exceed the antidirectional energy flux of plasmons by more than an order of magnitude. To achieve unidirectional amplification of plasmons in graphene, simultaneous excitation of the radiation and non-radiation plasmon modes at the same frequency is necessary. This is possible only with spatial asymmetry of the gate array electrodes. Practical meaning. The results of this work can be used to create terahertz converters of electromagnetic radiation into a directional undamped or amplifying plasma wave. The considered devices can be used as effective sources of traveling THz plasmons in integrated THz plasmon schemes.

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