Summary: IEEE TRANSACTIONS ON NANOTECHNOLOGY, VOL. 7, NO. 1, JANUARY 2008 91
Graphene Terahertz Plasmon Oscillators
Farhan Rana
Abstract--In this paper we propose and discuss coherent
terahertz sources based on charge density wave (plasmon) amplifi-
cation in two-dimensional graphene. The coupling of the plasmons
to interband electron­hole transitions in population inverted
graphene layers can lead to plasmon amplification through stimu-
lated emission. Plasmon gain values in graphene can be very large
due to the small group velocity of the plasmons and the strong
confinement of the plasmon field in the vicinity of the graphene
layer. We present a transmission line model for plasmon propaga-
tion in graphene that includes plasmon dissipation and plasmon
interband gain due to stimulated emission. Using this model, we
discuss design for terahertz plasmon oscillators and derive the
threshold condition for oscillation taking into account internal
losses and also losses due to external coupling. The threshold con-
dition is shown to depend on the ratio of the external impedance
and the characteristic impedance of the plasmon transmission
line. The large gain values available at terahertz frequencies in

Source: Afshari, Ehsan - School of Electrical and Computer Engineering, Cornell University

Collections: Engineering