ABSTRACT
Terahertz (THz) devices have been investigated over the last decade to utilize THz waves for non-destructive sensing and high-speed wireless communications. In this chapter, the authors analyze a THz amplifier utilizing this negative dynamic conductivity combined with electric field enhancements due to surface plasmon polaritons induced on a metal mesh and with a resonant structure. They propose a THz amplifier with a resonant structure to increase gain, and reports the characteristics through finite-difference time-domain (FDTD) electromagnetic simulations. The introduction of the mirror causes multiple reflections between the metal mesh and mirror. When the amplification of the reflected waves in the multiple layers of graphene (MLG) is ignored, the amplitude of the wave reflected from the amplifier with the mirror should equal the emittance of the mirror-less amplifier. The authors also propose MLG-based THz amplifiers with a resonant structure, and investigated our amplifiers through FDTD simulations. These amplifiers predicted remarkably enhanced emittance compared with amplifiers without a resonant structure.
