ABSTRACT
In this chapter, the authors fabricate prototype terahertz (THz) amplifiers composed of chemical-vapor-deposition (CVD)-grown graphene and a metal mesh structure and observe extremely amplified THz emission by using an electro-optic sampling method. A structure having a periodic array of holes in a metal sheet, referred to as metal mesh structure, has been known to exhibit extraordinary optical transmission (EOT) at wavelengths slightly longer than the period of the array. The CVD-grown monolayer graphene was transferred onto the surface of the GaAs substrate with a thickness of 600 µm. The EOT with metal mesh structure has been reported in a wide range of the electromagnetic (EM) wave regions including that of THz. The authors use a commercially available finite-difference time domain EM simulator to investigate the transmission and reflection characteristics of the metal mesh structure without a gain medium. They speculate that the reason for the results might be the coupling between photogenerated electrons and resonant field oscillation due to induced Surface plasmon polaritons.
