Enhanced Terahertz Emission from Monolayer Graphene with Metal Mesh Structure

The development of compact, low-cost sources and detectors operating at room temperature is needed to fully use terahertz (THz) electromagnetic waves in a variety of applications. Photo-excited graphene is expected to exhibit population inversion and enable the fabrication of a novel THz laser. We previously proposed a THz amplifier as a basic element in a THz laser by combining the population inversion in photo-excited graphene with the electric field enhancement due to the spoof surface plasmon polaritons induced on the surface of a metal mesh structure. For this work, we fabricated prototype THz amplifiers composed of chemical-vapor-deposition-grown graphene and a metal mesh structure and observed extremely amplified THz emission by using an electro-optic sampling method.