Terahertz applications of graphene

Owing to the unique gapless, linear band structure, ultrahigh carrier mobilities altogether with other extraordinary properties, graphene has attracted much attention since its first successful isolation and is expected to ease the dearth of techniques in this "last frontier in the electromagnetic spectrum to be exploited" or so-called "Terahertz technology gap. " In this chapter, we discuss recent progress in graphene-based research for Terahertz applications. We start from discussing fundamental basis of the synthesizing, optoelectronic, mechanical and chemical properties of graphene. Then we review a number of recent advances from Terahertz generation, detection and manipulation perspective. Optically or electrically pumped graphene is predicted to exhibit population inversion near the Dirac point, which leads to a negative dynamic conductivity in a wide THz spectral range. An optically pumped THz laser has been substantiated with a Fabri-Perot resonant cavity design. Both an electrically and chemically tunable Fermi level of graphene has been used to modulate THz waveforms and means to enhance light absorption in monolayer graphene for more modulation depth are also discussed. In this chapter, Potential Terahertz applications to use graphene in future communication, electronics and other fields, are illustrated in detail in this chapter.