ABSTRACT
In this chapter, the authors experimentally observe fast relaxation and relatively slow recombination dynamics of photogenerated electrons/holes in a heteroepitaxial graphene-on-silicon material under pumping with a 1550 nm, 80 fs pulsed fiber laser and probing with the corresponding terahertz (THz) beam generated by and synchronized with the pumping laser. The time-resolved electric-nearfield intensity originating from the coherent THz photon emission is electrooptically sampled in total-reflection geometry. The authors observe amplified stimulated THz emission in optically pumped and THz-probed epitaxial graphene heterostructures. The incident photon spectra are expected to be reflected in the THz photoemission spectra as evidence that such a process occurs. The time-resolved field emission properties are measured by an electrooptic sampling method in total-reflection geometry. The authors also observes coherent amplified stimulated THz emissions arising from the fast relaxation and relatively slow recombination dynamics of photogenerated electrons/holes in an epitaxial graphene heterostructures.
