Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

After a brief introduction into time-resolved spectroscopy we focus on polarization-resolved pump-probe experiments at different infrared photon energies. Here an anisotropy induced by the polarization of the pump beam is observed. For photon energies below the optical photon energy (~200 meV) the relaxation dynamics is dominated by Coulomb scattering. The experiments show directly that non-collinear scattering, which leads to an isotropic distribution, is remarkably slow at low fluences, namely on a timescale of 5 ps. The findings are in good agreement with microscopic theory. The timescale of this thermalization is very attractive for applications where hot carriers in graphene are exploited in detectors or modulators of infrared radiation.