Related papers: Ultrafast Photoluminescence from Graphene
We report on the development of an ultrafast Transmission Electron Microscope based on a cold field emission source which can operate in either DC or ultrafast mode. Electron emission from a tungsten nanotip is triggered by femtosecond…
Irradiation of sharp silver tips with femtosecond laser pulses leads to photoassisted coherent field emission without a static field. We reconstruct the time profile of the emission, and show that the process is entirely governed by the…
Graphene-based photodetectors, taking advantage of high carrier mobility and broadband absorption in graphene, have recently experienced rapid development. However, their performances with respect to the responsivity and bandwidth are still…
Sub-wavelength graphene structures support localized plasmonic resonances in the terahertz and mid-infrared spectral regimes. The strong field confinement at the resonant frequency is predicted to significantly enhance the light-graphene…
We establish an analogy between spectra of Dirac fermions in laser fields and an electron spectrum of graphene superlattices formed by static 1D periodic potentials. The general relations between a laser-controlled spectrum where electron…
Graphene, a monolayer of carbon atoms arranged in a hexagonal pattern, provides a unique two-dimensional (2D) system exhibiting exotic phenomena such as quantum Hall effects, massless Dirac quasiparticle excitations and universal absorption…
We study the carrier dynamics in epitaxially grown graphene in the range of photon energies from 10 - 250 meV. The experiments complemented by microscopic modeling reveal that the carrier relaxation is significantly slowed down as the…
Ultrafast control of electron dynamics in solid state systems has recently found particular attention. By increasing the electric field strength of laser pulses, the light-matter interaction in solids might turn from a perturbative into a…
Ultrafast electron-phonon relaxation dynamics in graphene hides many distinct phenomena, such as hot phonon generation, dynamical Kohn anomalies, and phonon decoupling, yet still remains largely unexplored. Here, we unravel intricate…
The ultrafast relaxation and recombination dynamics of photogenerated electrons and holes in epitaxial graphene are studied using optical-pump Terahertz-probe spectroscopy. The conductivity in graphene at Terahertz frequencies depends on…
Spontaneous optical emission of graphene irradiated by intense single-cycle terahertz pulses was investigated experimentally and explained theoretically. We found that emitted photons are polarized predominantly perpendicular to the…
A detailed analysis of the photon emission spectra of an electron scattered by a laser pulse containing only very few cycles of the carrying electromagnetic field is presented. The analysis is performed in the framework of strong-field…
In this study,we combined time-resolved terahertz spectroscopy along with transient absorption spectroscopy to revisit the interlayer non-equilibrium carrier dynamics in largely lateral size Gr/MoS2 heterostructure fabricated with chemical…
Controlling the energy flow processes and the associated energy relaxation rates of a light emitter is of high fundamental interest, and has many applications in the fields of quantum optics, photovoltaics, photodetection, biosensing and…
Low-energy reflectivity of electrons from single- and multi-layer graphene is examined both theoretically and experimentally. A series of minima in the reflectivity over the energy range of 0 - 8 eV are found, with the number of minima…
We investigated Raman spectra of single-layer and multi-layer graphene under ultraviolet laser excitation at the wavelength of 325 nm. It was found that while the G peak of graphene remains pronounced in UV Raman spectra, the 2D band…
We demonstrate laser-plasma acceleration of high charge electron beams to the ~10 MeV scale using ultrashort laser pulses with as little energy as 10 mJ. This result is made possible by an extremely dense and thin hydrogen gas jet. Total…
The theory of optical effects in hydrogenated graphene (graphane) in terahertz and infrared range is developed, including the analysis of complex conductivity, reflection coefficient for graphane on a substrate and dispersion of surface…
We perform a femtosecond-THz optical pump-probe spectroscopy to investigate the cooling dynamics of hot carriers in quasi-free standing bilayer epitaxial graphene. We observed longer decay time constants, in the range of 2.6 to 6.4 ps,…
The enhanced nonlinear optical response of a one-dimensional (1D) photonic crystal (PC) made from polymers and graphene composites is observed. The graphene PC was fabricated by spin-coating. It shows obvious bandgaps at two wavelengths in…