相关论文: Terahertz and higher-order Brunel harmonics: from …
Brunel harmonics appear in the optical response of an atom in process of laser-induced ionization, when the electron leaves the atom and is accelerated in the strong optical field. In contrast to recollision-based harmonics, the Brunel…
Electromagnetic emissions, known as Brunel radiations, are produced in plasmas through the coupling between the free electron density and ultrafast ionizing laser pulses. The radiation spectrum generated in laser-gas interactions is here…
Radiation during strong-field tunneling ionization is investigated. The spontaneous as well as the coherent components of the radiation are calculated describing the ionization dynamics via the strong field approximation and the role of the…
Organic semiconductors have attracted extensive attention due to their excellent optical and electronic properties. Here, we present an experimental and theoretical study of Brunel harmonic generation in two types of porphyrin thin films:…
The phenomenon of Euclidean resonance (a strong enhancement of quantum tunneling through a nonstationary potential barrier) is applied to disintegration of atoms and molecules through tunnel barriers formed by applied constant and…
The coherent radiation spectrum of two-level polar molecules with UV transition is studied at the multiphoton resonant excitation by a moderately strong laser field. The spectrum corresponding to harmonic generation and low-frequency…
The higher order harmonic generation process in the nonperturbative regime at the interaction of coherent electromagnetic radiation with the AB-stacked bilayer graphene at high Fermi energies is considered. The applied coherent…
The multiphoton ionization of hydrogen by a strong bichromatic microwave field is a complex process prototypical for atomic control research. Periodic orbit analysis captures this complexity: Through the stability of periodic orbits we can…
We present a theoretical analysis of high-order harmonic generation from ion-atom collisions in the presence of linearly polarized intense laser pulses. Photons with frequencies significantly higher than in standard atomic high-harmonic…
The generation of the below threshold harmonics (BTHs) under different driving laser intensities is investigated. The linearly shifting of photon energy and resonantly enhancement of photon yield of the harmonics from 23rd (H23) to 27th…
A highly intense femtosecond laser pulse incident on a plasma target of supercritical density, gives rise to reflected high-order harmonics of the laser frequency. The radiation model adopted here considers Brunel electrons -those…
Ultrafast charge transport in strongly biased semiconductors is at the heart of highspeed electronics, electro-optics, and fundamental solid-state physics. Intense light pulses in the terahertz (THz) spectral range have opened fascinating…
Photocurrent-induced harmonics appear in gases and solids due to tunnel ionization of electrons in strong fields and subsequent acceleration. In contrast to three-step harmonic emission, no return to the parent ions is necessary. Here we…
Terahertz (THz) emission by two-color, ultrashort optical pulses interacting with underdense helium gases at ultrahigh intensities ($> 10^{19}\,\mathrm{W/cm}^2$) is investigated by means of 3D particle-in-cell simulations. The THz field is…
We report on a new contribution to the microwave response of a two-dimensional electron system in magnetic field which originates from excitation of virtual Bernstein modes. These collective modes emerge as a result of interaction between…
The frequency dependence of the peak-valley pairs occurring in the magnetoresistivity of a two-dimensional electron system under enhanced microwave irradiation, which are considered to associate with multiphoton processes, is examined in…
The emission of above-ionization-threshold harmonics results from the recombination of two electron wavepackets moving along a "short" and a "long" trajectory in the atomic continuum. Attosecond pulse train generation has so far been…
Multi-photon processes are the essence of nonlinear optics. Optical harmonics generation and multi-photon absorption, ionization, polymerization or spectroscopy are widely used in practical applications. Generally, the rate of an n-photon…
We consider double ionization of negative bromine ion in intense low-frequency electromagnetic fields. By solving numerically the two-electron time-dependent Schr{\" o}dinger equation we demonstrate that while for pulses of a few tens of…
We derive a simple theory for high-order harmonic generation due to pumping a noninteracting metal with a large amplitude oscillating electric field. The model assumes that the radiated light field arises from the acceleration of electrons…