Related papers: Giant Coulomb broadening and Raman lasing on ionic…

Cooling antihydrogen atoms is important for future experiments both to test the fundamental CPT symmetry by high-resolution laser spectroscopy and also to measure the gravitational acceleration of antimatter. Laser-cooling of antihydrogen…

Raman transitions have a wide range of applications in atomic physics and have recently been proposed as a means for improving high-precision high-voltage measurements. Here, we present a theoretical analysis and a first experimental…

We study population distributions and lasing actions of N_2^+ driven by femtosecond lasers with various wavelengths, and uncover an efficient ionic excitation mechanism induced by synchronized ionization and multiphoton resonance. Our…

We observe a density-dependent collective suppression of optical pumping between the hyperfine ground states in an array of submicrometer-sized clouds of cold rubidium atoms. The suppressed Raman transition rate can be explained by strong…

In the Coulomb explosion acceleration regime, an ion bunch with a narrow energy range exhibits a thin shell shape with a certain diameter. The ion cloud has a layered structure of these ion bunches with different energies. The divergences…

Renormalization of the Coulomb interaction in layered metals results in a strongly anisotropic plasma mode with low frequencies for small components of wave vector in the in-plane direction. Interaction of electrons with this mode was found…

We observe the buildup of a frequency-shifted reverse light field in a unidirectionally pumped high-$Q$ optical ring cavity serving as a dipole trap for cold atoms. This effect is enhanced and a steady state is reached, if via an optical…

Using three-dimensional kinetic simulations, we examine the emission of collimated gamma-ray beams from structured laser-irradiated targets with a pre-filled cylindrical channel. The channel guides the incident laser pulse, enabling…

Wakefield excitation by structured electron bunches in hollow gaps between plasma wedges is studied using three-dimensional particle-in-cell simulations. The main part of the electron bunch has a triangular current distribution in the…

We show lasing without population inversion in a closed four-level atomic system which is no longer incoherently pumped on the transition at which lasing occurs. The four-level system can overcome some limits in the typical lambda-type and…

We consider the excitation dynamics of the two-photon \sts transition in a beam of atomic hydrogen by 243 nm laser radiation. Specifically, we study the impact of ionization damping on the transition line shape, caused by the possibility of…

This paper shows that in Laser-Induced Plasma Lasers (LIPL), the collisionally assisted transitions that lead to the inversion population on an upper-generation level E_up may be partly forbidden. The spin-orbit coupling may…

We propose a two-dimensional interferometry based on electron wave packet interference with a cycle-shaped orthogonally polarized two-color laser field. With such method, sub-cycle and inter-cycle interferences can be disentangled into…

Propagation of short and ultra-intense laser pulses in a semi-infinite space of overdense hydrogen plasma is analyzed via fully-relativistic, real geometry particle-in-cell (PIC) simulations including radiation friction. The relativistic…

We measure the expansion of an ultracold plasma across the field lines of a uniform magnetic field. We image the ion distribution by extracting the ions with a high voltage pulse onto a position-sensitive detector. Early in the lifetime of…

The realization of ultrahigh quality (Q) resonators regardless of the underpinning material platforms has been a ceaseless pursuit, because the high Q resonators provide an extreme environment of storage of light to enable observations of…

Electromagnetically induced transparency and coherent population trapping were observed in a hot (1000 K) calcium vapor embedded into an electrical gas discharge. Unexpectedly large transparencies (of up to 70%) were observed under very…

Large clouds of cold atoms prepared in a magneto-optical trap can develop spatio-temporal instabilities when the frequency of the trapping lasers is brought close to the atomic resonance. This system bears close similarities with trapped…

We have proposed and demonstrated a fast and robust method of population transfer between two quantum states using a quadratically chirped laser source. Incorporating the Jaynes-Cummings in a full quantum description of the interaction, and…

In regimes far beyond the wavebreaking threshold of Raman amplification, we show that significant amplifcation can occur after the onset of wavebreaking, before phase mixing destroys the coherent coupling between pump, probe and plasma…