Related papers: Coherent {\gamma}-ray Generation By Partially Stri…
Generically, a laser is composed of an optical resonator coupled to a gain medium. If the light amplification via stimulated emission dominates the mirror losses, the emitted light is coherent. Recent studies have shown that sub-wavelength…
High harmonic generation traditionally combines ~100 near-infrared laser photons, to generate bright, phase matched, extreme ultraviolet beams when the emission from many atoms adds constructively. Here we show that by guiding a…
The spectroscopic techniques for time-resolved fine analysis of matter require coherent X-ray radiation with femtosecond duration and high average brightness. Seeded free-electron lasers (FELs), which use the frequency up-conversion of an…
The possibility of $\gamma-$ray laser generation by the radiation of wiggling electrons in an usual background laser is discussed.
We study coherent backscattering of a quasi-monochromatic laser by a dilute gas of cold two-level atoms. We consider the perturbative regime of weak intensities, where nonlinear effects arise from {\em inelastic} two-photon scattering…
We suggest that coherent radiation may occur in relativistic collisionless shocks via two-stream Weibel instabilities. The coherence amplifies the radiation power by many orders [$\sim 10^{12}$ in Gamma-Ray Bursts (GRBs)] and particles cool…
It is known that the alignment of an high-energy e- beam with specific crystal directions leads to a significant increase of the coherent radiation emission. This enhancement can be exploited to create an intense photon source. An elective…
We demonstrate that photonic crystals can be used to generate powerful and highly coherent laser radiation when injecting a beam of free electrons. Using theoretical investigations we present the startup dynamics and coherence properties of…
We consider the resonant scattering of coherent electromagnetic waves by a Raman-like process in the gamma ray range off electrostatic modes in a quantum plasma using a collective Klein-Gordon-Maxwell model. The growth rates for the most…
Based on collisions between the 100 PW laser and 8 GeV superconducting linear accelerator constructing at the Shanghai hard X-ray free electron laser system (SHINE), the building of GeV-level $\gamma$-ray as well as positron beams are…
High-order harmonic generation from atomic systems is considered in the crossed fields of a relativistically strong infrared laser and a weak attosecond-pulse train of soft x-rays. Due to one-photon ionization by the x-ray pulse, the…
A high-power laser pulse at normal incidence onto a plane solid target will generate odd harmonics of its frequency. However, the spacing of the harmonic lines in this configuration is fixed. Here, we study harmonic generation using two…
We present the first experimental evidence of stimulated Raman re-scattering of a laser in plasma: The scattered light produced by the Raman instability is intense enough to scatter again through the same instability. Although never…
Many studies have shown that high-energy $\gamma$-photon beams can be efficiently generated via nonlinear Compton scattering driven by laser pulses with intensities $> 10^{22}\rm{W/cm^2}$ recently available in laboratories. Here, we propose…
X-ray devices are far superior to optical ones for providing nanometre spatial and attosecond temporal resolutions. Such resolution is indispensable in biology, medicine, physics, material sciences, and their applications. A bright…
Gamma-ray flash generation in near critical density (NCD) target irradiated by four symmetrical colliding laser pulses is numerically investigated. With peak intensities about $10^{23}$ W/cm$^2$, the laser pulses boost electron energy…
The x-ray vortex optical beam, distinguished by its topological charge and orbital angular momentum, offers new insights in probing complex electronic structures, enhancing material characterization, and advancing high-resolution imaging…
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…
Advanced accelerator-based light sources such as free electron lasers (FEL) accelerate highly relativistic electron beams to generate incredibly short (10s of femtoseconds) coherent flashes of light for dynamic imaging, whose brightness…
When a resonant laser sent on an optically thick cold atomic cloud is abruptly switched off, a coherent flash of light is emitted in the forward direction. This transient phenomenon is observed due to the highly resonant character of the…