Related papers: Superradiant Undulator Radiation for Selective THz…
Natively, atomic and molecular processes develop in a sub-femtosecond time scale. In order to, for instance, track and capture the electron motion in that scale we need suitable `probes'. Attosecond pulses configure the most appropriate…
Streaking of photoelectrons with optical lasers has been widely used for temporal characterization of attosecond extreme ultraviolet pulses. Recently, this technique has been adapted to characterize femtosecond x-ray pulses in free-electron…
This is a brief overview of the main physical ideas for application of field effect transistors for generation and detection of TeraHertz radiation. Resonant frequencies of the two-dimensional plasma oscillations in FETs increase with the…
The recently implemented APPLE-III device at FLASH2 is an undulator source providing tunable, femtosecond spontaneous X-rays in the range of 2 - 3.5 keV at the 3rd and 5th harmonics. This work demonstrates its applicability for EUV FEL…
Although the THz spectral range experiences a tremendous grow of interest for at least two decades, it is still one of the least explored but most exciting areas to study light-matter interaction. Due to the small photon energy of THz…
High-field terahertz (THz) pulse generation is investigated through the interaction of an intense single-color CO2 laser pulse with helium (He) gas targets. Employing multi-dimensional Particle-In-Cell (PIC) simulations, this study reveals…
In spin-based electronics, information is encoded by the spin state of electron bunches. Processing this information requires the controlled transport of spin angular momentum through a solid, preferably at frequencies reaching the so far…
Terahertz quantum cascade lasers (THz QCLs) are chip-scale semiconductor lasers operating in the frequency range between 1-6 THz, useful as compact sources for spectroscopy, communications, and non-destructive imaging and testing. Here, we…
Harmonic lasing provides an opportunity to extend the photon energy range of existing and planned X-ray FEL user facilities. Contrary to nonlinear harmonic generation, harmonic lasing can generate a much more intense, stable, and…
Free-electron lasers (FELs) have been built ranging in wavelength from long-wavelength oscillators using partial wave guiding through ultraviolet through hard x-ray that are either seeded or start from noise (SASE). In addition, FELs that…
We describe a method for producing high power, coherent x-ray pulses from a free electron laser with femtosecond scale periodic temporal modulation of the polarization vector. This approach relies on the generation of a temporal intensity…
The generation of harmonic radiation through a non-linear mechanism driven by bunching at fundamental frequency is an important option in the operation of high gain Free-Electron Lasers (FELs). The use of harmonic generation at a large…
The terahertz (THz) spectral range is central to high-speed communication, precision metrology, sensing technologies, and a range of fundamental scientific investigations. Achieving these capabilities in practical systems increasingly…
We demonstrate that pulsed THz radiation produced in air by a focused ultrashort laser pulse can be steered to large angles or even in the backward direction with respect to the laser propagation axis. The emission angle is adjusted by the…
High-order harmonic generation in the presence of a chirped THz pulse is investigated numerically with a complete 3D non-adiabatic model. The assisting THz pulse illuminates the HHG gas cell laterally inducing quasi-phase-matching. We…
We demonstrate optical coherent control of the emission direction of THz radiation. Femtosecond laser pulses are used to excite different types of ultrafast photocurrents along different directions in a bulk GaAs sample. The overall…
In order to effectively improve the output quality of X-ray free electron laser (XFEL), we theoretically propose an XFEL scheme seeded by atomic inner-shell laser. As well known, an atomic inner-shell laser based on neutral atoms and pumped…
The Maxwell equations based 3D analytical solution for the terahertz half-cycle electromagnetic wave transition radiation pulse has been found. This solution describes generation and propagation of transition radiation into free space from…
The excitation of radial and longitudinal wake-fields by two co-propagating chirped laser pulses in a rippled, magnetized plasma has been examined. This study aimed to clarify the spatiotemporal evolution of wake structures and assess their…
We propose a novel scheme for frequency-tunable sub-cycle electromagnetic pulse generation. To this end a pump electron beam is injected into an electromagnetic seed pulse as the latter is reflected by a mirror. The electron beam is shown…