相关论文: Sub-cycle Nanotip Field Emission of Electrons Driv…
We report on sub-cycle terahertz light-field emission of electrons from tungsten nanotips under extreme conditions corresponding to a Keldysh parameter $\gamma_K\approx10^{-4}$. Local peak THz fields up to 40~GV/m are achieved at the apex…
We present a novel scheme to obtain robust, narrowband, and tunable THz emission by using a nano-dimensional overdense plasma target that is irradiated by two counter-propagating detuned laser pulses. So far, no narrowband THz sources with…
Terahertz pulse generation by ultra-intense two-color laser fields ionizing gases with near- to far-infrared carrier wavelength is studied from particle-in-cell (PIC) simulations. For long wavelength ($10.6\ \mu$m) promoting a large ratio…
We present a theoretical investigation of terahertz (THz) generation in laser-induced gas plasmas. The work is strongly motivated by recent experimental results on micro-plasmas, but our general findings are not limited to such a…
While field-driven electron emission is theoretically understood down to the subcycle regime, its direct experimental temporal characterization using long-wavelength terahertz (THz) fields remains elusive. Here, by driving a graphite tip…
The active control of matter by strong electromagnetic fields is of growing importance, with applications all across the optical spectrum from the extreme-ultraviolet to the far-infrared. In recent years, phase-stable terahertz (THz) fields…
Field-emission patterns from a clean tungsten tip apex induced by femtosecond laser pulses have been investigated. Strongly asymmetric field-emission intensity distributions are observed depending on three parameters: (1) the polarization…
The advent of ultrafast science with pulsed electron beams raised the need in controlling the temporal features of the electron pulses. One promising suggestion is the nano-selective quantum optics with multi-electrons, which scales…
Electromagnetic radiation within the terahertz (THz) frequency range is of great interest for applications in remote sensing and time-domain spectroscopy. The laser-induced plasmas are promising mediums for generating THz radiation. It has…
The tremendous applications of terahertz (THz) spectroscopy and imaging require THz sources in different parameters. We propose a novel scheme to generate single-cycle powerful THz pulses by ultrashort intense laser pulses incident…
We propose a method to generate high field terahertz (THz) radiation with peak strength of GV/cm level in the THz frequency gap range 1-10 THz using a relativistic laser interaction with a gaseous plasma target. Due to the effect of local…
We theoretically investigate the interaction of near-infrared few cycle laser pulses of moderate intensity with nano-scale metal tips. Macroscopic field enhancement leads to coherent electron emission from the tip apex. Electron spectra are…
In this article we present coherent control of above-threshold photoemission from a tungsten nanotip achieving nearly perfect modulation. Depending on the pulse delay between fundamental (1560 nm) and second harmonic (780 nm) pulses of a…
Broadband ultrashort terahertz (THz) pulses can be produced using plasma generation in a noble gas ionized by femtosecond two-color pulses. Here we demonstrate that, by using multiple-frequency laser pulses, one can obtain a waveform which…
Photoelectron field emission, induced by femtosecond laser pulses focused on metallic nanotips, provides spatially coherent and temporally short electron pulses. The properties of the photoelectron yield give insight into both the material…
Studies employing nonlinear interactions of THz pulses are nowadays a promising scientific research field. To capture these phenomena, THz pulses with energy ranging from hundreds of \muJ to the mJ level are necessary. However, techniques…
Free-space super-strong terahertz (THz) electromagnetic fields offer multifaceted capabilities for reaching extreme nonlinear THz optics, accelerating and manipulating charged particles, and realizing other fascinating applications.…
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…
We present an experiment studying the interaction of a strongly focused 25 fs laser pulse with a tungsten nanotip, investigating the different regimes of laser-induced electron emission. We study the dependence of the electron yield with…
Using high-resolution, two-dimensional particle-in-cell simulations, we investigate numerically the mechanisms of terahertz (THz) emissions in submicron-thick carbon solid foils driven by ultraintense ($\sim 10^{20}\,\rm W\,cm^{-2}$),…