相关论文: Similar angular THz radiation pattern emitted by f…
Numerical simulations of laser-plasma interactions demonstrate the generation of axially polarized electromagnetic pulses (EMPs) that radiate away energy with a characteristic frequency determined by the plasma frequency, in the THz range…
During femtosecond laser filamentation in air, the velocity ratio (K) between the terahertz (THz) phase velocity and the laser group velocity plays a crucial role in THz waves generation. However, K is typically assumed to be unity and its…
Ultrashort pulsed lasers (USPL) can produce thin columns of plasma in air via femtosecond filamentation, and these plasmas have been found to generate broadband TeraHertz (THz) and Radio Frequency (RF) radiation. A recent theory argues that…
Mixing the fundamental ($\omega$) and the second harmonic (2$\omega$) waves in gas phase is a widely employed technique for emitting terahertz (THz) pulses. The THz generation driven by bi-chromatic fields can be described by the…
Physics of the plasma rotation driven by biasing in linear traps is analyzed for two limiting cases. The first, relevant for traps with decent plasma parameters, considers the line-tying effects to be responsible for the drive as well as…
The spectrum of terahertz (THz) emission in gases via ionizing two-color femtosecond pulses is analyzed by means of a semi-analytic model and finite-difference-time-domain simulations in 1D and 2D geometries. We show that produced THz…
We investigate terahertz emission from two-color fs-laser-induced microplasmas. Under strongest focusing conditions, microplasmas are shown to act as point-sources for broadband terahertz-to-far-infrared radiation, where the emission…
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…
The propagation of a superintense laser pulse in an underdense, inhomogeneous plasma has been studied numerically by two-dimensional particle-in-cell simulations on a time scale extending up to several picoseconds. The effects of the ion…
As terahertz (THz) frequencies emerge as promising candidates for next-generation wireless networks, accurate characterization of propagation mechanisms in indoor/outdoor environments becomes essential for system design and performance…
The radiation formation length for relativistic particles, $l_c \sim \gamma^2 \lambda$ ($\gamma$ is the Lorentz factor, $\lambda$ is the emitted wavelength), is much lager than the inter-particle distances in many astrophysical…
We investigate to which extend a THz laser pulse can be used to produce field-free molecular orientation at high temperature. We consider laser pulses that can be implemented with the state of the art technology and we show that the…
Magnetized high-energy-density plasmas can often have strong electromagnetic fluctuations whose correlation scale is smaller than the electron Larmor radius. Radiation from the electrons in such plasmas, which markedly differs from both…
For the first time it is shown that for thin metallic films thickness of which not exceed thickness of skin -- layer, the problem of description of surface plasma oscillations allows analytical solution by arbitrary ratio between length of…
An angular distribution of received signals has a significant impact on their spectral and correlational properties. Most of angular dispersion models do not consider antenna patterns. The developed procedure for determining the propagation…
Spintronic THz emitters, consisting of Ta/Co/Pt trilayers patterned into rectangles of lateral size in the 10 ${\mu}$m range, have been integrated in planar electromagnetic antennas of various types (dipole, bow-tie, spiral). Antenna…
Resonant frequencies of the two-dimensional plasma in FETs increase with the reduction of the channel dimensions and can reach the THz range for sub-micron gate lengths. Nonlinear properties of the electron plasma in the transistor channel…
In the widely-studied two-color laser scheme for terahertz (THz) radiation from a gas, the frequency ratio of the two lasers is usually fixed at $\omega_2/\omega_1=$1:2. We investigate THz generation with uncommon frequency ratios. Our…
It is shown, by simulation and theory, that circularly or elliptically polarized terahertz radiation can be generated when a static magnetic (B) field is imposed on a gas target along the propagation direction of a two-color laser driver.…
Considering a realistic situation, where electron-neutral collisions persist in plasma, analytical calculations are carried out for the THz radiation generation by beating of two Skew Cosh-Gaussian (SG) lasers of parameters n & s. The…