Related papers: Generation of high-quality terahertz OAM mode base…
THz pulses are generated from femtosecond pulse-excited ferromagnetic/nonmagnetic spintronic heterostructures via inverse spin Hall effect. The contribution from ultrafast demagnetization/remagnetization is extremely weak, in the…
We describe a novel approach for generating light beams that carry orbital angular momentum (OAM) by means of total internal reflection in an isotropic medium. A continuous space-varying cylindrically symmetric reflector, in the form of…
Recently, photons have been observed to possess transverse orbital angular momentum (OAM); however, it is unclear as whether they can hold a transverse OAM higher than 1. Here, we theoretically and experimentally demonstrate that high-order…
Coherent light with orbital angular momentum (OAM) is of great interest, and more recently, OAM light generation by coupling a relativistic electron beam with a Gaussian mode laser pulse at the high harmonics of a helical undulator has been…
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…
Ultrarelativistic vortex leptons with intrinsic orbital angular momenta (OAM) have important applications in high energy particle physics, nuclear physics, astrophysics, etc. However, unfortunately, their generation still poses a great…
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…
Diffraction of a relativistically-strong light can produce high-order harmonics via the relativistic oscillating window mechanism. In this process, the characteristics of the 2D electron dynamics at the diffraction screen can be imprinted…
Optical vortex beams are profiled as helical wavefronts with a phase singularity carrying an orbital angular momentum (OAM) associated with their spatial distribution. The transverse intensity distribution of a conventional optical vortex…
We theoretically study the generation of terahertz (THz) radiation by two-color filamentation of ultrashort laser pulses with different wavelengths. We consider wavelengths in the range from 0.6 to 10.6 $\mu$m, thus covering the whole range…
Terahertz (THz) time-domain emission spectroscopy was performed on layered 2H-MoSe2 and 2H-WSe2. The THz emission shows an initial cycle attributed to surge currents and is followed by oscillations attributed to coherent interlayer phonon…
We show that coherently driven atomic or molecular media potentially yield strong controllable short pulses of THz radiation. The method is based on excitation of maximal quantum coherence in a gas medium by optical pulses and coherent…
As the traditional resources (frequency, time, space, etc.) are efficiently utilized, it becomes more and more challenging to satisfy the ever-lasting capacity-growing and users-boosting demand in wireless networks. Recently, the…
We perform a joint measurement of terahertz waves and high-order harmonics generated from noble atoms driven by a fundamental laser pulse and its second harmonic. By correlating their dependence on the phase-delay of the two pulses, we…
The frequency and orbital angular momentum (OAM) are independent physical properties of light that both offer unbounded degrees of freedom. However, creating, processing, and detecting high-dimensional OAM states have been a pivot and…
We propose a scheme to controllably convert the wavefront of an arbitrary incident beam into a helical one by compact transformation slabs, thus enabling the output beam to carry desirable orbital angular momentum (OAM). First, based on…
We propose a method based on the slice energy spread modulation to generate strong subpicoseond density bunching in high-intensity relativistic electron beams. A laser pulse with periodic intensity envelope is used to modulate the slice…
Among the most promising terahertz (THz) radiation devices, gyrotrons can generate powerful THz-wave radiation in an open resonant structure. Unfortunately, such an oscillation using high-Q axial mode has been theoretically and…
We propose an effective scheme for the generation of intense coherent extreme ultraviolet light beams carrying orbital angular momentum (OAM). The light is produced by a high-gain harmonic-generation free-electron laser (FEL), seeded using…
In fluids, vortices form at boundaries between flows of different velocities. Here, we show that pulsed electromagnetic waves form spatiotemporal vortices when light straddles media of different phase velocities. When the resulting relative…