Related papers: Spectrum Phase and Constraints on THz-Optical klys…
Observations in the sub-THz range of large solar flares have revealed a mysterious spectral component increasing with frequency and hence distinct from the microwave component commonly accepted to be produced by gyrosynchrotron (GS)…
Self consistent analytic and numeric design for a set of electron guns with a high beams quality to be used in high power Ka-band klystrons are presented in this paper. The set of electron guns can be used in the high power Ka-band…
We present a numerical study on plasma generation of THz radiation utilizing multiple light pulses of various wavelengths in an optical scheme that is readily achievable in a tabletop environment. To achieve coherent THz emission it is…
The high-performance operation of fourth-generation synchrotron light sources critically depends on harmonic cavities (HCs) to alleviate statistical collective effects through bunch lengthening. Active HCs are preferred over passive ones…
The high peak current required in free-electron lasers (FELs) is realized by longitudinal compression of the electron bunches to sub-picosecond length. In this paper, a frequency-domain diagnostic method is described that is capable of…
We report on terahertz (THz) radiation under electrical pumping from a degenerate semiconductor possessing an electron accumulation layer. In InN, the random grating formed by topographical defects provides high-efficiency coupling of…
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…
We propose a novel amplification mechanism for high harmonic generation (HHG) in solids by leveraging bandgap engineering with momentum k-gaps. By constructing a simple diatomic lattice featuring balanced, alternating gain and loss…
We propose and demonstrate a novel method to produce few-femtosecond electron beam with relatively low timing jitter. In this method a relativistic electron beam is compressed from about 150 fs (rms) to about 7 fs (rms, upper limit) with…
Planar microcavities with distributed Bragg reflectors (DBRs) host, besides confined optical modes, also mechanical resonances due to stop bands in the phonon dispersion relation of the DBRs. These resonances have frequencies in the…
Terahertz (THz) generation by optical rectification (OR) using tilted-pulse-fronts is studied. One-dimensional (1-D) and 2-D spatial models, which simultaneously account for (i) the nonlinear coupled interaction of the THz and optical…
With a low emittance and short-bunch electron beam at a high repetition rate realized by a superconducting linac, stimulated excitation of an optical cavity at the terahertz spectrum range has been shown. The electron beam passed through…
There are implementations and proposals for using microwave or optical radiation for electron acceleration, undulation, deflection, and spatial as well as temporal focusing. Using terahertz (THz) radiation in such applications can be…
In this paper, a simple method is proposed to extend the photon energy range of a soft x-ray self-seeding free-electron laser (FEL). A normal monochromator is first applied to purify the FEL spectrum and provide a coherent seeding signal.…
Contribution of plasma oscillation to the broadband terahertz emission is revealed by interacting two-color laser pulses with a supersonic jet of nitrogen molecules. Temporal and spectral shifts of THz waves are observed as the plasma…
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…
The possibility of enhancing the radiation power and monochromaticity by optically induced photonic crystal in the superconducting cavity is proposed and investigated. In such a structure, by periodically irradiating the stacked Josephson…
Crab crossing scheme is an essential collision scheme to achieve high luminosity for the future colliders with large crossing angles. However, when bunch length of one or both colliding beams is comparable with the wavelength of the crab…
We discuss simulations and experiments on creating micro-bunch beams for generating narrow band THz radiation at the Fermilab Accelerator Science and Technology (FAST) facility. The low-energy electron beamline at FAST consists of a…
The terahertz (THz) frequency range is key to study collective excitations in many crystals and organic molecules. However, due to the large wavelength of THz radiation, the local probing of these excitations in smaller crystalline…