相关论文: Direct observation of spatio-temporal dynamics of …
At KARA, the KArlsruhe Research Accelerator of the KIT synchrotron, the so called short bunch operation mode allows the reduction of the bunch length down to a few picoseconds. The micro- bunching instability resulting from the high degree…
Intense, single-cycle terahertz (THz) pulses offer a promising approach for understanding and controlling the properties of a material on an ultrafast time scale. In particular, resonantly exciting phonons leads to a better understanding of…
Recent solar flare observations in the sub-THz range have provided evidence of a new spectral component with fluxes increasing for larger frequencies, separated from the well-known microwave emission that maximizes in the GHz range.…
A laser pulse composed of a fundamental and an appropriately phased second harmonic can drive a time-dependent current of photoionized electrons that generates broadband THz radiation. Over the propagation distances relevant to many…
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…
Single-shot recording of terahertz electric signals has recently become possible at high repetition rates, by using the photonic time-stretch electro-optic sampling (EOS) technique. However the moderate sensitivity of time-stretch EOS is…
When a relativistic, femtosecond laser pulse enters a waveguide, the pulse energy is coupled into waveguide optical modes. The longitudinal laser field effectively accelerates electrons along the axis of the channel, while the asymmetric…
The use of terahertz (THz) and optical radiation for electron acceleration and manipulation of electron bunches has progressed over the last decade to a level where practical devices for THz guns, THz and optical acceleration modules and a…
Terahertz (THz) generation by optical rectification in LiNbO$_3$ (LN) is a widely used technique for generating intense THz radiation. The spatiotemporal characterization of THz pulses from these sources is currently limited to far-field…
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…
The paper considers the process of Thomson scattering of coherent diffraction radiation (CDR) produced by the preceding bunch of the accelerator on one of the following bunches. It is shown that the yield of scattered hard photons is…
Accelerator-based terahertz (THz) radiation has been expected to realize a high-power broadband source. Employing a low-emittance and short-bunch electron beam at a high repetition rate, a scheme of coherent diffraction-radiation in an…
We report terahertz (THz) second harmonic generation (SHG) in superconductors (SC) with inversion symmetric equilibrium states that forbid even-order nonlinearities. Such SHG signal is observed in single-pulse emission by periodic driving…
We study coherent synchrotron radiation (CSR) in a perfectly conducting vacuum chamber of rectangular cross section, in a formalism allowing an arbitrary sequence of bends and straight sections. We apply the paraxial method in the frequency…
Terahertz (THz) generation via photomixing on photoconductive antenna using twin delayed chirped pulses provides a long THz pulse with a narrow bandwidth. To generate a long pulse with broad bandwidth, we propose a new method that combines…
We investigate influence on the storage ring beam dynamics of the coherent Synchrotron Radiation (SR) self fields produced by an electron bunch. We show that the maximum energy gain in the RF cavity must far exceed the energy loss of…
A new solar burst emission spectral component has been found showing sub-THz fluxes increasing with frequency, spectrally separated from the well known microwave component. Rapid pulsations are found present in all events observed at the…
Coherent synchrotron radiation (CSR) is crucial for the development of powerful ultrashort light sources. We present a mechanism for generating CSR in the form of generalised superradiance, based on surface plasmon polaritons (SPPs), which…
X-ray-induced carrier dynamics in silicon and gallium arsenide were investigated through intensity variations of transmitted terahertz (THz) pulses in the pico to microsecond time scale with X-ray free-electron laser and synchrotron…
For the purposes of measuring the high-frequency complex conductivity of correlated-electron materials at low temperatures and high magnetic fields, a method is introduced for performing coherent time-domain terahertz spectroscopy directly…