Related papers: THz generation by dual-color pulse in prealigned m…
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…
Various schemes are presented for the generation of circularly polarized molecular high-order harmonic generation (MHOHG) from molecules. In particular it is shown that combinations of counter-rotating circularly polarized pulses produce…
High-order harmonic generation (HHG) in the relativistic regime is employed to obtain zeptosecond pulses of $\gamma$-rays. The harmonics are generated from atomic systems in counterpropagating strong attosecond laser pulse trains of linear…
We studied the effects of cryogenic cooling of a 2-[3-(4-hydroxystyryl)-5, 5-dimethylcyclohex-2-enylidene] malononitrile (OH1) crystal on the generation of broadband THz pulses via collinear optical rectification of 1350 nm femtosecond…
We present a theoretical model of high-harmonic generation from diatomic molecules. The theory includes effects of alignment as well as nuclear motion and is used to predict results for N$_2$, O$_2$, H$_2$ and D$_2$. The results show that…
We demonstrate a High-Harmonic-Generation scheme which offers control over the bandwidth of the spectral peaks. The scheme uses a vectorial two-color driver with close central frequencies, generated by spectrally splitting a…
Generation of electromagnetic radiation near the second harmonic of the plasma frequency during the injection of an electron beam into a rippled-density plasma channel is investigated using both analytical theory and particle-in-cell…
In a superconductor the third-harmonic generation (THG) of a strong THz pulse is enhanced below Tc by the resonant excitation of lattice-modulated charge fluctuations (LCF), which modulate the response according to the polarization of the…
The generation of pulsed polarization entangled photon pair has been realized using type-I phase matching in the spontaneous parametirc downconversion process in a space cascaded two-crystal geometry. The optical axes of the crystal are…
We develop the microscopic theory of a terahertz (THz) laser based on the effects of resonant tunneling in a double quantum well heterostructure embedded in both optical and THz cavities. In the strong coupling regime the system hosts…
We show that high-order harmonics generated from molecules by intense laser pulses can be expressed as the product of a returning electron wave packet and the photo-recombination cross section (PRCS) where the electron wave packet can be…
We theoretically demonstrate the possibility to tune the temporal waveform of optical unipolar pulses upon their coherent interaction with a multi-level resonant medium. This is achieved through the coherent control of the response of a…
A thin and dense plasma layer is created when a sufficiently strong laser pulse impinges on a solid target. The nonlinearity introduced by the time-dependent electron density leads to the generation of harmonics. The pulse duration of the…
Nonlinear THz photonics is probably the last frontier of nonlinear optics. The strength of both the electric and the magnetic fields of these ultrashort low frequency light bunches opens the way to exciting science and applications.…
High harmonic generation (HHG) is a manifestation of the strongly nonlinear response of matter to intense laser fields and has, as the basis for coherent XUV sources a variety of applications. Recently, HHG from atoms in a phase and…
Terahertz (THz) sciences and technologies have contributed to a rapid development of a wide range of applications and expanded the frontiers in fundamental science. Spintronic terahertz emitters offer conceptual advantages since the spin…
High-power, continuously tunable narrowband terahertz (THz) sources are essential for advancing nonlinear optics, THz-driven material dynamics, and ultrafast spectroscopy. Conventional techniques typically impose a trade-off between pulse…
Nonlinear terahertz (THz) spectroscopy relies on the interaction of matter with few-cycle THz pulses of electric field amplitudes up to megavolts/centimeter (MV/cm). In condensed-phase molecular systems, both resonant interactions with…
We investigate the process of circularly polarized high harmonic generation in molecules using a bicircular laser field. In this context, we show that molecules offer a very robust framework for the production of circularly polarized…
This is a brief overview of the main physical ideas for application of field effect transistors for generation and detection of TeraHertz radiation. Resonant frequencies of the two-dimensional plasma oscillations in FETs increase with the…