Influences of different gases on the terahertz radiation based on the application of two-color laser pulses

Abstract

In this work, using a two-dimensional Particle In Cell-Monte Carlo Collision simulation method, a comparative study is performed on the influences of different types of atomic and molecular gases at various background gas pressures on the generation of broadband and intense Terahertz (THz) radiation via the application of two-color laser pulses. These two modes are focused into Argon (Ar), Xenon (Xe), Nitrogen (N2), Oxygen (O2), and air as the background gaseous media and the plasma channel is created. It is observed that the THz radiation emission dramatically changes due to the propagation effects. A wider THz pulse is emitted from the formed plasma channel at the higher gas pressures. The significant effects of the propagation features of the emitted THz pulse on its energy at the longer lengths of the plasma channel are observed.

THz radiation generation via the interaction of two‐colour ultra‐short laser pulses with SO2 and NH3 gases

“…Moreover, though the generated current density from NH 3 at higher laser pulse durations is higher than with SO 2 molecules, these molecules generate THz electric fields with amplitudes lower than those of SO 2 molecules. It must be noted that for the considered laser pulse durations, the temporal variation of generated THz electric field agrees with the experimental and theoretical findings by other researchers …”

“…This is due to the increase in the generated current density at higher laser beam waists. For the considered laser pulse waists, the temporal variations of generated THz electric field are in agreement with the experimental and theoretical findings by other researchers …”

“…This is due to the fact that the trapezoidal pulse shape has the capability to generate much higher current densities (see Figure ). For the considered laser pulse shapes, the temporal variation of the generated THz electric field is in good agreement with the experimental and theoretical findings by other researchers . On the other hand, the spectra of generated THz radiation with all the considered laser pulse shapes are presented in Figure .…”

“…For NH 3 and SO 2 , SFIE is 25.1 and 21.16 eV, respectively . This is higher than that of other atoms and molecules such as Ar (11.87 eV), Xe (9.08 eV), diatomic hydrogen molecules (0.824), and triatomic water molecules (1.88 eV) . This is reflected in the increased laser energy required for the electron tunnelling ionization.…”

THz Radiation Generation via the Interaction of Ultra‐short Laser Pulses with the Molecular Hydrogen Plasma

“…Study of the broadband and high power Terahertz (THz) radiation generation via the incident laser pulses with the intensities lower than 10 15 W/cm 2 in different gaseous media is reported extensively [1][2][3][4][5][6][7][8]. On the other hand, for the incident laser pulses with the higher intensities, i. e., I >10 15 W/cm 2 , fast ionization of the gas molecules and atoms, however, limits the THz pulse generation.…”