Our general objectives are concerned with the study of atomic and molecular processes and with the transport of charged particles in weakly ionized collision-dominated plasmas. We are devoting our efforts to those problems in gaseous electronics that are relevant to the physics of gas lasers. These devices have numerous applications. We are expanding our studies of gas lasers to the development...

We study high-order harmonic generation (HHG) spectra by a focused truncated Bessel beam versus a Gaussian beam, including macroscopic propagation of the fundamental laser and harmonic fields in the gas medium, with the single-atom-induced dipole response calculated from the recently developed quantitative rescattering theory. We first simulate the HHG spectra of Ar by an 8-fs and 780-nm short ...