Research Paper: Effect of Femtosecond Laser Polarization on The High- Harmonic Generation from Formaldehyde Molecule

Abstract

In this work, we study the interaction of femtosecond laser with formaldehyde molecule and investigate the effect of intensity and angle of laser polarization on the high harmonic generation. The calculation is done with time-dependent density functional theory in three-dimensional real space. The effect of the ellipticity parameter and the role of different orbitals of this molecule on the high harmonic spectrum is investigated, so that the contribution of different orbitals of the formaldehyde molecule in this process can be controlled. The maximum intensity and the maximum width of the high harmonic spectrum are obtained for the ellipticity parameter of 0.15. Also, if the large diameter of the ellipse of laser polarization is along the y-axis, the intensity of the harmonic spectrum is increased, and the reason for this process is discussed by analyzing the time evolution of the population of ionized electrons. In the following, the effect of incident laser polarization on the output attosecond pulse polarization and its width is investigated, which is resulted in the generation of an elliptically polarized attosecond pulse.

Keywords

• high-harmonic generation
• femtosecond laser
• formaldehyde molecule
• molecular orientation
• laser polarization