Intensity dependence of multiple orbital contributions and shape resonance in high-order harmonic generation of aligned N${}_2$ molecules}

Abstract

We report measurements and theoretical simulations of high-order harmonic generation (HHG) in aligned N${}_2$ molecules using a 1200-nm intense laser field when the generating pulse is perpendicular to the aligning one. With increasing laser intensity, the minimum in the HHG spectra first shifts its position and then disappears. Theoretical simulations including the macroscopic propagation effects in the medium reproduce these observations and the disappearance of the minimum is attributed to the additional contribution of HHG from inner orbitals. We also predict that the well-known shape resonance in the photoionization spectra of N${}_2$ should exist in the HHG spectra. It is most clearly seen when the generating laser is parallel to the aligning one, and disappears gradually as the angle between the two lasers increases. No clear evidence of this shape resonance has been reported so far when using lasers with different wavelengths. Further experimentation is needed to draw conclusions.

8 pages, 4 figures

References in corpus (8)

• Accurate retrieval of structural information from laser-induced photoelectron and high-harmonic spectra by few-cycle laser pulses
• Quantitative Rescattering Theory for high-order harmonic generation from molecules
• Self-probing of Molecules with High Harmonic Generation
• Medium propagation effects in high harmonic generation of Ar and N${}_2$
• Probing molecular frame photoionization via laser generated high-order harmonics from aligned molecules
• Uncovering multiple orbitals influence in high harmonic generation from aligned N${}_2$
• Separation of Target Structure and Medium Propagation Effects in High-Harmonic Generation
• Analysis of effects of macroscopic propagation and multiple molecular orbitals on the minimum in high-order harmonic generation of aligned CO${}_2$

Cited by in corpus (9)

• Multi-channel Electronic and Vibrational Dynamics in Polyatomic High-order Harmonic Generation
• High-order-harmonic generation in benzene with linearly and circularly polarised laser pulses
• Multielectron effects in high harmonic generation in N2 and benzene: simulation using a non-adiabatic quantum molecular dynamics approach for laser-molecule interactions
• Molecular orbital tomography beyond the plane wave approximation
• High-order harmonic generation from field-distorted orbitals
• Topology of surfaces for molecular Stark energy, alignment and orientation generated by combined permanent and induced electric dipole interactions
• Supersymmetry and eigensurface topology of the spherical quantum pendulum
• Symmetric Tops Subject to Combined Electric Fields: Conditional Quasi-Solvability via the Quantum Hamilton-Jacobi Theory
• Directional properties of polar paramagnetic molecules subject to congruent electric, magnetic and optical fields