We have studied the polarization and ellipticity of high-order harmonics from nitrogen molecules using the time-dependent density functional theory. The results of our numerical calculations are in excellent agreement with the data of recent experiments. The theoretical analysis of our results reveals that at least three contributions, namely those from the HOMO, the HOMO-1, and the HOMO-2 orbitals, contribute to the observed high harmonic spectra. Furthermore, we confirm that a proper account of the distribution of the alignment in the molecular ensemble is necessary to obtain agreement with the experimental data.
© 2014 Optical Society of America
Atomic and Molecular Physics
Original Manuscript: November 21, 2013
Revised Manuscript: January 25, 2014
Manuscript Accepted: January 27, 2014
Published: March 7, 2014
Yuqing Xia and Agnieszka Jaroń-Becker, "Multielectron contributions in elliptically polarized high-order harmonic emission from nitrogen molecules," Opt. Lett. 39, 1461-1464 (2014)