We demonstrate experimentally that prealigned molecules produce observable spectral redshift or blueshift on the high-order harmonic generation. We distinguish two effects of molecular alignment on the phase modulation of the harmonics; one is from the gradient of alignment degree and the other is the plasma density varied by the molecular alignment. The finding provides an insight on the spectral distribution of molecular harmonics and a method of fine-tuning the harmonic spectrum.
© 2013 Optical Society of America
Atomic and Molecular Physics
Original Manuscript: August 27, 2013
Revised Manuscript: October 14, 2013
Manuscript Accepted: October 17, 2013
Published: November 14, 2013
Peng Peng, Na Li, Jiawei Li, Hua Yang, Peng Liu, Ruxin Li, and Zhizhan Xu, "Spectral modulation of high-order harmonic generation from prealigned CO2 molecules," Opt. Lett. 38, 4872-4875 (2013)