We report measurements and theoretical simulations of high-order harmonic generation (HHG) in aligned N2molecules using a 1200-nm intense laser field when the generating pulse is perpendicular to the aligning one.Withincreasing laser intensity, the minimum in theHHGspectra first shifts its position and then disappears. Theoreticalsimulations including the macroscopic propagation effects in the medium reproduce these observations and thedisappearance of the minimum is attributed to the additional contribution of HHG from inner orbitals. We alsopredict that the well-known shape resonance in the photoionization spectra of N2 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 theangle between the two lasers increases. No clear evidence of this shape resonance has been reported so far whenusing lasers with different wavelengths. Further experimentation is needed to draw conclusions.
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