Effect of nuclear motion on high-order harmonic generation of H${}_2^{+}$ in intense ultrashort laser pulses

Abstract

High-order harmonic generation is investigated for H${}_2^{+}$ and D${}_2^{+}$ with and without Born-Oppenheimer approximation by numerical solution of full dimensional electronic time-dependent Schrödinger equation under 4-cycle intense laser pulses of 800 nm wavelength and $I$=4, 5, 7, 10 $\times 10^{14}$ W$/$cm${}^2$ intensities. For most harmonic orders, the intensity obtained for D${}_2^{+}$ is higher than that for H${}_2^{+}$, and the yield difference increases as the harmonic order increases. Only at some low harmonic orders, H${}_2^{+}$ generates more intense harmonics compared to D${}_2^{+}$. The results show that nuclear motion, ionization probability and system dimensionality must be simultaneously taken into account to properly explain the isotopic effects on high-order harmonic generation and to justify experimental observations.

7 pages, 5 figures

References in corpus (1)

• Detailed instantaneous ionization rate of H${}_2^{+}$ in intense laser field

Cited by in corpus (2)

• Full-dimensional treatment of short-time vibronic dynamics in molecular high-harmonics generation process in methane
• Understanding molecular harmonic emission at relatively long intense laser pulses: Beyond the Born-Oppenheimer approximation