Intensity dependence of the H₂⁺ ionization rates in Ti:sapphire laser fields above the Coulomb-explosion threshold

Ionization rates of the hydrogen molecular ion H₂⁺ under linearly polarized pulse of intense laser fields are simulated by direct solution of the fixed-nuclei time-dependent Schrödinger equation for the Ti:sapphire laser lines λ=790 and 800 nm at high intensities starting from just above the Coulomb explosion threshold (i.e., 6.0×10¹³, 1.0×10¹⁴, 3.2×10¹⁴, and 1.4×10¹⁵ W cm⁻²). Results obtained in this research exhibit a high degree of complexity for the R-dependent enhanced ionization rates for the H₂⁺ system in these intense laser fields. The R-dependent ionization peaks move towards small internuclear distances and their structure becomes simpler and smoother with the increase in the intensity of the laser pulse, i.e., with the decrease in the Keldysh parameter. Results obtained in this research are comparable to and even more reliable than the results of other theoretical calculations reported recently and successfully simulate the experimental ionization data.