Calculations of resonant multiphoton population transfer in potassium atoms at long wavelengths

Mette B. Gaarde, Louisiana State University
Kenneth J. Schafer, Louisiana State University


The response of the potassium atoms to midinfrared radiation was used to study the interplay between resonant multiphoton population transfer and the field ionizations. The amount of population transferred to the excited state was found as a function of wavelength and intensity by using wavelengths close to three of five photon resonance. The amount of resonance remaining in the 4p state at the end of the laser pulse shows a sensitivity to the sign of the laser pulse, whereas the total amount of ionization does not.