Multiphoton above-threshold ionisation of xenon at 0.53 and 1.06 m

Abstract

Standard techniques of photoelectron spectrometry have been used to study multiphoton ionisation of xenon. At 0.53 mu m, up to ten-photon ionisation of the 5p shell is detected above the six-photon ionisation threshold for both the Xe+ 2P1/2 and 2P3/2 states. The intensity dependence is compared with the predictions of perturbation theory. The branching ratio 2P3/2:2P1/2 has been measured as a function of the ionisation order. At 1.06 mu m up to 21-photon ionisation has been detected above the eleven-photonionisation threshold.