Fig. 2: Photoelectron kinetic energy spectra due to two-photon ionization of xenon.
From: Temporal characterization of tunable few-cycle vacuum ultraviolet pulses
a, Energy level diagram of xenon, where IP denotes the ionization potential, showing the two possible ionization channels and the lower and upper bounds for the spectrum of the VUV pulse that can be characterized by xenon. A schematic of the resulting kinetic energy spectrum is shown to the right. Ionization producing the 5p5 2P3/2 state can occur either through direct non-resonant two-photon ionization or through two-photon excitation of an AIS converging on the 5p5 2P1/2 state. Ionization producing the 5p5 2P1/2 state is only possible through direct non-resonant two-photon excitation above the 5p5 2P1/2 threshold. b,c Measured kinetic energy spectra corresponding to the measured eFROG traces in Fig. 1a,b, respectively.
