Related Experiment Video
Updated: Jun 14, 2026

An Experimental Protocol for Femtosecond NIR/UV - XUV Pump-Probe Experiments with Free-Electron Lasers
Published on: October 23, 2018
Phase measurement of resonant two-photon ionization in helium
M Swoboda1, T Fordell, K Klünder
1Department of Physics, Lund University, P.O. Box 118, 22100 Lund, Sweden.
Abstract:
We study resonant two-color two-photon ionization of helium via the 1s3p (1)P(1) state. The first color is the 15th harmonic of a tunable Ti:sapphire laser, while the second color is the fundamental laser radiation. Our method uses phase-locked high-order harmonics to determine the phase of the two-photon process by interferometry. The measurement of the two-photon ionization phase variation as a function of detuning from the resonance and intensity of the dressing field allows us to determine the intensity dependence of the transition energy.
Related Concept Videos
Double Resonance Techniques: Overview
Spin decoupling is usually achieved by...
Emission Spectra
Chemical Ionization (CI) Mass Spectrometry
Atomic Emission Spectroscopy: Lab
The de Broglie Wavelength
Mass Analyzers: Common Types

