We raise the power from a commercial 10 W frequency comb inside an enhancement cavity and perform multi-photon ionization of gas-phase atoms at 100 MHz for the first time, to the best of our knowledge. An intra-cavity velocity-map-imaging setup collects electron-energy spectra of xenon at rates several orders of magnitude higher than those of conventional laser systems. Consequently, we can use much lower intensities ∼1012W/cm2 without increasing acquisition times above just a few seconds. The high rate and coherence of the stabilized femtosecond pulses are known to be transferred to the actively stabilized cavity and will allow studying purely perturbative multi-photon effects, paving the road towards a new field of precision tests in nonlinear physics.
J. Nauta, J.-H. Oelmann, A. Ackermann, P. Knauer, R. Pappenberger, A. Borodin, I. S. Muhammad, H. Ledwa, T. Pfeifer, and J. R. C. López-Urrutia, “100MHz frequency comb for lowintensity multi-photon studies: intra-cavity velocity-map imaging of xenon”, Opt. Lett. 45, 2156 (2020)
Related to Project: B01