Thilo vom Hövel, Franz Huybrechts, Eric Boltersdorf, Christian Wahl, Frank Vewinger, Martin Weitz:
Phys. Rev. A 108, 012821 (2023)
🔓 arXiv:2304.12803 (2023)
Spectroscopy of gases under high-pressure conditions is of interest in various fields such as plasma physics or astrophysics. Recently, it has also been proposed to utilize a high-pressure noble gas environment as a thermalization medium to extend the wavelength range of photon Bose-Einstein condensates to the vacuum-ultraviolet, from the presently accessible visible and near-infrared spectral regimes. In this work, we report on experimental results of two-photon spectroscopy of gaseous and supercritical xenon for pressures as high as 95 bar, probing the transitions from the 5p6 electronic ground state to the 5p56p and 5p56p′ excited state configurations. Aiming at the exploration of possible pumping schemes for future vacuum-ultraviolet photon condensates, we have recorded degenerate two-photon excitation spectra of such dense xenon samples. In further measurements, we have investigated whether irradiation of an auxiliary light field can enhance the reabsorption of the emission on the second excimer continuum of xenon, which is subject to a large Stokes shift. To this end, absorption measurements have been conducted, driving the 5p6→5p56p two-photon transitions non-degenerately.