Extreme Ultraviolet Superfluorescence in Xenon and Krypton

Abstract

We present a comprehensive experimental and theoretical study on superfluorescence in the extreme ultraviolet wavelength regime. Focusing a high-intensity free-electron laser pulse in a cell filled with Xe or Kr gas, the medium is quasi instantaneously population-inverted by inner-shell ionization on the giant resonance followed by Auger decay. On the timescale of 100 ps a macroscopic polarization builds up in the medium, resulting in superfluorescent emission of several Xe and Kr lines in the forward direction. As the number of emitters in the system is increased by either raising the pressure or the pump-pulse energy, the emission shows an exponential growth of over 4 orders of magnitude and reaches saturation. With increasing yield, we observe line broadening, a manifestation of superfluorescence in the spectral domain. Our novel theoretical approach, based on a full quantum treatment of the atomic system and the irradiated field, shows quantitative agreement with the experiment and supports our interpretation.

References in corpus (3)

• Superfluorescence, free-induction decay, and four-wave mixing: propagation of free-electron laser pulses through a dense sample of helium ions
• Quantum theory of superfluorescence based on two-point correlation functions
• Simultaneous measurements of super-radiance at multiple wavelengths from helium excited states: (I) Experiment

Cited by in corpus (7)

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• Dialogue on analytical and ab initio methods in attoscience
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• Generation of Intense Phase-Stable Femtosecond Hard X-ray Pulse Pairs
• Transition between Amplified Spontaneous Emission and Superfluorescence in a longitudinally pumped medium by an X-ray free electron laser pulse
• Time-resolved quantum beats in the fluorescence of helium resonantly excited by XUV radiation
• A Cascade Superradiance Model