Bound electron nonlinearity beyond the ionization threshold

Abstract

Although high field laser-induced ionization is a fundamental process underlying many applications, there have been no absolute measurements of the nonlinear polarizability of atoms and molecules in the presence of ionization. Such information is crucial, for example, for understanding the propagation of high intensity ultrashort pulses in matter. Here, we present absolute space- and time-resolved measurements of the ultrafast laser-driven nonlinear polarizability in argon, krypton, xenon, nitrogen, and oxygen up to an ionization fraction of a few percent. These measurements enable determination of the non-perturbative bound electron nonlinearity well beyond the ionization threshold, where it is found to be approximately linear in intensity.

References in corpus (11)

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• Ultrashort filaments of light in weakly-ionized, optically-transparent media
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• Higher-order Kerr terms allow ionization-free filamentation in gases
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• Optical nonlinearity in Ar and N${}_2$ near the ionization threshold
• Nonlinear propagation of light in structured media: generalized unidirectional pulse propagation equations
• On the Saturation of the Nonlinear Refractive Index in Atomic Gases
• High-field quantum calculation reveals time-dependent negative Kerr contribution
• Bound electron nonlinearity beyond the ionization threshold
• Precise and accurate measurements of strong-field photoionisation and a transferrable laser intensity calibration standard

Cited by in corpus (8)

• Bound electron nonlinearity beyond the ionization threshold
• Absolute measurement of laser ionization yield in atmospheric pressure range gases over 14 decades
• Full path single-shot imaging of femtosecond pulse collapse in air turbulence
• Pump-probe study of plasma dynamics in gas-filled photonic crystal fiber using counter-propagating solitons
• Second harmonic generation of spatiotemporal optical vortices and conservation of orbital angular momentum
• Simplified single-shot supercontinuum spectral interferometry
• Ionization rate and plasma dynamics at 3.9 micron femtosecond photoionization of air
• Transient-grating single-shot supercontinuum spectral interferometry (TG-SSSI)