Sensitivity of propagation and energy deposition in femtosecond filamentation to the nonlinear refractive index

Abstract

The axial dependence of femtosecond filamentation in air is measured under conditions of varying laser pulsewidth, energy, and focusing f-number. Filaments are characterized by the ultrafast z-dependent absorption of energy from the laser pulse and diagnosed by measuring the local single cycle acoustic wave generated. Results are compared to 2D+1 simulations of pulse propagation, whose results are highly sensitive to the instantaneous (electronic) part of the nonlinear response of $N_2$ and $O_2$. We find that recent measurements of the nonlinear refractive index ($n_2$) in [J.K. Wahlstrand et al., Phys. Rev. A. 85, 043820 (2012)] provide the best match and an excellent fit between experiments and simulations.

arXiv comment15 pages, 4 figures

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Cited by in corpus (11)

• Spatio-temporal optical vortices
• Measurement of the nonlinear refractive index of air constituents at mid-infrared wavelengths
• Generation of long-lived underdense channels using femtosecond filamentation in air
• Spectral dynamics of THz pulses generated by two-color laser filaments in air: The role of Kerr nonlinearities and pump wavelength
• Terahertz pulse generation by two-color laser fields with circular polarization
• Energy deposition from focused terawatt laser pulses in air undergoing multifilamentation
• Filamentation of Mid-IR pulses in ambient air in the vicinity of molecular resonances
• Efficient self-compression of ultrashort UV pulses in air-filled hollow-core photonic crystal fiber
• Atmospheric aerosol clearing by femtosecond filaments
• Full path single-shot imaging of femtosecond pulse collapse in air turbulence
• Plasma dynamics of a laser filamentation-guided spark