A Raman-delayed nonlinearity for elliptically polarized ultrashort optical pulses

Alexandre Stathopulos (1) , Stefan Skupin (2) , Luc Bergé (1)

1 LMCE - Laboratoire Matière sous Conditions Extrêmes
2 ILM - Institut Lumière Matière [Villeurbanne]

We address the role of the delayed Kerr nonlinearity associated with stimulated rotational Raman scattering on the propagation of intense ultrashort two-color filaments with elliptical polarization in gases and examine its impact on the generation of optical frequencies as well as terahertz frequencies. We find that in air the nonlinearity associated with stimulated Raman scattering strongly impacts the dynamics of the laser filaments and modifies the overall pulse spectral content. In particular, it alters the THz spectra upon propagation in the filamentation regime. Differences between linearly and circularly polarized two-color pump pulses are discussed.

Mots clés: nonlinear optics ultrashort laser pulses terahertz pulse generation; nonlinear optics; ultrashort laser pulses; terahertz pulse generation

Domaines: Physique des plasmas [physics.plasm-ph]

Alexandre Stathopulos, Stefan Skupin, Luc Bergé. A Raman-delayed nonlinearity for elliptically polarized ultrashort optical pulses. The European Physical Journal. Special Topics, 2023, 232 (13), pp.2285-2292. ⟨10.1140/epjs/s11734-022-00671-x⟩. ⟨hal-03872394⟩