A Raman-delayed nonlinearity for elliptically polarized ultrashort optical pulses

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.

Automated summary

This paper addresses the role of delayed Kerr nonlinearity associated with stimulated rotational Raman scattering on intense ultrashort two-color filaments with elliptical polarization in gases, and examines its impact on the generation of optical frequencies and terahertz frequencies. The study finds that the nonlinearity associated with stimulated Raman scattering strongly affects the dynamics of laser filaments and modifies the overall pulse spectral content, particularly altering the THz spectra during filamentation propagation. Differences between linearly and circularly polarized two-color pump pulses are discussed.