Laser filamentation in molecular gases: Single-shot visualization of a long-range plasma and precise modeling including alignment-dependent ionization
Phys. Rev. A 114, 023518 – Published 24 August, 2026
DOI: https://doi.org/10.1103/zfk9-lptj
Abstract
We report the experimental single-shot visualization and precise modeling of femtosecond laser filamentation in molecular gases and air. Experimentally, we control and enhance laser filamentation using rotational Raman effects by varying the pump-pulse duration and employ single-shot multiobject plane imaging to directly visualize long-range plasma channels and measure the associated plasma density. We compare experiments with nonlinear envelope equation simulations incorporating an alignment-dependent molecular Perelomov-Popov-Terent'ev ionization model, wherein Raman-induced molecular alignment dynamically modulates the ionization rate during filamentation. This approach provides a more accurate ionization model than commonly used atomic ionization approximations. Our work not only demonstrates robust single-shot visualization of filamentation but also highlights that alignment-dependent ionization is important for a comprehensive understanding of long-range filamentation in molecular gases and air.
