# Ab-initio calculations of laser-atom interactions reveal harmonics feedback during macroscopic propagation

## TL;DR

This paper presents a coupled quantum-classical model to simulate ultrashort laser pulse propagation in atomic media, revealing how self-generated harmonics influence ionization and harmonic yield during macroscopic propagation.

## Contribution

It introduces a novel ab initio coupled model that captures the feedback of generated harmonics on laser propagation and ionization processes.

## Key findings

- Harmonics up to order 11 significantly affect pulse propagation.
- Generated harmonics influence ionization probability.
- Feedback mechanisms alter harmonic yields during propagation.

## Abstract

We couple the full 3D ab initio quantum evolution of the light pulse polarization in interaction with an atom with a propagation model to simulate the propagation of ultrashort laser pulses over macroscopic dimensions, in the presence of self-generated harmonics up to order 11. We evidence a clear feedback of the generated harmonics on propagation, with an influence on the ionization probability as well as the yield of the harmonic generation itself.