Control of spatiotemporal localization of infrared pulses in gas-filled capillaries using weak ultraviolet pulses

TL;DR

This paper presents a numerical scheme to control infrared pulse localization in gas-filled capillaries by using a weak ultraviolet pulse, enhancing interaction length and potential high-field applications.

Contribution

It introduces a novel control method employing a weak UV pulse with negative delay to manipulate pulse propagation in capillaries, surpassing traditional tuning approaches.

Findings

Weak UV pulse causes significant red-shift of the main IR pulse.

The control scheme extends the effective interaction length of pulses.

Potential improvements in high-order harmonic generation applications.

Abstract

Manipulation of intense pulse propagation in gas-filled capillaries is desirable for various high-field applications. Tuning the parameters of the driving laser pulse and the working gas is the conventional approach, and it provides limited capability of control. Here we demonstrate through numerical simulations a practical scheme to control the propagation of intense pulses. A weak ultraviolet pulse is launched into a capillary with a negative delay with respect to a main infrared pulse. The pulses begin to temporally overlap due to dispersion. As the main pulse self-compresses, the control pulse is strongly red-shifted due to cross-phase modulation. The frequency shifts of the two pulses mitigate pulse walk-off and allow an efficient coupling, substantially extending the effective interaction length. This interesting phenomenon may benefit applications such as high-order harmonic generation.