Spatial and temporal study of the post-compressed high-power laser pulses for coherent extreme ultraviolet source development

TL;DR

This study compares two post-compression methods for high-power laser pulses, demonstrating their efficiency and effects on beam quality, with implications for developing high-quality extreme ultraviolet sources.

Contribution

It provides a detailed comparison of gas-filled hollow-core fiber and multi-pass cell post-compression techniques, highlighting their efficiencies and impact on beam quality.

Findings

HCF produces 27 fs pulses from 230 fs inputs with >50% efficiency.

MPC achieves 34 fs pulses with >88% efficiency.

HCF acts as a modal filter improving beam quality.

Abstract

We compared the performance of two post-compression techniques, a gas-filled hollow-core fiber (HCF) and a multi-pass cell (MPC), using a high-power ytterbium-doped fiber laser. The HCF produced 27 fs pulses from 230 fs inputs at >50% efficiency, whereas the MPC achieved 34 fs pulses with significantly higher efficiency (>88%). Both results aligned well with numerical simulations. Crucially, spatial wavefront analysis revealed that the HCF acts as a modal filter, improving beam quality, whereas the MPC introduces aberrations through cumulative mirror errors. Furthermore, we characterize the photon flux of high harmonic generation driven by the post-compressed pulses from the HCF and MPC. These finding highlights that post-compression technique based on self-phase modulation is efficient for the intensity boosting of femtosecond laser system, providing opportunities for generating high quality extreme ultraviolet (XUV) sources. In addition, further improvement of spatial wavefront quality is suggested using the HCF as a single compressor or output component of the cascade compressor.