Spatially homogeneous few-cycle compression of Yb lasers via all-solid-state free-space soliton management

TL;DR

This paper demonstrates a novel all-solid-state free-space compressor that achieves efficient, high-quality, few-cycle pulse compression of Yb laser pulses with exceptional spatio-spectral homogeneity and stability, suitable for ultrafast science applications.

Contribution

The work introduces a new method for spatially homogeneous few-cycle pulse compression using soliton modes in layered Kerr media, achieving record efficiency and quality in all-solid-state free-space compressors.

Findings

Compressed 170 fs pulses to ~9.2 fs at 1030 nm

Achieved spatio-spectral homogeneity of ~0.87

High efficiency of >50% for pulse compression

Abstract

The high power and variable repetition rate of Yb femtosecond lasers make them very attractive for ultrafast science. However, for capturing sub-200 fs dynamics, efficient, high-fidelity, and high-stability pulse compression techniques are essential. Spectral broadening using an all-solid-state free-space geometry is particularly attractive, as it is simple, robust, and low-cost. However, spatial and temporal losses caused by spatio-spectral inhomogeneities have been a major challenge to date, due to coupled space-time dynamics associated with unguided nonlinear propagation. In this work, we use all-solid-state free-space compressors to demonstrate compression of 170 fs pulses at a wavelength of 1030nm from a Yb:KGW laser to ~9.2 fs, with a highly spatially homogeneous mode. This is achieved by ensuring that the nonlinear beam propagation in periodic layered Kerr media occurs in soliton modes and confining the nonlinear phase through each material layer to less than 1.0 rad. A remarkable spatio-spectral homogeneity of ~0.87 can be realized, which yields a high efficiency of >50% for few-cycle compression. The universality of the method is demonstrated by implementing high-quality pulse compression under a wide range of laser conditions. The high spatiotemporal quality and the exceptional stability of the compressed pulses are further verified by high-harmonic generation. This work represents the highest efficiency and the best spatio-spectral quality ever achieved by an all-solid-state free-space pulse compressor for few-cycle-pulse generation.