Impact of material properties on the nonlinear spectral broadening in thin solid media

We present the post-compression of 25 fs pulses with a flat-top beam profile in different nonlinear media. Fused silica, sapphire, and YAG plates were tested for spectral broadening and compressibility while measuring the spatio-spectral properties of the broadened pulses. To our best knowledge, such systematic investigation has not yet been carried out. The near- and far-field profiles show that no significant wavefront distortion occurred during the nonlinear propagation but the spatio-spectral homogeneity has a strong correlation with the material characteristics and the accumulated B integral. A series of numerical simulations were also conducted to have deeper insight on the broadening process and the impact of the material properties. The theoretical model also reveals the limitations of compressibility in the single thin plate arrangement and it can support the optimization of future, high-energy experiments. • The spatio-spectral homogeneity depends on the material properties • The maximum compression factor is limited regardless of the material or intensity • Compression quality correlates with the nonlinear propagation length • Input pulse parameters determine the optimal material thickness