Understanding GHz surface acoustic waves (SAWs) is critical for advancing nondestructive testing and material characterization in applications like semiconductor wafers and optical crystals. Traditional SAW measurement methods often rely on time-consuming point-based techniques, requiring multiple scans to capture angularly resolved wave propagation. This study employs a fast, full-field imaging approach using ultrafast pump–probe microscopy with subpicosecond infrared laser pulses in the ablation regime. This method captures angular propagation velocities of Rayleigh SAWs and high-velocity pseudo-SAWs in fused silica and x-cut quartz. Reflectivity modulations were recorded using a high-resolution sCMOS camera, enabling an observation of wavefront dynamics over a time delay range of 6–11.5 ns. The results matched finite element simulations, achieving relative errors between 2–5%. From the measured wave velocities, key material parameters such as Young’s modulus and Poisson’s ratio were derived in excellent agreement with literature values. This technique demonstrates potential for faster, accurate material characterization.

Despite decades of research on laser-induced-periodic-surface-structures (LIPSS) establishing the role of inhomogeneous energy absorption, temperature gradients, and melt-flow dynamics, material-specific feasibility of LIPSS formation on metals remain incompletely understood. Current theories attribute differences to thermophysical properties and fluid motion, assuming universal optical mechanisms. However, we identified an overlooked factor: material-specific single-pulse morphology.

Through comparative pulse-to-pulse analysis of aluminium and stainless steel, we observed the development of LIPSS on steel, while Al developed a chaotic surface morphology regardless of the pulse number. Using near-field simulations of measured atomic-force-microscopy profiles, we revealed that the roughened surface of steel develops periodic intensity distributions for subsequent pulses, leading to selective ablation for LIPSS formation. Contrary, aluminium’s rougher surface morphology induces incoherent scattering, leading to chaotic intensity distribution, explaining the lack of LIPSS regardless of thermal response.

By addressing the significant influence of material-specific single-pulse morphology, we propose a new pathway for optimizing LIPSS formation.

Time-resolved digital holography is a powerful technique for investigating surface dynamics during laser deep engraving, particularly the emergence of surface roughness components in the frequency domain. These components, whose underlying mechanisms remain poorly understood, significantly influence engraving outcomes. By employing time-resolved digital holography, we gain insights into the ablation dynamics, including the behavior of ejected particles and the resulting shockwaves. Furthermore, this method reveals the interplay between these dynamics and subsequent laser pulses interacting with the sample surface. Our study aims to elucidate the processes contributing to surface roughness development, offering a deeper understanding of the physical phenomena involved. These findings have the potential to improve precision and control in laser deep engraving applications, advancing both industrial and scientific practices.

Long standing open questions in ultrashort pulse laser processing include: What are the physical limits of ablation efficiency in air and liquid? What are the mechanisms of LIPSS formation and the incubation effect? With pump-probe experiments and time-resolved simulations we validate that a mix of spallation and phase explosion leads to the highest achievable ablation efficiency in air, which lies close to the energetics of evaporation, Further we prove with pump-probe microscopy that the redeposition of the spallation layer in liquid is supressing efficiency to about 20% of the air value. Finally by a combination of AFM and FDTD simulations we demonstrated that constructive coherent scattering from the ablation crater nanomorphology creates local field enhancements and surface plasmons which in return generate low frequency LIPPS by selective local ablation. In parallel local field enhancement is also one important contribution to incubation.

X-ray microscopy (XRM) is revolutionizing materials development, exploration, and failure analysis due to its non-destructive imaging and high resolution down to 50 nm. However, preparing cylindrical XRM samples with several tens of microns diameters poses significant challenges. Traditional methods like Focused Ion Beam (FIB) have mainly been used, which are precise but extremely time-consuming and unsuitable for high throughput. Addressing this issue, this study explores the application of femtosecond laser ablation in XRM sample preparation, emphasizing its advantages in achieving smooth, defect-free surfaces and precise material removal. Experimental results demonstrate the ability of femtosecond lasers to produce well-defined sample geometries, even in challenging materials such as metals, semiconductors, dielectrics and polymers, facilitating more accurate XRM measurements. Our findings underline the potential of femtosecond laser technology as a reliable, efficient, and versatile tool for enhancing XRM sample preparation workflows, paving the way for improved material characterization and advanced structural analysis.