Shaping or splitting of a Gaussian beam is often desired to optimise laser–material interactions, improving throughput and quality. This can be achieved holographically using liquid crystal-on-silicon spatial light modulators (LC-SLMs). Until recently, maximum exposure has been limited to circa 120 W average power with a Gaussian profile, restricting potential applications due to the non-linear (NL) phase response of the liquid crystal above this threshold. In this study, we present experimental tests of a new SLM device, demonstrating high first-order diffraction efficiency of η = 0.98 ± 0.01 at 300 W average power and a phase range Δφ > 2π at P = 383 W, an exceptional performance. The numerically calculated device temperature response with power closely matches that measured, supporting the higher power-handling capability. Surface modification of mild steel and molybdenum up to P = 350 W exposure is demonstrated when employing a single-mode (SM) fibre laser source. Exposure on mild steel with a vortex beam (m = +6) displays numerous ringed regions with varying micro-structures and clear elemental separation created by the radial heat flow. On molybdenum, with multi-spot Gaussian exposure, both MoO₃ films and recrystallisation rings were observed, exposure-dependent. The step change in device capability will accelerate new applications for this LC-SLM in both subtractive and additive manufacturing.

Ultrashort-pulse laser processing enables selective layer removal in multilayer photovoltaic structures with precision and quality. Single-pulse ablation thresholds (1060 nm, 150 ps) were 1.15 J/cm² for ITO/glass and 0.14 J/cm² for ITO/PET. Photothermal mechanisms dominated the ablation on ITO/glass, whereas for ITO/PET, a stress-assisted thermomechanical mechanism was involved in the removal process. The charge-transporting AZO coating exhibited a single-layer ablation threshold of 0.21 J/cm² on ITO/glass, whereas the ablation threshold for an AZO/ITO stack was 0.71 J/cm². Compared to ITO alone, the notably lower single-pulse threshold for the AZO/ITO stack indicates that thin film removal mechanisms are influenced by interactions at the films’ interface rather than photon absorption alone. Similar incubation coefficients of ITO on glass and PET (0.93–0.94) suggest comparable pulse-to-pulse damage accumulation for ITO, coincident with dielectric incubation behaviour and regardless of the substrates. The study further showed that under 600 kHz processing with a 93.3% pulse overlap ratio, ITO could be entirely removed without substrate damage using the ablation threshold fluences. The methodology, demonstrated with industrially relevant coating of ITO and AZO, provides a valuable toolset to support the expanding portfolio of materials used in photovoltaic devices.

This study presents a phase-characterised optical set-up for shaped-beam femtosecond laser processing of double-sided lithium-ion battery anodes. The phase response was found to be power-independent, with consistent phase scaling across applied powers and a $2\pi$ phase shift completed at approximately 220–225 grey levels (GL). The measured modulation visibility stayed high. The generated beam profiles were in good agreement with MATLAB simulations, confirming reliable wavefront control. Under identical processing conditions, wavefronts carrying different orbital angular momentum (OAM) produced distinct kerf morphologies: at 30 overscans, $m=0$ gave a deeper cut with a taper angle of $16.5\pm 1.1°$, while $m=1$ gave a shallower groove with a less steep angle of $26.3\pm 1.9°$, indicating different Cu-layer interaction and ejecta behaviour. When the overscan number was increased to 45 at the same average power, both $m=0$ and $m=1$ achieved through-cuts. However, the $m=1$ condition produced a cleaner cut edge, a more vertical kerf wall, and reduced graphite delamination and heat-affected damage compared with the Gaussian beam. These results demonstrate the potential of wavefront engineering for laser processing of layered battery anodes, where improved cut confinement and edge quality can be achieved through beam shaping under relatively low-energy, moderate-overscan, and tight-focusing conditions.