The use of femtosecond lasers with up to 300 W average power available today necessitates advanced processing strategies to maximize both throughput and quality. Indeed, femtosecond lasers with high pulses energies or repetition rates can induce thermal effects, leading to material degradation and poor quality, undermining their well-known advantages. Several processing strategies can be proposed, but the beam division is very often required to obtain optimal results. In this work, we present a systematic study with a commercially available Spatial Light Modulator (SLM) using 1 to 50 spots beam division, parallel or perpendicular to the beam deflection by a galvo scanner. Considering the SLM power handling limitation the maximum power is 100 W, and the maximum pulse energy is 3 mJ.

In addition to commercial solutions, we also present an experimental study with an SLM setup, focused on the limitations in resolution and aberrations with such a device. To mitigate defects affecting experimental results in spot size and energy homogeneity, automatic feedback strategies are proposed. Issues such as modification of the target distribution and the presence of the 0th order are addressed, this dynamic correction of SLM modulation, based on real-time intensity observation, paves the way to overcoming SLM limitations and enhancing processing efficiency.