Conference Agenda

In laser micromachining, the complex and non-linear laser-matter interaction prevents theoretical models from predicting optimal engraving parameters to meet time and quality criteria, often requiring numerous experimental tests for each new process to be developed. These traditional approaches are resource-intensive, requiring substantial machine and personnel time. To address these challenges, we propose an innovative methodology leveraging artificial intelligence (AI) to streamline the parameter optimization process. By combining a robust experimental database with advanced AI techniques, such as machine learning models and optimization algorithms, our approach enables the prediction of optimal laser parameters to meet dimensional and quality criteria without relying on exhaustive empirical testing for each new process.

Our latest results on this methodology will be presented, demonstrating its capacity to predict key parameters such as energy per pulse, speed, frequency, and pitch. This approach reduces resource consumption and accelerates process development, offering a transformative step forward in the field.

This research focuses on using femtosecond laser pulses for polymer cutting process optimization. Since polymers consist of very large molecules and are sensitive to heat, utilizing ultrashort pulse lasers can significantly expand their application potential in biomedical, micro-optics, and electronics fields. Polymers are getting more and more attention as a versatile material for biomedical, micro-optics and other applications where specific polymer properties are needed. During polymer cutting with femtosecond laser pulses better quality can be achieved avoiding heat affected zones (HAZ) due to indirect lattice heating, thus benefiting from “cold” ablation. We demonstrate cutting various thickness polyamide (PI), polyethylene (PET) and polycarbonate (PC) films. During experiments laser parameters such as pulse repetition rate, average power and pulse overlap were optimized to achieve high-quality efficient cuts and avoid HAZ. As a result, process parameters were optimized for each polymer cutting with ultrashort pulse laser.

This study investigates the behavior of three commercial polymers under high repetition rate (1 kHz–1 MHz), femtosecond (450 fs) laser irradiation at 1030 nm, 515 nm, and 343 nm, using different combinations of pulse numbers (100–400) and fluences (0.91–1.68 J/cm²). The influence of repetition rate and wavelength on ablation morphology is evaluated. At MHz repetition rates, larger ablation volumes and reduced thermal effects are observed. To interpret this behavior, we develop a simplified thermal diffusion model to estimate heat accumulation between pulses. The results suggest that, in the sub-MHz regime, heat removal by thermal decomposition dominates over diffusion losses, reducing average temperature rise — a behavior consistent with ablation cooling. This interpretation is supported by morphological measurements, indicating reduced thermal modifications at higher repetition rates. Observing ablation cooling below the GHz regime enables its analysis without shielding effects interference, providing insights into underlying heat diffusion mechanisms.

Solar cell production is entering the terawatt range. With laser- processing being an important part of silicon solar cell manufacturing, a laser tool is required to reach a throughput of over 10,000 wafers per hour (wph) with accuracies of 10-100 µm and small structure sizes (<30µm) over the full solar cell area.

To meet these demanding requirements, we have developed a new laser machine concept relying on on-the-fly processing and integrated tracking.

Velocity fluctuations on high-throughput conveyor belts are measured using custom optical tracking hardware, enabling real-time active oscillation compensation through synchronization with the laser scanner. With this approach the pattern oscillations through transport imperfections could be reduced from 82.2µm to 13.2µm (1σ).

To meet the necessary beam velocity of 1km/s and numerical aperture, polygon scanners are demonstrated to be well suited in combination with this on-the-fly processing approach, reaching a processing time of just 200ms for a full wafer.

Ultra-short pulse lasers open up new possibilities in the development of laser manufacturing processes with an extreme control of surface properties. For this reason, they have been introduced in several processes applied to damage-sensitive materials. This requires the introduction of monitoring technologies for the in-operando detection of phenomena occurring during the irradiation process. The latter can significantly affect the quality of the desired end result. This work presents acoustic monitoring as a powerful tool in several areas. These include the development of laser cleaning protocols for the preservation-restoration of stained glass in Cultural Heritage, the control of wettability in wind turbine blade surfaces, or the implementation of micromachining processes on ceramics and transparent conductive oxides with applications in the energy sector. An adequate analysis of the sound signal facilitates the selection of the most appropriate processing conditions and can also be used to evaluate the results of the laser treatment.

Tangential femtosecond laser micromachining is a modern technique suitable especially for machining hard materials with high precision in the manufacturing of rotary workpieces in a tangential position (laser turning). This study investigates the use of tungsten carbide rods with cobalt binder as a base material. Two machining strategies were tested: standard and adaptive. A closed-loop system combining a camera and software was used to monitor and control the process. The adaptive approach adjusted the laser path in real time to maintain the optimum angle of incidence (AOI) according to the changing geometry of the workpiece. The main objective of the research was to evaluate how AOI control affects material removal rate (MRR) against the standard approach. The results showed that adaptive control significantly increases MRR and process efficiency. These findings contribute to the development of tangential femtosecond laser micromachining for industrial applications requiring high-precision production of hard materials.